sumaira khan | Erciyes University (original) (raw)

Papers by sumaira khan

Research paper thumbnail of Evaluation of Essential Trace and Toxic Elements in Biological Samples of Normal and Night Blindness Children of Age Groups 3–7 and 8–12 Years

Biological Trace Element Research, 2010

The incidence of hypertension has been associated to cigarette smoking and consumption of alcohol... more The incidence of hypertension has been associated to cigarette smoking and consumption of alcohol. In the present study, trace and toxic elements were determined in scalp hair of patients diagnosed with hypertension who are smokers and habitual alcohol drinkers living in Dublin, Ireland. These results were compared with age-and sex-matched healthy, nonsmokers, nondrinking controls. The concentrations of trace and toxic elements were measured by inductively coupled plasma atomic emission spectrophotometer after microwave-assisted acid digestion. The validity and accuracy of the methodology were checked using certified reference material (NCS ZC 81002b) and by the conventional wet acid digestion method on the same certified reference material and on real samples. The recovery of all the studied elements was found to be in the range of 97.5%-99.7% in certified reference material. The results of this study showed that the mean values of cadmium, copper, iron, nickel and lead were significantly higher in scalp hair samples of both smoker and nonsmoker hypertensive patients than referents (P<0.001), whereas, the concentration of zinc was lower in the scalp hair samples of hypertensive patients of both genders. The deficiency of zinc and the high exposure of trace and toxic metals as a result of cigarette smoking and alcohol consumption may be synergistic with risk factors associated with hypertension.

Research paper thumbnail of Translocation of aluminum to grain crops grown in different agricultural systems

The aim of this study was to evaluate the mobility and transport of Aluminum (Al) by shoot and gr... more The aim of this study was to evaluate the mobility and transport of Aluminum (Al) by shoot and grain crops (wheat and maize) grown on two different agricultural soil irrigated with water have high (lake water) and low levels (canal water) of Al. The total and bioavailable fractions (deionized water, 0.11M CH 3 COOH, 0.05M ethylenediaminetetraaceticacid (EDTA) and 0.1 M HCl extractable) of Al in both understudied agricultural soils and correlate with respective total Al in the edible parts (grains) and non edible parts (Shoots) of wheat and maize. The Al content in lake and canal water samples was found in the range of 750-1340 and 90-150 µg/L respectively. The total and extractable Al in both agricultural soil samples, edible and non edible parts of wheat and maize were analysed by atomic absorption spectrometry after acid digestion in microwave oven. The edible and non edible part of both crops absorbed significantly high levels of Al grown on agricultural soil irrigated with lake water (SILW) as compared to those grown on soil irrigated with canal water (SICW) had low level of Al (p<0.01). The transfer factor of Al from soils to edible and non edible parts of wheat and maize were also evaluated. It was observed that the bioaccumulation of Al was found to be high in non edible parts of both crops grown in SILW. This study highlights the increased danger of growing food crops in the agricultural land continuously irrigated by Al contaminated lake water.

Research paper thumbnail of Vortex-assisted liquid–liquid microextraction coupled to flame atomic absorption spectrometry for lead determination: ionic liquid based microextraction using Triton X-100 as dispersant

Analytical Methods, 2012

Recently, a new and fast equilibrium-based solvent microextraction technique termed vortex-assist... more Recently, a new and fast equilibrium-based solvent microextraction technique termed vortex-assisted liquid-liquid microextraction was developed. In this technique, the dispersion of the extraction solvent is enhanced by vortex mixing. The aim of the present review is to discuss the applications of vortex agitation in solvent-microextraction procedures. Keywords vortex-assisted • Liquid-liquid microextraction • HPLC • GC • Organic and inorganic compounds Abbreviations APDC Ammonium pyrrolidinethiocarbamate BPA Bisphenol-A CTAB Cetylthimethyl ammonium bromide CvAFS Cold vapour atomic fluorescence spectrometry DAD Diode array detection DLLMe Dispersive liquid-liquid microextraction DNSUAMe Dispersive nano-solid material-ultrasound assisted microextraction FAAS Flame atomic absorption spectrometry FLD Fluorescence detection FPD Flame photometric detection GC Gas chromatography GC-FID Gas chromatography-flame ionization detection GC-FPD Gas chromatography-flame photometric detection

Research paper thumbnail of Development of Extraction Methods for Speciation Analysis of Selenium in Aqueous Extracts of Medicinal Plants

Journal of AOAC …, 2011

Résumé/Abstract Advanced extraction methods have been developed for direct speciation of dissolve... more Résumé/Abstract Advanced extraction methods have been developed for direct speciation of dissolved inorganic and organic selenium (Se) species in aqueous extracts of medicinal plants (MPs). The inorganic species of Se (Se IV and Se VI) were separated from organic ...

Research paper thumbnail of Effects of selenium supplementation on iodine and thyroid hormone status in a selected population with goitre in Pakistan

Clinical Laboratory, 2011

Background: Selenium (Se) has an essential role in thyroid hormone metabolism. It has the potenti... more Background: Selenium (Se) has an essential role in thyroid hormone metabolism. It has the potential to play a major part in the outcome of iodine (I) deficiency The aim of the present study was to evaluate the Se and I status of biological samples (serum and urine) of 160 goitrous male (GMPs) and 195 female patients (GFPs). The supplemental effects of Se (200 microg/day) and I (100 - 125 microg/day) were evaluated after 6 months. For comparison purposes, non-goitrous subjects of both genders (n = 440) with same age group and socioeconomic status were also selected. Methods: Hydride generation atomic absorption spectrometry (HGAAS) was used to investigate the Se concentration in the biological samples, prior to microwave assisted acid digestion. Quality control for the methodology was established by comparing the results obtained with certified samples with those obtained by conventional wet acid digestion method on the same CRMs and real samples. Results: The mean serum Se concentration was significantly lower, while urinary Se was higher in GMPs and GFPs as compared to control subjects (p < 0.005 and < 0.007, respectively). The levels of I, free tri-iodothyronine, and thyroxin were found in goitrous patients of both genders were low compared to age matched healthy controls (p < 0.015, < 0.006, and < 0.002, respectively). On the other hand, high levels of thyroid stimulating hormone were observed in GMPs and GFPs (p < 0.009). Conclusions: It was observed that Se in biological samples of hypothyroid patients can play an important role in determining the severity of the hypothyroidism associated with iodine deficiency. A wide-scale epidemiological study is recommended together with the examination of the potential preventive role of Se supplementation in endemic goiter regions.

Research paper thumbnail of Ionic Liquid-Based Ultrasound-Assisted Emulsification Microextraction of Cadmium in Biological Samples: Optimization by a Multivariate Approach

Http Dx Doi Org 10 1080 00032719 2014 999280, Jan 12, 2015

ABSTRACT An ionic liquid-based ultrasound-assisted emulsification microextraction method was deve... more ABSTRACT An ionic liquid-based ultrasound-assisted emulsification microextraction method was developed for the preconcentration and determination of cadmium followed by flame atomic absorption spectrometry. Cadmium was complexed with 4-(2-pyridylazo) resorcinol, and then extracted into fine drops of 1-butyl-3-methylimidazolium hexafluorophosphate that served as the ionic liquid. The pH, ligand concentration, volume of ionic liquid, sonication time, and temperature were optimized by a multivariate technique. The results showed that concomitant ions did not affect the determination of cadmium. The detection limit and enhancement factor under the optimal conditions were 0.21 micrograms per liter and 92, respectively. The relative standard deviation of 10 micrograms per liter of cadmium was less than 5.0 percent. The validity of the method was investigated by the analysis of a spinach leaves standard reference material. The method was suitable for the preconcentration of cadmium in food and biological samples.

Research paper thumbnail of Determination of selenium content in aqueous extract of medicinal plants used as herbal supplement for cancer patients

Food and Chemical Toxicology an International Journal Published For the British Industrial Biological Research Association, Dec 1, 2010

The chemical constituents in medicinal plants (MPs), including elements, are partially responsibl... more The chemical constituents in medicinal plants (MPs), including elements, are partially responsible for their medicinal and nutritional properties as well as toxic effects. This research aimed to monitor selenium (Se) contents in aqueous extract of MPs used for treatment of cancer and different diseases. In present work the Se in MPs was extracted in aqueous media by microwave-assisted (ME) and conventional extraction (CE) methods. The total and residual Se in MPs were determined, prior to microwave-assisted acid digestion. The Se in aqueous extracts and digests were analysed by electrothermal atomic absorption spectrometry. The optimum extractable Se in MPs were obtained by ME and CE, required 2 and 40 min, respectively. Precision and accuracy of the methodologies were checked by standard addition method. The Se contents in aqueous extract of MPs were found in the range of 1.09-2.23 μg/g corresponding to 21-33% of total Se contents. The daily intake of Se from aqueous extract of MPs as recommended by herbalist (10 g of plant material) was found in the range of 20-40% of daily requirement.

Research paper thumbnail of Evaluation of zinc in scalp hair and blood samples of tuberculosis and diarrhea male human immunodeficiency virus patients

Clinical Laboratory, 2011

The consequence of zinc (Zn) deficiency has been associated with an increased risk of human immun... more The consequence of zinc (Zn) deficiency has been associated with an increased risk of human immunodeficiency virus type 1 (HIV-1) disease progression and mortality. This study examined the association between low scalp hair and blood Zn concentrations and opportunistic infections in hospitalized patients with the acquired immune deficiency syndrome (AIDS). The study was performed on sixty two male HIV+ patients (HIV-1) from different cities in Pakistan. The patients were divided in two groups according to secondary infections (tuberculosis, diarrhea, and high fever). The biological samples (scalp hair and blood) were collected from AIDS patients, and for comparative study, 120 healthy subjects (males) of same age group (31 - 45 years), socio-economic status, localities, and dietary habits were also included. The Zn in biological samples was determined by flame atomic absorption spectrometry prior to microwave assisted acid digestion. The proposed method was validated by a certified sample of human hair BCR 397 and Clincheck control-lyophilized human whole blood. It was observed that the low levels of Zn may be predictors for secondary infections in HIV-1 patients. There was a significant decrease in mean values of Zn in whole blood and scalp hair samples in both groups of AIDS patients as compared to a controlled healthy male group (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001). Deficiency of zinc might play a role in the development of AIDS in the subjects of this study.

Research paper thumbnail of Evaluation of arsenic, cadmium, lead, nickel, and zinc in biological samples (scalp hair, blood, and urine) of tuberculosis and diarrhea male human immunodeficiency virus patients

Clinical Laboratory, 2011

The consequence of a deficiency in trace elements has been associated with an increased risk of h... more The consequence of a deficiency in trace elements has been associated with an increased risk of human immunodeficiency virus type 1 (HIV-1) disease progression and mortality. This study examined the association between high scalp hair and blood arsenic, cadmium, lead, and nickel concentrations and opportunistic infections in hospitalized patients with the acquired immune deficiency syndrome (AIDS). The study was performed on sixty two male HIV+ patients (HIV-1) from different cities of Pakistan. The patients were divided in two groups according to secondary infections (tuberculosis, diarrhea, and high fever). The biological samples (scalp hair, blood, and urine) were collected from AIDS patients, and for comparative study 120 healthy subjects (males) of same age group (31 - 45 years), socio-economic status, localities, and dietary habits were also included. The elements in the biological samples were analyzed by electrothermal atomic absorption spectrophotometry, prior to microwave-assisted acid digestion. The validity and accuracy of the methodology was checked using certified reference materials (CRMs) and with values obtained by conventional wet acid digestion method on same CRMs. The results indicated significantly higher levels of As, Cd, Ni, and Pb in the biological samples (scalp hair, blood, and urine) of male HIV-1 patients, compared with control subjects. It was observed that the high levels of these toxic elements may be predictors for secondary infections in HIV-1 patients. There was a significant increase in mean values of As, Cd, Ni, and Pb in whole blood, scalp hair, and urine samples of three groups of AIDS patients as compared to a controlled healthy male group (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001). These data present guidance to clinicians and other professionals investigating toxicity of As, Cd, Ni, and Pb in biological samples of AIDS patients.

Research paper thumbnail of Simultaneously removal of inorganic arsenic species from stored rainwater in arsenic endemic area by leaves of Tecomella undulata: a multivariate study

Environmental Science and Pollution Research, 2016

In the present study, an indigenous biosorbent (leaves of Tecomella undulata) was used for the si... more In the present study, an indigenous biosorbent (leaves of Tecomella undulata) was used for the simultaneous removal of inorganic arsenic species (As(III) and As(V)) from the stored rainwater in Tharparkar, Pakistan. The Plackett-Burman experimental design was used as a multivariate strategy for the evaluation of the effects of six factors/variables on the biosorption of inorganic arsenic species, simultaneously. Central composite design (CCD) was used to found the optimum values of significant factors for the removal of As(III) and As(V). Initial concentrations of both inorganic As species, pH, biosorbent dose, and contact time were selected as independent factors in CCD, while the adsorption capacity (q e) was considered as a response function. The separation of inorganic As species in water samples before and after biosorption was carried out by cloud point and solid-phase extraction methods. Theoretical values of pH, concentration of analytes, biosorbent dose, and contact time were calculated by quadratic equation for 100 % biosorption of both inorganic As species in aqueous media. Experimental data were modeled by Langmuir and Freundlich isotherms. Thermodynamic and kinetic study indicated that the biosorption of As(III) and As(V) was followed by pseudo second order. It was concluded that the indigenous biosorbent material efficiently and simultaneously removed both As species in the range of 70.8 to 98.5 % of total contents in studied ground water samples. Graphical abstract Optimizing the significant varable by central 2(3) + star orthogonal composite design.

Research paper thumbnail of Interaction between selenium and arsenic in biological samples of psoriasis patients

Clinical Laboratory, 2012

Background: Psoriasis is a noncontagious, chronic skin disease affecting 1 in 50 people worldwide... more Background: Psoriasis is a noncontagious, chronic skin disease affecting 1 in 50 people worldwide. Methods: The aim of present study was to compare the levels of arsenic (As) and selenium (Se) in samples of whole blood, urine, and scalp hair of 418 psoriasis patients of both genders aged 25 - 55 years. All psoriatic patients lived in the vicinity of a cement factory, and were categorized as mild, moderate, and severe. For comparison purposes, 395 healthy age-matched referent/control subjects, residents of industrial and non-industrial areas, were selected. The concentrations of essential trace and toxic elements were measured by electrothermal atomic absorption spectroscopy after microwave-assisted acid digestion. The validity and accuracy of methodology was checked by using certified reference materials (CRMs) and the conventional wet acid digestion method on the same CRMs and real samples. Results: The observed mean values of As were significantly higher in scalp hair, blood, and urine samples of patients with mild and severe psoriasis as compared to the controls (p = 0.01 - 0.001), while the concentrations of Se were lower in the scalp hair and blood, but higher in the urine samples of psoriasis patients of all categories. Conclusions: The deficiency of Se in psoriatic patients may undoubtedly be caused by the toxic element exposures via dust produced by the cement factory.

Research paper thumbnail of Microwave-assisted acid extraction of selenium from medicinal plants followed by electrothermal atomic absorption spectrometric determination

Journal of AOAC International

A simple and rapid microwave-assisted extraction (MAE) of selenium (Se) from medicinal plants was... more A simple and rapid microwave-assisted extraction (MAE) of selenium (Se) from medicinal plants was investigated using different concentrations of nitric acid and hydrochloric acid, sample mass, heating time, microwave energy, and plant particle size. The optimization strategy was carried out using multivariate methodologies. Electrothermal atomic absorption spectrometry was used to determine Se. The accuracy of the optimized procedure was evaluated by using certified reference materials with certified values for Se and a microwave-assisted acid digestion (MD) method for comparative purpose. No significant difference was observed (P > 0.05) when comparing the values obtained by the proposed MAE and MD methods (paired t-test). Under the optimum operating conditions, the LOD obtained from the standard calibration curve was 0.012 microg/L for Se. The average RSD of the MAE method varied between 4.05 and 7.53% (n = 6). The proposed method was successfully applied for the determination ...

Research paper thumbnail of Preconcentration and determination of lead and cadmium levels in blood samples of adolescent workers consuming smokeless tobacco products in Pakistan

Environmental Monitoring and Assessment, 2015

The present study was aimed to evaluate the cadmium (Cd) and lead (Pb) levels in the blood sample... more The present study was aimed to evaluate the cadmium (Cd) and lead (Pb) levels in the blood samples of adolescent boys, chewing different smokeless tobacco (SLT) products in Pakistan. For comparative purpose, boys of the same age group (12-15 years), not consumed any SLT products were selected as referents. To determine trace levels of Cd and Pb in blood samples, a preconcentration method, vortex-assisted liquid-liquid microextraction (VLLME) has been developed, prior to analysis by flame atomic absorption spectrometry. The hydrophobic chelates of Cd and Pb with ammonium pyrrolidinedithiocarbamate were extracted into the fine droplets of ionic liquid (IL) 1-butyl-3-methylimidazolium hexafluorophosphate, while nonionic surfactant, Triton X-114 was used as a dispersing medium. The main factors affecting the recoveries of Cd and Pb, such as concentration of APDC, centrifugation time, volume of IL and TX-114, were investigated in detail. It was also observed that adolescent boys who consumed different SLT products have 2- to 3-fold higher levels of Cd and Pb in their blood samples as compared to referent boys (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001).

Research paper thumbnail of Evaluation of arsenic, cadmium, lead, nickel, and zinc in biological samples (scalp hair, blood, and urine) of tuberculosis and diarrhea male human immunodeficiency virus patients

Clinical laboratory, 2011

The consequence of a deficiency in trace elements has been associated with an increased risk of h... more The consequence of a deficiency in trace elements has been associated with an increased risk of human immunodeficiency virus type 1 (HIV-1) disease progression and mortality. This study examined the association between high scalp hair and blood arsenic, cadmium, lead, and nickel concentrations and opportunistic infections in hospitalized patients with the acquired immune deficiency syndrome (AIDS). The study was performed on sixty two male HIV+ patients (HIV-1) from different cities of Pakistan. The patients were divided in two groups according to secondary infections (tuberculosis, diarrhea, and high fever). The biological samples (scalp hair, blood, and urine) were collected from AIDS patients, and for comparative study 120 healthy subjects (males) of same age group (31 - 45 years), socio-economic status, localities, and dietary habits were also included. The elements in the biological samples were analyzed by electrothermal atomic absorption spectrophotometry, prior to microwave-...

Research paper thumbnail of Evaluation of zinc, copper and iron in biological samples (scalp hair, blood and urine) of tuberculosis and diarrhea male human immunodeficiency virus patients

Clinical laboratory, 2011

The consequence of a deficiency in trace elements has been associated with an increased risk of h... more The consequence of a deficiency in trace elements has been associated with an increased risk of human immunodeficiency virus type 1 (HIV-1) disease progression and mortality. This study examined the association between low scalp hair and blood zinc, copper, and iron concentrations and opportunistic infections in hospitalized patients with the acquired immune deficiency syndrome (AIDS). The study was performed on sixty two male HIV+ patients (HIV-1) from different cities in Pakistan. The patients were divided in two groups according to secondary infections (tuberculosis, diarrhea and high fever). The biological samples (scalp hair, blood, and urine) were collected from AIDS patients. For comparative study, 120 healthy subjects (males) of the same age group (31 - 45 years), socio-economic status, localities, and dietary habits were also included. The elements in the biological samples were analyzed by flame atomic absorption spectrophotometry prior to microwave-assisted acid digestion...

Research paper thumbnail of Evaluation of status of calcium, magnesium, potassium, and sodium levels in biological samples in children of different age groups with normal vision and night blindness

Clinical laboratory, 2011

The most common cause of blindness in developing countries is vitamin A deficiency. The World Hea... more The most common cause of blindness in developing countries is vitamin A deficiency. The World Health Organization (WHO) estimates 13.8 million children have some degree of visual loss related to vitamin A deficiency. The causes of night blindness in children are multifactorial and particular consideration has been given to childhood nutritional deficiency, which is the most common problem found in underdeveloped countries. Such deficiency can result in physiological and pathological processes that in turn influence biological sample composition. Vitamin and mineral deficiency prevents more than two billion people from achieving their full intellectual and physical potential. This study was designed to compare the levels of magnesium (Mg), calcium (Ca), potassium (K), and sodium (Na) in scalp hair, serum, blood, and urine of night blindness children in two age groups, (1-5) and (6-10) years, of both genders comparing them to sex- and age-matched controls. A microwave assisted wet aci...

Research paper thumbnail of Determination of arsenic in scalp hair samples from exposed subjects using microwave-assisted digestion with and without enrichment based on cloud point extraction by electrothermal atomic absorption spectrometry

Journal of AOAC International

A simple and rapid cloud point extraction (CPE) procedure was applied for preconcentration of tra... more A simple and rapid cloud point extraction (CPE) procedure was applied for preconcentration of trace quantities of arsenic (As) in scalp hair samples. The samples were subjected to microwave-assisted digestion in a mixture of nitric acid and hydrogen peroxide (2 + 1, v/v) prior to preconcentration by CPE. The As in digested samples was complexed with ammonium pyrrolidine dithiocarbamate (APDC), and the resultant As-PDC complex was extracted by a nonionic surfactant, octylphenoxypolyethoxyethanol (Triton X-114). After centrifugation, the surfactant-rich phase was diluted with 0.1 M HNO3 in methanol and analyzed by electrothermal atomic absorption spectrometry. The experimental parameters, i.e., amount of APDC, concentration of Triton X-114, equilibrium temperature and time, were optimized. For validation of the proposed method, a certified reference material (CRM) of human hair (BCR 397) was used. No significant difference (P > 0.05) was observed between the experimental results an...

Research paper thumbnail of A green and efficient in-syringe ionic liquid-based single step microextraction procedure for preconcentration and determination of cadmium in water samples

Journal of Industrial and Engineering Chemistry, 2015

ABSTRACT An in-syringe ionic liquid-based single step microextraction has been analytically prese... more ABSTRACT An in-syringe ionic liquid-based single step microextraction has been analytically presented. 1-butyl-3-methylimidazolium hexafluorophosphate as extractant and Triton X-100 as dispersing medium were used. Cd-Dithizone was extracted within a syringe. The effects of some variables such as [C4mim][PF6] volume, pH, TX-100 volume, dithizone concentration, incubation time, diluents nature and matrix effect were investigated. The limit of detection and preconcentration factor were found as 0.35 μg L−1 and 50, respectively. The validity was checked by using certified reference materials. The relative standard deviation (RSD) was 4.2%. The method was satisfactorily applied to preconcentration of cadmium in natural water samples.

Research paper thumbnail of Room Temperature Ionic Liquid-Based Dispersive Liquid Phase Microextraction for the Separation/Preconcentration of Trace Cd2+ as 1-(2-pyridylazo)-2-naphthol (PAN) Complex from Environmental and Biological Samples and Determined by FAAS

Biological Trace Element Research, 2013

The current work develops a new green methodology for the separation/preconcentration of cadmium ... more The current work develops a new green methodology for the separation/preconcentration of cadmium ions (Cd(2+)) using room temperature ionic liquid-dispersive liquid phase microextraction (RTIL-DLME) prior to analysis by flame atomic absorption spectrometry with microsample introduction system. Room temperature ionic liquids (RTIL) are considered &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;Green Solvents&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; for their thermally stable and non-volatile properties, here 1-butyl-3-methylimidazolium hexafluorophosphate [C4mim][PF6] was used as an extractant. The preconcentration of Cd(2+) in different waters and acid digested scalp hair samples were complexed with 1-(2-pyridylazo)-2-naphthol and extracted into the fine drops of RTILs. Some significant factors influencing the extraction efficiency of Cd(2+) and its subsequent determination, including pH, amount of ligand, volume of RTIL, dispersant solvent, sample volume, temperature, and incubation time were investigated in detail. The limit of detection and the enhancement factor under the optimal conditions were 0.05 μg/L and 50, respectively. The relative standard deviation of 100 μg/L Cd(2+) was 4.3 %. The validity of the proposed method was checked by determining Cd(2+) in certified reference material (TM-25.3 fortified water). The sufficient recovery (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;98 %) of Cd(2+) with the certified value. The mean concentrations of Cd in lake water 13.2, waste water 15.7 and hair sample 16.8 μg/L, respectively and the developed method was applied satisfactorily to the preconcentration and determination of Cd(2+) in real samples.

Research paper thumbnail of Determination of Arsenic in Scalp Hair of Children and its Correlation with Drinking Water in Exposed Areas of Sindh Pakistan

Biological Trace Element Research, 2010

This study was focused on the analysis of arsenic (As) levels in scalp hair of children (age, <10... more This study was focused on the analysis of arsenic (As) levels in scalp hair of children (age, <10 years) collected from two towns of Khairpur, Pakistan, to evaluate the effects of As-contaminated groundwater. For comparative purposes, scalp hair samples of children were also collected from that area having low levels of As (<10 μg/L) in drinking water. Groundwater and scalp hair samples of children were collected and analyzed by electrothermal atomic absorption spectrometry prior to microwave-assisted acid digestion. The average As concentrations in groundwater samples of two towns, Thari Mirwah and Gambat, were found to be 28.5 and 98.3 μg/L, respectively. The range of As concentrations in scalp hair samples of children who belong to Thari Mirwah and Gambat was 1.25-1.61 μg/g and 1.73-3.63 μg/g, respectively. Twenty percent of the total children who belong to Gambat have skin lesions on their hands and feet. A positive correlation coefficient (R=0.91-0.99) was obtained between As contents in drinking water and scalp hairs of children of both towns.

Research paper thumbnail of Evaluation of Essential Trace and Toxic Elements in Biological Samples of Normal and Night Blindness Children of Age Groups 3–7 and 8–12 Years

Biological Trace Element Research, 2010

The incidence of hypertension has been associated to cigarette smoking and consumption of alcohol... more The incidence of hypertension has been associated to cigarette smoking and consumption of alcohol. In the present study, trace and toxic elements were determined in scalp hair of patients diagnosed with hypertension who are smokers and habitual alcohol drinkers living in Dublin, Ireland. These results were compared with age-and sex-matched healthy, nonsmokers, nondrinking controls. The concentrations of trace and toxic elements were measured by inductively coupled plasma atomic emission spectrophotometer after microwave-assisted acid digestion. The validity and accuracy of the methodology were checked using certified reference material (NCS ZC 81002b) and by the conventional wet acid digestion method on the same certified reference material and on real samples. The recovery of all the studied elements was found to be in the range of 97.5%-99.7% in certified reference material. The results of this study showed that the mean values of cadmium, copper, iron, nickel and lead were significantly higher in scalp hair samples of both smoker and nonsmoker hypertensive patients than referents (P<0.001), whereas, the concentration of zinc was lower in the scalp hair samples of hypertensive patients of both genders. The deficiency of zinc and the high exposure of trace and toxic metals as a result of cigarette smoking and alcohol consumption may be synergistic with risk factors associated with hypertension.

Research paper thumbnail of Translocation of aluminum to grain crops grown in different agricultural systems

The aim of this study was to evaluate the mobility and transport of Aluminum (Al) by shoot and gr... more The aim of this study was to evaluate the mobility and transport of Aluminum (Al) by shoot and grain crops (wheat and maize) grown on two different agricultural soil irrigated with water have high (lake water) and low levels (canal water) of Al. The total and bioavailable fractions (deionized water, 0.11M CH 3 COOH, 0.05M ethylenediaminetetraaceticacid (EDTA) and 0.1 M HCl extractable) of Al in both understudied agricultural soils and correlate with respective total Al in the edible parts (grains) and non edible parts (Shoots) of wheat and maize. The Al content in lake and canal water samples was found in the range of 750-1340 and 90-150 µg/L respectively. The total and extractable Al in both agricultural soil samples, edible and non edible parts of wheat and maize were analysed by atomic absorption spectrometry after acid digestion in microwave oven. The edible and non edible part of both crops absorbed significantly high levels of Al grown on agricultural soil irrigated with lake water (SILW) as compared to those grown on soil irrigated with canal water (SICW) had low level of Al (p<0.01). The transfer factor of Al from soils to edible and non edible parts of wheat and maize were also evaluated. It was observed that the bioaccumulation of Al was found to be high in non edible parts of both crops grown in SILW. This study highlights the increased danger of growing food crops in the agricultural land continuously irrigated by Al contaminated lake water.

Research paper thumbnail of Vortex-assisted liquid–liquid microextraction coupled to flame atomic absorption spectrometry for lead determination: ionic liquid based microextraction using Triton X-100 as dispersant

Analytical Methods, 2012

Recently, a new and fast equilibrium-based solvent microextraction technique termed vortex-assist... more Recently, a new and fast equilibrium-based solvent microextraction technique termed vortex-assisted liquid-liquid microextraction was developed. In this technique, the dispersion of the extraction solvent is enhanced by vortex mixing. The aim of the present review is to discuss the applications of vortex agitation in solvent-microextraction procedures. Keywords vortex-assisted • Liquid-liquid microextraction • HPLC • GC • Organic and inorganic compounds Abbreviations APDC Ammonium pyrrolidinethiocarbamate BPA Bisphenol-A CTAB Cetylthimethyl ammonium bromide CvAFS Cold vapour atomic fluorescence spectrometry DAD Diode array detection DLLMe Dispersive liquid-liquid microextraction DNSUAMe Dispersive nano-solid material-ultrasound assisted microextraction FAAS Flame atomic absorption spectrometry FLD Fluorescence detection FPD Flame photometric detection GC Gas chromatography GC-FID Gas chromatography-flame ionization detection GC-FPD Gas chromatography-flame photometric detection

Research paper thumbnail of Development of Extraction Methods for Speciation Analysis of Selenium in Aqueous Extracts of Medicinal Plants

Journal of AOAC …, 2011

Résumé/Abstract Advanced extraction methods have been developed for direct speciation of dissolve... more Résumé/Abstract Advanced extraction methods have been developed for direct speciation of dissolved inorganic and organic selenium (Se) species in aqueous extracts of medicinal plants (MPs). The inorganic species of Se (Se IV and Se VI) were separated from organic ...

Research paper thumbnail of Effects of selenium supplementation on iodine and thyroid hormone status in a selected population with goitre in Pakistan

Clinical Laboratory, 2011

Background: Selenium (Se) has an essential role in thyroid hormone metabolism. It has the potenti... more Background: Selenium (Se) has an essential role in thyroid hormone metabolism. It has the potential to play a major part in the outcome of iodine (I) deficiency The aim of the present study was to evaluate the Se and I status of biological samples (serum and urine) of 160 goitrous male (GMPs) and 195 female patients (GFPs). The supplemental effects of Se (200 microg/day) and I (100 - 125 microg/day) were evaluated after 6 months. For comparison purposes, non-goitrous subjects of both genders (n = 440) with same age group and socioeconomic status were also selected. Methods: Hydride generation atomic absorption spectrometry (HGAAS) was used to investigate the Se concentration in the biological samples, prior to microwave assisted acid digestion. Quality control for the methodology was established by comparing the results obtained with certified samples with those obtained by conventional wet acid digestion method on the same CRMs and real samples. Results: The mean serum Se concentration was significantly lower, while urinary Se was higher in GMPs and GFPs as compared to control subjects (p < 0.005 and < 0.007, respectively). The levels of I, free tri-iodothyronine, and thyroxin were found in goitrous patients of both genders were low compared to age matched healthy controls (p < 0.015, < 0.006, and < 0.002, respectively). On the other hand, high levels of thyroid stimulating hormone were observed in GMPs and GFPs (p < 0.009). Conclusions: It was observed that Se in biological samples of hypothyroid patients can play an important role in determining the severity of the hypothyroidism associated with iodine deficiency. A wide-scale epidemiological study is recommended together with the examination of the potential preventive role of Se supplementation in endemic goiter regions.

Research paper thumbnail of Ionic Liquid-Based Ultrasound-Assisted Emulsification Microextraction of Cadmium in Biological Samples: Optimization by a Multivariate Approach

Http Dx Doi Org 10 1080 00032719 2014 999280, Jan 12, 2015

ABSTRACT An ionic liquid-based ultrasound-assisted emulsification microextraction method was deve... more ABSTRACT An ionic liquid-based ultrasound-assisted emulsification microextraction method was developed for the preconcentration and determination of cadmium followed by flame atomic absorption spectrometry. Cadmium was complexed with 4-(2-pyridylazo) resorcinol, and then extracted into fine drops of 1-butyl-3-methylimidazolium hexafluorophosphate that served as the ionic liquid. The pH, ligand concentration, volume of ionic liquid, sonication time, and temperature were optimized by a multivariate technique. The results showed that concomitant ions did not affect the determination of cadmium. The detection limit and enhancement factor under the optimal conditions were 0.21 micrograms per liter and 92, respectively. The relative standard deviation of 10 micrograms per liter of cadmium was less than 5.0 percent. The validity of the method was investigated by the analysis of a spinach leaves standard reference material. The method was suitable for the preconcentration of cadmium in food and biological samples.

Research paper thumbnail of Determination of selenium content in aqueous extract of medicinal plants used as herbal supplement for cancer patients

Food and Chemical Toxicology an International Journal Published For the British Industrial Biological Research Association, Dec 1, 2010

The chemical constituents in medicinal plants (MPs), including elements, are partially responsibl... more The chemical constituents in medicinal plants (MPs), including elements, are partially responsible for their medicinal and nutritional properties as well as toxic effects. This research aimed to monitor selenium (Se) contents in aqueous extract of MPs used for treatment of cancer and different diseases. In present work the Se in MPs was extracted in aqueous media by microwave-assisted (ME) and conventional extraction (CE) methods. The total and residual Se in MPs were determined, prior to microwave-assisted acid digestion. The Se in aqueous extracts and digests were analysed by electrothermal atomic absorption spectrometry. The optimum extractable Se in MPs were obtained by ME and CE, required 2 and 40 min, respectively. Precision and accuracy of the methodologies were checked by standard addition method. The Se contents in aqueous extract of MPs were found in the range of 1.09-2.23 μg/g corresponding to 21-33% of total Se contents. The daily intake of Se from aqueous extract of MPs as recommended by herbalist (10 g of plant material) was found in the range of 20-40% of daily requirement.

Research paper thumbnail of Evaluation of zinc in scalp hair and blood samples of tuberculosis and diarrhea male human immunodeficiency virus patients

Clinical Laboratory, 2011

The consequence of zinc (Zn) deficiency has been associated with an increased risk of human immun... more The consequence of zinc (Zn) deficiency has been associated with an increased risk of human immunodeficiency virus type 1 (HIV-1) disease progression and mortality. This study examined the association between low scalp hair and blood Zn concentrations and opportunistic infections in hospitalized patients with the acquired immune deficiency syndrome (AIDS). The study was performed on sixty two male HIV+ patients (HIV-1) from different cities in Pakistan. The patients were divided in two groups according to secondary infections (tuberculosis, diarrhea, and high fever). The biological samples (scalp hair and blood) were collected from AIDS patients, and for comparative study, 120 healthy subjects (males) of same age group (31 - 45 years), socio-economic status, localities, and dietary habits were also included. The Zn in biological samples was determined by flame atomic absorption spectrometry prior to microwave assisted acid digestion. The proposed method was validated by a certified sample of human hair BCR 397 and Clincheck control-lyophilized human whole blood. It was observed that the low levels of Zn may be predictors for secondary infections in HIV-1 patients. There was a significant decrease in mean values of Zn in whole blood and scalp hair samples in both groups of AIDS patients as compared to a controlled healthy male group (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001). Deficiency of zinc might play a role in the development of AIDS in the subjects of this study.

Research paper thumbnail of Evaluation of arsenic, cadmium, lead, nickel, and zinc in biological samples (scalp hair, blood, and urine) of tuberculosis and diarrhea male human immunodeficiency virus patients

Clinical Laboratory, 2011

The consequence of a deficiency in trace elements has been associated with an increased risk of h... more The consequence of a deficiency in trace elements has been associated with an increased risk of human immunodeficiency virus type 1 (HIV-1) disease progression and mortality. This study examined the association between high scalp hair and blood arsenic, cadmium, lead, and nickel concentrations and opportunistic infections in hospitalized patients with the acquired immune deficiency syndrome (AIDS). The study was performed on sixty two male HIV+ patients (HIV-1) from different cities of Pakistan. The patients were divided in two groups according to secondary infections (tuberculosis, diarrhea, and high fever). The biological samples (scalp hair, blood, and urine) were collected from AIDS patients, and for comparative study 120 healthy subjects (males) of same age group (31 - 45 years), socio-economic status, localities, and dietary habits were also included. The elements in the biological samples were analyzed by electrothermal atomic absorption spectrophotometry, prior to microwave-assisted acid digestion. The validity and accuracy of the methodology was checked using certified reference materials (CRMs) and with values obtained by conventional wet acid digestion method on same CRMs. The results indicated significantly higher levels of As, Cd, Ni, and Pb in the biological samples (scalp hair, blood, and urine) of male HIV-1 patients, compared with control subjects. It was observed that the high levels of these toxic elements may be predictors for secondary infections in HIV-1 patients. There was a significant increase in mean values of As, Cd, Ni, and Pb in whole blood, scalp hair, and urine samples of three groups of AIDS patients as compared to a controlled healthy male group (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001). These data present guidance to clinicians and other professionals investigating toxicity of As, Cd, Ni, and Pb in biological samples of AIDS patients.

Research paper thumbnail of Simultaneously removal of inorganic arsenic species from stored rainwater in arsenic endemic area by leaves of Tecomella undulata: a multivariate study

Environmental Science and Pollution Research, 2016

In the present study, an indigenous biosorbent (leaves of Tecomella undulata) was used for the si... more In the present study, an indigenous biosorbent (leaves of Tecomella undulata) was used for the simultaneous removal of inorganic arsenic species (As(III) and As(V)) from the stored rainwater in Tharparkar, Pakistan. The Plackett-Burman experimental design was used as a multivariate strategy for the evaluation of the effects of six factors/variables on the biosorption of inorganic arsenic species, simultaneously. Central composite design (CCD) was used to found the optimum values of significant factors for the removal of As(III) and As(V). Initial concentrations of both inorganic As species, pH, biosorbent dose, and contact time were selected as independent factors in CCD, while the adsorption capacity (q e) was considered as a response function. The separation of inorganic As species in water samples before and after biosorption was carried out by cloud point and solid-phase extraction methods. Theoretical values of pH, concentration of analytes, biosorbent dose, and contact time were calculated by quadratic equation for 100 % biosorption of both inorganic As species in aqueous media. Experimental data were modeled by Langmuir and Freundlich isotherms. Thermodynamic and kinetic study indicated that the biosorption of As(III) and As(V) was followed by pseudo second order. It was concluded that the indigenous biosorbent material efficiently and simultaneously removed both As species in the range of 70.8 to 98.5 % of total contents in studied ground water samples. Graphical abstract Optimizing the significant varable by central 2(3) + star orthogonal composite design.

Research paper thumbnail of Interaction between selenium and arsenic in biological samples of psoriasis patients

Clinical Laboratory, 2012

Background: Psoriasis is a noncontagious, chronic skin disease affecting 1 in 50 people worldwide... more Background: Psoriasis is a noncontagious, chronic skin disease affecting 1 in 50 people worldwide. Methods: The aim of present study was to compare the levels of arsenic (As) and selenium (Se) in samples of whole blood, urine, and scalp hair of 418 psoriasis patients of both genders aged 25 - 55 years. All psoriatic patients lived in the vicinity of a cement factory, and were categorized as mild, moderate, and severe. For comparison purposes, 395 healthy age-matched referent/control subjects, residents of industrial and non-industrial areas, were selected. The concentrations of essential trace and toxic elements were measured by electrothermal atomic absorption spectroscopy after microwave-assisted acid digestion. The validity and accuracy of methodology was checked by using certified reference materials (CRMs) and the conventional wet acid digestion method on the same CRMs and real samples. Results: The observed mean values of As were significantly higher in scalp hair, blood, and urine samples of patients with mild and severe psoriasis as compared to the controls (p = 0.01 - 0.001), while the concentrations of Se were lower in the scalp hair and blood, but higher in the urine samples of psoriasis patients of all categories. Conclusions: The deficiency of Se in psoriatic patients may undoubtedly be caused by the toxic element exposures via dust produced by the cement factory.

Research paper thumbnail of Microwave-assisted acid extraction of selenium from medicinal plants followed by electrothermal atomic absorption spectrometric determination

Journal of AOAC International

A simple and rapid microwave-assisted extraction (MAE) of selenium (Se) from medicinal plants was... more A simple and rapid microwave-assisted extraction (MAE) of selenium (Se) from medicinal plants was investigated using different concentrations of nitric acid and hydrochloric acid, sample mass, heating time, microwave energy, and plant particle size. The optimization strategy was carried out using multivariate methodologies. Electrothermal atomic absorption spectrometry was used to determine Se. The accuracy of the optimized procedure was evaluated by using certified reference materials with certified values for Se and a microwave-assisted acid digestion (MD) method for comparative purpose. No significant difference was observed (P > 0.05) when comparing the values obtained by the proposed MAE and MD methods (paired t-test). Under the optimum operating conditions, the LOD obtained from the standard calibration curve was 0.012 microg/L for Se. The average RSD of the MAE method varied between 4.05 and 7.53% (n = 6). The proposed method was successfully applied for the determination ...

Research paper thumbnail of Preconcentration and determination of lead and cadmium levels in blood samples of adolescent workers consuming smokeless tobacco products in Pakistan

Environmental Monitoring and Assessment, 2015

The present study was aimed to evaluate the cadmium (Cd) and lead (Pb) levels in the blood sample... more The present study was aimed to evaluate the cadmium (Cd) and lead (Pb) levels in the blood samples of adolescent boys, chewing different smokeless tobacco (SLT) products in Pakistan. For comparative purpose, boys of the same age group (12-15 years), not consumed any SLT products were selected as referents. To determine trace levels of Cd and Pb in blood samples, a preconcentration method, vortex-assisted liquid-liquid microextraction (VLLME) has been developed, prior to analysis by flame atomic absorption spectrometry. The hydrophobic chelates of Cd and Pb with ammonium pyrrolidinedithiocarbamate were extracted into the fine droplets of ionic liquid (IL) 1-butyl-3-methylimidazolium hexafluorophosphate, while nonionic surfactant, Triton X-114 was used as a dispersing medium. The main factors affecting the recoveries of Cd and Pb, such as concentration of APDC, centrifugation time, volume of IL and TX-114, were investigated in detail. It was also observed that adolescent boys who consumed different SLT products have 2- to 3-fold higher levels of Cd and Pb in their blood samples as compared to referent boys (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001).

Research paper thumbnail of Evaluation of arsenic, cadmium, lead, nickel, and zinc in biological samples (scalp hair, blood, and urine) of tuberculosis and diarrhea male human immunodeficiency virus patients

Clinical laboratory, 2011

The consequence of a deficiency in trace elements has been associated with an increased risk of h... more The consequence of a deficiency in trace elements has been associated with an increased risk of human immunodeficiency virus type 1 (HIV-1) disease progression and mortality. This study examined the association between high scalp hair and blood arsenic, cadmium, lead, and nickel concentrations and opportunistic infections in hospitalized patients with the acquired immune deficiency syndrome (AIDS). The study was performed on sixty two male HIV+ patients (HIV-1) from different cities of Pakistan. The patients were divided in two groups according to secondary infections (tuberculosis, diarrhea, and high fever). The biological samples (scalp hair, blood, and urine) were collected from AIDS patients, and for comparative study 120 healthy subjects (males) of same age group (31 - 45 years), socio-economic status, localities, and dietary habits were also included. The elements in the biological samples were analyzed by electrothermal atomic absorption spectrophotometry, prior to microwave-...

Research paper thumbnail of Evaluation of zinc, copper and iron in biological samples (scalp hair, blood and urine) of tuberculosis and diarrhea male human immunodeficiency virus patients

Clinical laboratory, 2011

The consequence of a deficiency in trace elements has been associated with an increased risk of h... more The consequence of a deficiency in trace elements has been associated with an increased risk of human immunodeficiency virus type 1 (HIV-1) disease progression and mortality. This study examined the association between low scalp hair and blood zinc, copper, and iron concentrations and opportunistic infections in hospitalized patients with the acquired immune deficiency syndrome (AIDS). The study was performed on sixty two male HIV+ patients (HIV-1) from different cities in Pakistan. The patients were divided in two groups according to secondary infections (tuberculosis, diarrhea and high fever). The biological samples (scalp hair, blood, and urine) were collected from AIDS patients. For comparative study, 120 healthy subjects (males) of the same age group (31 - 45 years), socio-economic status, localities, and dietary habits were also included. The elements in the biological samples were analyzed by flame atomic absorption spectrophotometry prior to microwave-assisted acid digestion...

Research paper thumbnail of Evaluation of status of calcium, magnesium, potassium, and sodium levels in biological samples in children of different age groups with normal vision and night blindness

Clinical laboratory, 2011

The most common cause of blindness in developing countries is vitamin A deficiency. The World Hea... more The most common cause of blindness in developing countries is vitamin A deficiency. The World Health Organization (WHO) estimates 13.8 million children have some degree of visual loss related to vitamin A deficiency. The causes of night blindness in children are multifactorial and particular consideration has been given to childhood nutritional deficiency, which is the most common problem found in underdeveloped countries. Such deficiency can result in physiological and pathological processes that in turn influence biological sample composition. Vitamin and mineral deficiency prevents more than two billion people from achieving their full intellectual and physical potential. This study was designed to compare the levels of magnesium (Mg), calcium (Ca), potassium (K), and sodium (Na) in scalp hair, serum, blood, and urine of night blindness children in two age groups, (1-5) and (6-10) years, of both genders comparing them to sex- and age-matched controls. A microwave assisted wet aci...

Research paper thumbnail of Determination of arsenic in scalp hair samples from exposed subjects using microwave-assisted digestion with and without enrichment based on cloud point extraction by electrothermal atomic absorption spectrometry

Journal of AOAC International

A simple and rapid cloud point extraction (CPE) procedure was applied for preconcentration of tra... more A simple and rapid cloud point extraction (CPE) procedure was applied for preconcentration of trace quantities of arsenic (As) in scalp hair samples. The samples were subjected to microwave-assisted digestion in a mixture of nitric acid and hydrogen peroxide (2 + 1, v/v) prior to preconcentration by CPE. The As in digested samples was complexed with ammonium pyrrolidine dithiocarbamate (APDC), and the resultant As-PDC complex was extracted by a nonionic surfactant, octylphenoxypolyethoxyethanol (Triton X-114). After centrifugation, the surfactant-rich phase was diluted with 0.1 M HNO3 in methanol and analyzed by electrothermal atomic absorption spectrometry. The experimental parameters, i.e., amount of APDC, concentration of Triton X-114, equilibrium temperature and time, were optimized. For validation of the proposed method, a certified reference material (CRM) of human hair (BCR 397) was used. No significant difference (P > 0.05) was observed between the experimental results an...

Research paper thumbnail of A green and efficient in-syringe ionic liquid-based single step microextraction procedure for preconcentration and determination of cadmium in water samples

Journal of Industrial and Engineering Chemistry, 2015

ABSTRACT An in-syringe ionic liquid-based single step microextraction has been analytically prese... more ABSTRACT An in-syringe ionic liquid-based single step microextraction has been analytically presented. 1-butyl-3-methylimidazolium hexafluorophosphate as extractant and Triton X-100 as dispersing medium were used. Cd-Dithizone was extracted within a syringe. The effects of some variables such as [C4mim][PF6] volume, pH, TX-100 volume, dithizone concentration, incubation time, diluents nature and matrix effect were investigated. The limit of detection and preconcentration factor were found as 0.35 μg L−1 and 50, respectively. The validity was checked by using certified reference materials. The relative standard deviation (RSD) was 4.2%. The method was satisfactorily applied to preconcentration of cadmium in natural water samples.

Research paper thumbnail of Room Temperature Ionic Liquid-Based Dispersive Liquid Phase Microextraction for the Separation/Preconcentration of Trace Cd2+ as 1-(2-pyridylazo)-2-naphthol (PAN) Complex from Environmental and Biological Samples and Determined by FAAS

Biological Trace Element Research, 2013

The current work develops a new green methodology for the separation/preconcentration of cadmium ... more The current work develops a new green methodology for the separation/preconcentration of cadmium ions (Cd(2+)) using room temperature ionic liquid-dispersive liquid phase microextraction (RTIL-DLME) prior to analysis by flame atomic absorption spectrometry with microsample introduction system. Room temperature ionic liquids (RTIL) are considered &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;Green Solvents&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; for their thermally stable and non-volatile properties, here 1-butyl-3-methylimidazolium hexafluorophosphate [C4mim][PF6] was used as an extractant. The preconcentration of Cd(2+) in different waters and acid digested scalp hair samples were complexed with 1-(2-pyridylazo)-2-naphthol and extracted into the fine drops of RTILs. Some significant factors influencing the extraction efficiency of Cd(2+) and its subsequent determination, including pH, amount of ligand, volume of RTIL, dispersant solvent, sample volume, temperature, and incubation time were investigated in detail. The limit of detection and the enhancement factor under the optimal conditions were 0.05 μg/L and 50, respectively. The relative standard deviation of 100 μg/L Cd(2+) was 4.3 %. The validity of the proposed method was checked by determining Cd(2+) in certified reference material (TM-25.3 fortified water). The sufficient recovery (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;98 %) of Cd(2+) with the certified value. The mean concentrations of Cd in lake water 13.2, waste water 15.7 and hair sample 16.8 μg/L, respectively and the developed method was applied satisfactorily to the preconcentration and determination of Cd(2+) in real samples.

Research paper thumbnail of Determination of Arsenic in Scalp Hair of Children and its Correlation with Drinking Water in Exposed Areas of Sindh Pakistan

Biological Trace Element Research, 2010

This study was focused on the analysis of arsenic (As) levels in scalp hair of children (age, <10... more This study was focused on the analysis of arsenic (As) levels in scalp hair of children (age, <10 years) collected from two towns of Khairpur, Pakistan, to evaluate the effects of As-contaminated groundwater. For comparative purposes, scalp hair samples of children were also collected from that area having low levels of As (<10 μg/L) in drinking water. Groundwater and scalp hair samples of children were collected and analyzed by electrothermal atomic absorption spectrometry prior to microwave-assisted acid digestion. The average As concentrations in groundwater samples of two towns, Thari Mirwah and Gambat, were found to be 28.5 and 98.3 μg/L, respectively. The range of As concentrations in scalp hair samples of children who belong to Thari Mirwah and Gambat was 1.25-1.61 μg/g and 1.73-3.63 μg/g, respectively. Twenty percent of the total children who belong to Gambat have skin lesions on their hands and feet. A positive correlation coefficient (R=0.91-0.99) was obtained between As contents in drinking water and scalp hairs of children of both towns.