Saeed Albaseer - Academia.edu (original) (raw)
Papers by Saeed Albaseer
Science of the total environment, Jun 1, 2024
Water
In this study, the use of linear alkylbenzenes (LABs) was employed to pinpoint the sources of hum... more In this study, the use of linear alkylbenzenes (LABs) was employed to pinpoint the sources of human activity that cause detrimental impacts on the coastal environment and river ecosystems. LABs were detected using GC–MS in sediment samples assembled from Kim Kim River (KKR) and the Port Dickson coast (PDC). To assess the significance of variations in the distribution and concentrations of LABs across the sampling sites, this study utilized several statistical techniques such as post hoc tests, LSD techniques, analysis of variance (ANOVA), and the Pearson correlation coefficient using a significance level of p < 0.05. The degradation levels of LABs and wastewater treatment were assessed in the study using internal congeners (I/E), homologs of C13 and C12, and long-to-short-chain (L/S) ratios. The results revealed that the LAB concentrations varied between 88.3 and 112 ng/g dw in KKR and 119 to 256 ng/g dw in the PDC. Most of the surveyed areas exhibited a substantial count of C13–...
International Journal of Environment, Jan 9, 2018
Chemical and statistical regression analysis on groundwater at five fields (17 sampling wells) lo... more Chemical and statistical regression analysis on groundwater at five fields (17 sampling wells) located in Dhamar city, the central highlands of Yemen, was carried out. Samples were collected from the ground water supplies (tube wells) during the year 2015. Physical parameters studied include (values between bracket s represents the measured mean values) temperature (T, 25°), total dissolved solids (TDS, 271.47), pH (7.5), and electrical conductivity (EC, 424.18). The chemical parameters investigated include total hardness (TH, 127.45), calcium (Ca 2+ , 32.89), magnesium (Mg 2+ , 11.03), bicarbonate (HCO3 , 143.84), sulphate (SO 4 2-, 143.84), sodium (Na + , 35.11), potassium (K + , 6.28) and Chloride (Cl , 22.69). The results were compared with drinking water quality standards issued by Yemen standards for drinking water. Except for T° and pH, all other measured parameters fall below the minimum permissible limits. The correlation between various physio-chemical parameters of the studied water wells was performed using Principal Component Analysis (PCA) method. The obtained results show that all water samples are potable and can be safely used for both drinking and irrigation purposes. This comes in agreement with the public notion about groundwater of Dhamar Governorate. Sodium Absorption Ratio (SAR) values were calculated and found below 3 except for one drill. The results revealed that systematic calculations of correlation coefficients between water parameters and regression analysis provide a useful means for rapid monitoring of water quality.
LAP LAMBERT Academic Publishing eBooks, Aug 31, 2012
ABSTRACT Synthetic pyrethroids are a class of pesticides widely used for agricultural and househo... more ABSTRACT Synthetic pyrethroids are a class of pesticides widely used for agricultural and household purposes. The use of synthetic pyrethroids has, considerably, increased in recent years. However, the increase in synthetic pyrethroids use has subsequently raised concerns about their effect on aquatic life as they are highly toxic to aquatic invertebrates. Thus, monitoring accumulation of these compounds in the environmental matrices is of great concern. In this book the analytical methods for the analysis of pyrethroids were compared with detailed discussion about their merits and demerits. Also, factors affecting stability of synthetic pyrethroids in environmental samples were discussed. Besides, on the basis of published literature and my experience, suggestions were made concerning the optimum conditions for handling environmental samples of synthetic pyrethroids during transport and storage. Finally, I hope that this book will benefit researchers in the field of environmental analysis.
Analytical Methods, 2014
ABSTRACT The phenomena of selective adsorption of synthetic pyrethroids on polytetrafluoroethylen... more ABSTRACT The phenomena of selective adsorption of synthetic pyrethroids on polytetrafluoroethylene containers observed while storing contaminated water samples, has been reversibly exploited for quantitative solid phase extraction followed by their determination by RP-HPLC. A specially designed glass column packed with very fine pellets of polytetrafluoroethylene was used as a SPE cartridge and factors affecting adsorption/desorption processes were optimized. High enrichment factors ranging 1882–3318 were obtained with detection limits as low as 0.03–0.06 ng mL−1. When compared with the conventional C18-based SPE, it showed good selectivity against highly and moderately polar organic compounds making it superior to C18 SPE particularly for extraction of synthetic pyrethroids from complex aqueous media. This is the first report on the use of polytetrafluoroethylene as SPE adsorbent for selective extraction and quantitative determination of synthetic pyrethroids from contaminated surface waters.
Toxicological & Environmental Chemistry, Aug 1, 2011
A micro liquidliquid extraction (MLLE) flask designed for the extraction of bioavailable synthet... more A micro liquidliquid extraction (MLLE) flask designed for the extraction of bioavailable synthetic pyrethroids from agricultural and ground water samples is used. The method is simple, rapid, and reproducible. Extracts are analyzed off-line by reversed-phase high-...
Journal of Taibah University for Science, 2016
The present study reports the characterization of four degradation products from ezetemibe (EZB) ... more The present study reports the characterization of four degradation products from ezetemibe (EZB) through liquid chromatography-tandem mass spectrometry (LC-MS/MS) and the development of a validated and stability-indicating reversedphase ultra-performance liquid chromatographic method for the determination of EZB in the presence of its process-related impurities in bulk drugs. The forced decomposition of EZB was carried out and studied under acidic, basic, oxidative, photolytic and thermal conditions. The degradation of EZB was observed under basic and acidic conditions, and four degradation products (DPs) were formed. Successful chromatographic separation of EZB and its degradation products were successfully separated through chromatography with a Waters Acquity HSST3 C18 stationary phase (50 × 2.1 mm, 1.7 m). The analytes were detected with a PDA detector set at 230 nm. The figures of merit for this method were adequate. The assay remained linear from concentrations of 0.09 g mL −1 to 600 g mL −1 for EZB and its four DPs (r 2 = 0.99914, 0.99945, 0.99917, 0.99923 and 0.99936 for EZB, Imp-A, Imp-B, Imp-C, and Imp-D, respectively). The method precision, which was expressed as the %RSD, ranged from 0.2 to 1.0 for the four impurities. The DPs from EZB were characterized by LC-MS/MS, and the most likely degradation and fragmentation pathways for EZB and its DPs were proposed.
Ecotoxicology and Environmental Safety, Apr 1, 2023
Journal of Analytical Science and Technology, Mar 31, 2012
A novel approach for dispersive liquid-liquid microextraction based on the use of deep eutectic s... more A novel approach for dispersive liquid-liquid microextraction based on the use of deep eutectic solvent as a disperser was presented for the first time. The procedure was automated based on an in-syringe flow system coupled with UV-Vis detection and demonstrated by the determination of chromium (VI) in beverages. This analytical task was used as a proof-of-concept example. The automated extraction procedure involved the aspiration of aqueous sample into a syringe pump with homogeneous mixture of extraction solvent (1-oсtanol) and deep eutectic solvent (tetrabutylammonium bromide-formic acid) containing color-forming reagent (1,5-diphenylcarbazide). This led to decomposition of deep eutectic solvent in aqueous phase resulting in dispersion of extraction solvent, oxidation of 1,5-diphenylcarbazide to 1,5-diphenylcarbazone in the presence of chromium (VI), and formation of colored chromium (III) complex with 1,5-diphenylcarbazone and its fast extraction. In this case composition of deep eutectic solvent played a key role for analyte extraction. Tetrabutylammonium bromide promoted mass transfer between aqueous phase and the extraction solvent droplets as a salting out agent, bromide ion acted as an ion-pare agent for analyte complex extraction, formic acid provided required pH value for analyte complex formation. Under the optimal conditions the limit of detection, calculated from a blank test based on 3s, was 0.2 μg L −1. The automated dispersive liquid-liquid microextraction using deep eutectic solvent as disperser can be considered as an available, efficient, rapid and environmentally friendly sample pretreatment approach.
Elsevier eBooks, 2018
Abstract The recent developments in the use of nanomaterials (NMs) as sorbent substrates for the ... more Abstract The recent developments in the use of nanomaterials (NMs) as sorbent substrates for the extraction and enrichment of trace chemicals from various matrices prior to their chromatographic determinations are described in this chapter. Several classes and forms of nanomaterials are been discussed in terms of their usability, advantages, and shortcomings. The nanomaterials discussed were classified based on the structure and/or chemical compositions of the final form of the materials used as sorbents. The effects of the physicochemical properties of nanomaterials on their efficiency as sorbents, and possibility of controlling them through structural design, modification of surface area, and incorporation of suitable components for improved performance are highlighted. Future perspectives for the application of nanomaterials in chromatographic sample preparations are outlined.
Trends in Analytical Chemistry, Dec 1, 2011
ABSTRACT Sample handling and preservation methods of environmental samples of synthetic pyrethroi... more ABSTRACT Sample handling and preservation methods of environmental samples of synthetic pyrethroids (SPs) are very important and must be controlled to maintain sample integrity during analytical determinations. However, published literature has treated this issue only partly, and, in many instances, with contradictory conclusions. The tendency of SPs to adsorb – to varying degrees under different conditions – to surfaces and solid particulates with which they come in contact may be responsible for this situation. It has become evident that SPs discharged to water bodies are present mainly in the adsorbed state, and that affects their bioavailability and the reliability of analytical results. Refrigeration and storage in the dark are prerequisites for stabilization of SPs in environmental samples. Several other factors that contribute to SPs instability include: (1) matrix composition; (2) container material; and, (3) sample acidity. Sample agitation prior to analysis may be useful to reduce losses due to adsorption. There are several chemical reagents that inhibit the degradative processes of SPs, but the efficiency of preservation depends – to a large extent – on the characteristics of sample matrix. This article reviews various aspects related to preservation of SPs and puts forward a preliminary guideline for proper practice during sampling, storage and sample preparation of SPs.
Journal of Chromatography A, Aug 1, 2010
The latest developments in sample preparation and extraction of synthetic pyrethroids from enviro... more The latest developments in sample preparation and extraction of synthetic pyrethroids from environmental matrices viz., water, sediment and soil were reviewed. Though the synthetic pyrethroids were launched in 1970s, to the best of authors' knowledge there was no review on this subject until date. The present status and recent advances made during the last 10 years in sample preparation including conservation and extraction techniques used in determination of synthetic pyrethroids in water, sediment and soil were discussed. Pre-and post-extraction treatments, sample stability during extraction and its influence upon the whole process of analytical determination were covered. Relative merits and demerits including the green aspects of extraction were evaluated. The current trends and future prospects were also addressed.
International Journal of Pharmacy, Apr 20, 2016
A solid phase extraction method was developed for the simultaneous quantification of risperidone ... more A solid phase extraction method was developed for the simultaneous quantification of risperidone and escitalopram in human plasma by a suitable ultra-performance liquid chromatographic / tandem mass spectrometric..
Analytical chemistry, an Indian journal, 2014
ABSTRACT The choice of a sample preparation method is not an easy task, as many aspects should be... more ABSTRACT The choice of a sample preparation method is not an easy task, as many aspects should be accounted for. These aspects are either related to the analyte(s) of interest or the method and its compatibility with the sample matrix. Several methods, however, can be applied for the extraction of pyrethroids from aqueous samples but none is free of drawbacks. In this paper, three recently developed principles for the extraction of synthetic pyrethroids from aqueous samples have been practically and statistically evaluated. Merits and demerits have been discussed. It has been found that the method extraction capability is not the solely characteristic that should be looked at when choosing an extraction method. Other characteristics such as method detection limits, sample preparation time, and stability of the analytes in the extracting phase are also important. Pyrethroids are very hydrophobic and adsorb strongly onto walls of devices used for extraction and, hence, the kind of extraction vessel material is important.
Research Square (Research Square), Jul 8, 2022
Determination of the ethanol content in non-alcoholic beverages is driven by health concerns and ... more Determination of the ethanol content in non-alcoholic beverages is driven by health concerns and is often imposed by regulating agencies. In this paper, we present the development of a simple and sensitive HPLC method for the determination of ethanol in Juices and beverages. Ethanol undergoes precolumn derivatization using 9-Fluorenylmethyl chloroformate (Fmoc-Cl). The resulting derivative has the property that it can be detected using both UV and uorescence detectors, which makes ethanol quanti cation in complex matrices more accessible. LOD and LOQ were 0.004 g/L and 0.01 g/L %, for uorescence detector, and 0.15 g/L and 0.5 g/L, for UV detector, respectively. The mean recovery ranged from 98-109% with a relative standard deviation (RSD%) of 3.7%. This approach to ethanol determination is novel and the method is so sensitive that only a 100 µL sample volume is required and the reaction product (derivative) can be directly injected without extraction or pre-concentration. The resulting derivative has the property that it can be detected using both UV and uorescence. Ethanol is usually determined by GC, thus, the present method serves as an alternative to current GC methods.
Analytical Chemistry Letters, Nov 1, 2020
The present study reports the characterization of four degradation products from ezetemibe (EZB) ... more The present study reports the characterization of four degradation products from ezetemibe (EZB) through liquid chromatography-tandem mass spectrometry (LC-MS/MS) and the development of a validated and stability-indicating reversedphase ultra-performance liquid chromatographic method for the determination of EZB in the presence of its process-related impurities in bulk drugs. The forced decomposition of EZB was carried out and studied under acidic, basic, oxidative, photolytic and thermal conditions. The degradation of EZB was observed under basic and acidic conditions, and four degradation products (DPs) were formed. Successful chromatographic separation of EZB and its degradation products were successfully separated through chromatography with a Waters Acquity HSST3 C18 stationary phase (50 × 2.1 mm, 1.7 m). The analytes were detected with a PDA detector set at 230 nm. The figures of merit for this method were adequate. The assay remained linear from concentrations of 0.09 g mL −1 to 600 g mL −1 for EZB and its four DPs (r 2 = 0.99914, 0.99945, 0.99917, 0.99923 and 0.99936 for EZB, Imp-A, Imp-B, Imp-C, and Imp-D, respectively). The method precision, which was expressed as the %RSD, ranged from 0.2 to 1.0 for the four impurities. The DPs from EZB were characterized by LC-MS/MS, and the most likely degradation and fragmentation pathways for EZB and its DPs were proposed.
Determination of the ethanol content in non-alcoholic beverages is driven by health concerns and ... more Determination of the ethanol content in non-alcoholic beverages is driven by health concerns and is often imposed by regulating agencies. In this paper, we present the development of a simple and sensitive HPLC method for the determination of ethanol in Juices and beverages. Ethanol undergoes precolumn derivatization using 9-Fluorenylmethyl chloroformate (Fmoc-Cl). The resulting derivative has the property that it can be detected using both UV and fluorescence detectors, which makes ethanol quantification in complex matrices more accessible. LOD and LOQ were 0.004 g/L and 0.01 g/L %, for fluorescence detector, and 0.15 g/L and 0.5 g/L, for UV detector, respectively. The mean recovery ranged from 98–109% with a relative standard deviation (RSD%) of 3.7%. This approach to ethanol determination is novel and the method is so sensitive that only a 100 µL sample volume is required and the reaction product (derivative) can be directly injected without extraction or pre-concentration. The r...
Science of the total environment, Jun 1, 2024
Water
In this study, the use of linear alkylbenzenes (LABs) was employed to pinpoint the sources of hum... more In this study, the use of linear alkylbenzenes (LABs) was employed to pinpoint the sources of human activity that cause detrimental impacts on the coastal environment and river ecosystems. LABs were detected using GC–MS in sediment samples assembled from Kim Kim River (KKR) and the Port Dickson coast (PDC). To assess the significance of variations in the distribution and concentrations of LABs across the sampling sites, this study utilized several statistical techniques such as post hoc tests, LSD techniques, analysis of variance (ANOVA), and the Pearson correlation coefficient using a significance level of p < 0.05. The degradation levels of LABs and wastewater treatment were assessed in the study using internal congeners (I/E), homologs of C13 and C12, and long-to-short-chain (L/S) ratios. The results revealed that the LAB concentrations varied between 88.3 and 112 ng/g dw in KKR and 119 to 256 ng/g dw in the PDC. Most of the surveyed areas exhibited a substantial count of C13–...
International Journal of Environment, Jan 9, 2018
Chemical and statistical regression analysis on groundwater at five fields (17 sampling wells) lo... more Chemical and statistical regression analysis on groundwater at five fields (17 sampling wells) located in Dhamar city, the central highlands of Yemen, was carried out. Samples were collected from the ground water supplies (tube wells) during the year 2015. Physical parameters studied include (values between bracket s represents the measured mean values) temperature (T, 25°), total dissolved solids (TDS, 271.47), pH (7.5), and electrical conductivity (EC, 424.18). The chemical parameters investigated include total hardness (TH, 127.45), calcium (Ca 2+ , 32.89), magnesium (Mg 2+ , 11.03), bicarbonate (HCO3 , 143.84), sulphate (SO 4 2-, 143.84), sodium (Na + , 35.11), potassium (K + , 6.28) and Chloride (Cl , 22.69). The results were compared with drinking water quality standards issued by Yemen standards for drinking water. Except for T° and pH, all other measured parameters fall below the minimum permissible limits. The correlation between various physio-chemical parameters of the studied water wells was performed using Principal Component Analysis (PCA) method. The obtained results show that all water samples are potable and can be safely used for both drinking and irrigation purposes. This comes in agreement with the public notion about groundwater of Dhamar Governorate. Sodium Absorption Ratio (SAR) values were calculated and found below 3 except for one drill. The results revealed that systematic calculations of correlation coefficients between water parameters and regression analysis provide a useful means for rapid monitoring of water quality.
LAP LAMBERT Academic Publishing eBooks, Aug 31, 2012
ABSTRACT Synthetic pyrethroids are a class of pesticides widely used for agricultural and househo... more ABSTRACT Synthetic pyrethroids are a class of pesticides widely used for agricultural and household purposes. The use of synthetic pyrethroids has, considerably, increased in recent years. However, the increase in synthetic pyrethroids use has subsequently raised concerns about their effect on aquatic life as they are highly toxic to aquatic invertebrates. Thus, monitoring accumulation of these compounds in the environmental matrices is of great concern. In this book the analytical methods for the analysis of pyrethroids were compared with detailed discussion about their merits and demerits. Also, factors affecting stability of synthetic pyrethroids in environmental samples were discussed. Besides, on the basis of published literature and my experience, suggestions were made concerning the optimum conditions for handling environmental samples of synthetic pyrethroids during transport and storage. Finally, I hope that this book will benefit researchers in the field of environmental analysis.
Analytical Methods, 2014
ABSTRACT The phenomena of selective adsorption of synthetic pyrethroids on polytetrafluoroethylen... more ABSTRACT The phenomena of selective adsorption of synthetic pyrethroids on polytetrafluoroethylene containers observed while storing contaminated water samples, has been reversibly exploited for quantitative solid phase extraction followed by their determination by RP-HPLC. A specially designed glass column packed with very fine pellets of polytetrafluoroethylene was used as a SPE cartridge and factors affecting adsorption/desorption processes were optimized. High enrichment factors ranging 1882–3318 were obtained with detection limits as low as 0.03–0.06 ng mL−1. When compared with the conventional C18-based SPE, it showed good selectivity against highly and moderately polar organic compounds making it superior to C18 SPE particularly for extraction of synthetic pyrethroids from complex aqueous media. This is the first report on the use of polytetrafluoroethylene as SPE adsorbent for selective extraction and quantitative determination of synthetic pyrethroids from contaminated surface waters.
Toxicological & Environmental Chemistry, Aug 1, 2011
A micro liquidliquid extraction (MLLE) flask designed for the extraction of bioavailable synthet... more A micro liquidliquid extraction (MLLE) flask designed for the extraction of bioavailable synthetic pyrethroids from agricultural and ground water samples is used. The method is simple, rapid, and reproducible. Extracts are analyzed off-line by reversed-phase high-...
Journal of Taibah University for Science, 2016
The present study reports the characterization of four degradation products from ezetemibe (EZB) ... more The present study reports the characterization of four degradation products from ezetemibe (EZB) through liquid chromatography-tandem mass spectrometry (LC-MS/MS) and the development of a validated and stability-indicating reversedphase ultra-performance liquid chromatographic method for the determination of EZB in the presence of its process-related impurities in bulk drugs. The forced decomposition of EZB was carried out and studied under acidic, basic, oxidative, photolytic and thermal conditions. The degradation of EZB was observed under basic and acidic conditions, and four degradation products (DPs) were formed. Successful chromatographic separation of EZB and its degradation products were successfully separated through chromatography with a Waters Acquity HSST3 C18 stationary phase (50 × 2.1 mm, 1.7 m). The analytes were detected with a PDA detector set at 230 nm. The figures of merit for this method were adequate. The assay remained linear from concentrations of 0.09 g mL −1 to 600 g mL −1 for EZB and its four DPs (r 2 = 0.99914, 0.99945, 0.99917, 0.99923 and 0.99936 for EZB, Imp-A, Imp-B, Imp-C, and Imp-D, respectively). The method precision, which was expressed as the %RSD, ranged from 0.2 to 1.0 for the four impurities. The DPs from EZB were characterized by LC-MS/MS, and the most likely degradation and fragmentation pathways for EZB and its DPs were proposed.
Ecotoxicology and Environmental Safety, Apr 1, 2023
Journal of Analytical Science and Technology, Mar 31, 2012
A novel approach for dispersive liquid-liquid microextraction based on the use of deep eutectic s... more A novel approach for dispersive liquid-liquid microextraction based on the use of deep eutectic solvent as a disperser was presented for the first time. The procedure was automated based on an in-syringe flow system coupled with UV-Vis detection and demonstrated by the determination of chromium (VI) in beverages. This analytical task was used as a proof-of-concept example. The automated extraction procedure involved the aspiration of aqueous sample into a syringe pump with homogeneous mixture of extraction solvent (1-oсtanol) and deep eutectic solvent (tetrabutylammonium bromide-formic acid) containing color-forming reagent (1,5-diphenylcarbazide). This led to decomposition of deep eutectic solvent in aqueous phase resulting in dispersion of extraction solvent, oxidation of 1,5-diphenylcarbazide to 1,5-diphenylcarbazone in the presence of chromium (VI), and formation of colored chromium (III) complex with 1,5-diphenylcarbazone and its fast extraction. In this case composition of deep eutectic solvent played a key role for analyte extraction. Tetrabutylammonium bromide promoted mass transfer between aqueous phase and the extraction solvent droplets as a salting out agent, bromide ion acted as an ion-pare agent for analyte complex extraction, formic acid provided required pH value for analyte complex formation. Under the optimal conditions the limit of detection, calculated from a blank test based on 3s, was 0.2 μg L −1. The automated dispersive liquid-liquid microextraction using deep eutectic solvent as disperser can be considered as an available, efficient, rapid and environmentally friendly sample pretreatment approach.
Elsevier eBooks, 2018
Abstract The recent developments in the use of nanomaterials (NMs) as sorbent substrates for the ... more Abstract The recent developments in the use of nanomaterials (NMs) as sorbent substrates for the extraction and enrichment of trace chemicals from various matrices prior to their chromatographic determinations are described in this chapter. Several classes and forms of nanomaterials are been discussed in terms of their usability, advantages, and shortcomings. The nanomaterials discussed were classified based on the structure and/or chemical compositions of the final form of the materials used as sorbents. The effects of the physicochemical properties of nanomaterials on their efficiency as sorbents, and possibility of controlling them through structural design, modification of surface area, and incorporation of suitable components for improved performance are highlighted. Future perspectives for the application of nanomaterials in chromatographic sample preparations are outlined.
Trends in Analytical Chemistry, Dec 1, 2011
ABSTRACT Sample handling and preservation methods of environmental samples of synthetic pyrethroi... more ABSTRACT Sample handling and preservation methods of environmental samples of synthetic pyrethroids (SPs) are very important and must be controlled to maintain sample integrity during analytical determinations. However, published literature has treated this issue only partly, and, in many instances, with contradictory conclusions. The tendency of SPs to adsorb – to varying degrees under different conditions – to surfaces and solid particulates with which they come in contact may be responsible for this situation. It has become evident that SPs discharged to water bodies are present mainly in the adsorbed state, and that affects their bioavailability and the reliability of analytical results. Refrigeration and storage in the dark are prerequisites for stabilization of SPs in environmental samples. Several other factors that contribute to SPs instability include: (1) matrix composition; (2) container material; and, (3) sample acidity. Sample agitation prior to analysis may be useful to reduce losses due to adsorption. There are several chemical reagents that inhibit the degradative processes of SPs, but the efficiency of preservation depends – to a large extent – on the characteristics of sample matrix. This article reviews various aspects related to preservation of SPs and puts forward a preliminary guideline for proper practice during sampling, storage and sample preparation of SPs.
Journal of Chromatography A, Aug 1, 2010
The latest developments in sample preparation and extraction of synthetic pyrethroids from enviro... more The latest developments in sample preparation and extraction of synthetic pyrethroids from environmental matrices viz., water, sediment and soil were reviewed. Though the synthetic pyrethroids were launched in 1970s, to the best of authors' knowledge there was no review on this subject until date. The present status and recent advances made during the last 10 years in sample preparation including conservation and extraction techniques used in determination of synthetic pyrethroids in water, sediment and soil were discussed. Pre-and post-extraction treatments, sample stability during extraction and its influence upon the whole process of analytical determination were covered. Relative merits and demerits including the green aspects of extraction were evaluated. The current trends and future prospects were also addressed.
International Journal of Pharmacy, Apr 20, 2016
A solid phase extraction method was developed for the simultaneous quantification of risperidone ... more A solid phase extraction method was developed for the simultaneous quantification of risperidone and escitalopram in human plasma by a suitable ultra-performance liquid chromatographic / tandem mass spectrometric..
Analytical chemistry, an Indian journal, 2014
ABSTRACT The choice of a sample preparation method is not an easy task, as many aspects should be... more ABSTRACT The choice of a sample preparation method is not an easy task, as many aspects should be accounted for. These aspects are either related to the analyte(s) of interest or the method and its compatibility with the sample matrix. Several methods, however, can be applied for the extraction of pyrethroids from aqueous samples but none is free of drawbacks. In this paper, three recently developed principles for the extraction of synthetic pyrethroids from aqueous samples have been practically and statistically evaluated. Merits and demerits have been discussed. It has been found that the method extraction capability is not the solely characteristic that should be looked at when choosing an extraction method. Other characteristics such as method detection limits, sample preparation time, and stability of the analytes in the extracting phase are also important. Pyrethroids are very hydrophobic and adsorb strongly onto walls of devices used for extraction and, hence, the kind of extraction vessel material is important.
Research Square (Research Square), Jul 8, 2022
Determination of the ethanol content in non-alcoholic beverages is driven by health concerns and ... more Determination of the ethanol content in non-alcoholic beverages is driven by health concerns and is often imposed by regulating agencies. In this paper, we present the development of a simple and sensitive HPLC method for the determination of ethanol in Juices and beverages. Ethanol undergoes precolumn derivatization using 9-Fluorenylmethyl chloroformate (Fmoc-Cl). The resulting derivative has the property that it can be detected using both UV and uorescence detectors, which makes ethanol quanti cation in complex matrices more accessible. LOD and LOQ were 0.004 g/L and 0.01 g/L %, for uorescence detector, and 0.15 g/L and 0.5 g/L, for UV detector, respectively. The mean recovery ranged from 98-109% with a relative standard deviation (RSD%) of 3.7%. This approach to ethanol determination is novel and the method is so sensitive that only a 100 µL sample volume is required and the reaction product (derivative) can be directly injected without extraction or pre-concentration. The resulting derivative has the property that it can be detected using both UV and uorescence. Ethanol is usually determined by GC, thus, the present method serves as an alternative to current GC methods.
Analytical Chemistry Letters, Nov 1, 2020
The present study reports the characterization of four degradation products from ezetemibe (EZB) ... more The present study reports the characterization of four degradation products from ezetemibe (EZB) through liquid chromatography-tandem mass spectrometry (LC-MS/MS) and the development of a validated and stability-indicating reversedphase ultra-performance liquid chromatographic method for the determination of EZB in the presence of its process-related impurities in bulk drugs. The forced decomposition of EZB was carried out and studied under acidic, basic, oxidative, photolytic and thermal conditions. The degradation of EZB was observed under basic and acidic conditions, and four degradation products (DPs) were formed. Successful chromatographic separation of EZB and its degradation products were successfully separated through chromatography with a Waters Acquity HSST3 C18 stationary phase (50 × 2.1 mm, 1.7 m). The analytes were detected with a PDA detector set at 230 nm. The figures of merit for this method were adequate. The assay remained linear from concentrations of 0.09 g mL −1 to 600 g mL −1 for EZB and its four DPs (r 2 = 0.99914, 0.99945, 0.99917, 0.99923 and 0.99936 for EZB, Imp-A, Imp-B, Imp-C, and Imp-D, respectively). The method precision, which was expressed as the %RSD, ranged from 0.2 to 1.0 for the four impurities. The DPs from EZB were characterized by LC-MS/MS, and the most likely degradation and fragmentation pathways for EZB and its DPs were proposed.
Determination of the ethanol content in non-alcoholic beverages is driven by health concerns and ... more Determination of the ethanol content in non-alcoholic beverages is driven by health concerns and is often imposed by regulating agencies. In this paper, we present the development of a simple and sensitive HPLC method for the determination of ethanol in Juices and beverages. Ethanol undergoes precolumn derivatization using 9-Fluorenylmethyl chloroformate (Fmoc-Cl). The resulting derivative has the property that it can be detected using both UV and fluorescence detectors, which makes ethanol quantification in complex matrices more accessible. LOD and LOQ were 0.004 g/L and 0.01 g/L %, for fluorescence detector, and 0.15 g/L and 0.5 g/L, for UV detector, respectively. The mean recovery ranged from 98–109% with a relative standard deviation (RSD%) of 3.7%. This approach to ethanol determination is novel and the method is so sensitive that only a 100 µL sample volume is required and the reaction product (derivative) can be directly injected without extraction or pre-concentration. The r...