Jerzy Mierzwa | Tennessee State University (original) (raw)

Papers by Jerzy Mierzwa

Talanta, Dec 7, 1998

The comparative determination of barium, copper, iron, lead and zinc in tea leaf samples by two a... more The comparative determination of barium, copper, iron, lead and zinc in tea leaf samples by two atomic spectrometric techniques is reported. At first, slurry sampling electrothermal atomization atomic absorption spectrometry (ETAAS) was applied. The results of Ba and Pb determination were calculated using the method of standard additions, and results of Cu, Fe and Zn from the calibration graphs based on aqueous standards. These results were compared with the results obtained after microwave-assisted wet (nitric+hydrochloric+hydrofluoric acids) digestion in closed vessels followed by inductively coupled plasma-atomic emission spectrometric (ICP-AES) determination with the calibration by means of aqueous standards. The exception was lead determined after a wet digestion procedure by ETAAS. The accuracy of the studied methods was checked by the use of the certified reference material Tea GBW-07605. The recoveries of the analytes varied in the range from 91 to 99% for slurry sampling ETAAS, and from 92.5 to 102% for liquid sampling ICP-AES. The advantages of slurry sampling ETAAS method are simplicity of sample preparation and very good sensitivity. Slurry sampling ETAAS method is relatively fast but if several elements must be determined in one sample, the time of the whole microwave-assisted digestion procedure and ICP-AES determination will be shorter. However, worse detection limits of ICP-AES must also be taken into the consideration in a case of some analytes.

Spectrochimica Acta Part B: Atomic Spectroscopy, 1996

... a microwave induced plasma (MIP) operated in a liquidcooled discharge tube for atomic emissio... more ... a microwave induced plasma (MIP) operated in a liquidcooled discharge tube for atomic emission spectrometry J. Mierzwaa'*J, R. BrandP, JAC BroekaerP, P ... intensities of atomic and ionic lines were also reported for other microwave plasma con 40 30 20 lO 120 1 zlO 160 180 ...

Monatshefte Fur Chemie, Feb 1, 1997

The extraction behaviour of Co and Ni chlorides with Aliquat 336-TBP and Aliquat 336-TOPO (Aliqua... more The extraction behaviour of Co and Ni chlorides with Aliquat 336-TBP and Aliquat 336-TOPO (Aliquat 336: tri-n-octylmethylammonium chloride, TBP: tri-n-butylphosphate, TOPO: tri-noctylphosphine oxide) was investigated. The synergistic action of TOPO in the extraction of Co and Ni with Aliquat 336 manifested itself in an increase of the distribution ratio of Co with increasing of TOPO concentration at constant Aliquat 336 concentration without deterioration of the separation factor Co/Ni which still was above 200. Mixed complexes of the general formula MeC12+mAmBn (Me: Co or Ni, A: Aliquat 336, A: TBP or TOPO) with m ranging from 2 to 5 and n from 1 to 3 were present in the organic phase of both systems. The coexistence of several synergistic Co/Ni species in the equilibrium organic phase is reported for the first time.

Journal of The Chinese Chemical Society, Dec 1, 1997

The analytical conditions of the direct determination of bismuth in some certified reference mate... more The analytical conditions of the direct determination of bismuth in some certified reference material samples (soil and sediment) by slurry sampling Zeeman electrothermal atomic absorption spectrometry (ETAAS) with the use of automated ultrasonic slurry mixing are discussed. Palladium nitrate was used as a chemical modifier, WIth the use of this modifier it was possible to stabilize bismuth to the pyrolysis temperature of 1300 •C. Platform atomization was performed at 2050 •C. The results of determination are calculated from a simple, aqueous standards based calibration graph. Statistical evaluation of the results indicate that the slurry sampling method is reproducible and the accuracy of the proposed method is very good. This method is rather simple and its other advantages are good sensitivity and relatively short analysis time.~3

Journal of Analytical Atomic Spectrometry, 1998

ABSTRACT A new analytical procedure for the direct determination of metal impurities in aluminium... more ABSTRACT A new analytical procedure for the direct determination of metal impurities in aluminium oxide by ultrasonic slurry sampling–electrothermal vaporization–inductively coupled plasma mass spectrometry (ETV–ICP-MS) is reported. The elements studied include Cr, Cu, Ga, Fe, Mg, Mn, Na, V and Zn. Two samples of fine alumina powder (including the certified reference material NIST SRM 699) were used in this study without any additional pre-treatment. Analytical results of the external calibration using aqueous standards, the external calibration using matched matrix standards and the standard additions method are presented and compared. The most appropriate (average accuracy of 97±5.5% for sample NIST SRM 699) was the standard additions procedure of calibration. An acceptable agreement was found between the results of the slurry sampling procedure and the certified or reference values, and the repeatability of measurements was always better than 13.6%. Some other analytical figures-of-merit,e.g., limits of detection, are also presented. The absolute limits of detection (for the analysis of 15 µl samples) ranged from 0.8 to 8.3 pg. The speed and multi-element analytical potential of this technique seem to be very advantageous.

Frontiers in Genetics, Jun 24, 2020

Mung bean (Vigna radiata L.) quality is dependent on seed chemical composition, which in turn det... more Mung bean (Vigna radiata L.) quality is dependent on seed chemical composition, which in turn determines the benefits of its consumption for human health and nutrition. While mung bean is rich in a range of nutritional components, such as protein, carbohydrates and vitamins, it remains less well studied than other legume crops in terms of micronutrients. In addition, mung bean genomics and genetic resources are relatively sparse. The objectives of this research were threefold , namely: to develop a genome-wide marker system for mung bean based on genotyping by sequencing (GBS), to evaluate diversity of mung beans available to breeders in the United States and finally, to perform a genome-wide association study (GWAS) for nutrient concentrations based on a seven mineral analysis using inductively coupled plasma (ICP) spectroscopy. All parts of our research were performed with 95 cultivated mung bean genotypes chosen from the USDA core collection representing accessions from 13 countries. Overall, we identified a total of 6,486 high quality single nucleotide polymorphisms (SNPs) from the GBS dataset and found 43 marker × trait associations (MTAs) with calcium, iron, potassium, manganese, phosphorous, sulfur or zinc concentrations in mung bean grain produced in either of two consecutive years' field experiments. The MTAs were scattered across 35 genomic regions explaining on average 22% of the variation for each seed nutrient in each year. Most of the gene regions provided valuable candidate loci to use in future breeding of new varieties of mung bean and further the understanding of genetic control of nutritional properties in the crop. Other SNPs identified in this study will serve as important resources to enable marker-assisted selection (MAS) for nutritional improvement in mung bean and to analyze cultivars of mung bean.

Analytical Letters, 1988

... Words : Emission Spectrogra hic Analysis, Hollow Cathode Discharge, [are Earth Elements, Yttr... more ... Words : Emission Spectrogra hic Analysis, Hollow Cathode Discharge, [are Earth Elements, Yttrium J. Mierzwa Central Laboratory UMCS, 20-031 Lublin, Poland ... Enlargement of inner side surface of the hollow cathode did not lead to increase of rare earth line intensities. ...

Soil systems, Mar 21, 2021

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Analyst, 1992

ABSTRACT A method for the determination of mercury in fluorescent lamp cullet by slurry sampling ... more ABSTRACT A method for the determination of mercury in fluorescent lamp cullet by slurry sampling ETAAS is proposed. Palladium nitrate was applied as an effective matrix modifier. The furnace programme was optimized. The stability of slurries, mercury partitioning between solid and liquid phases for different media and the influence of palladium modifier were investigated. Using the optimized conditions, a detection limit (based on a 3σ criterion) for mercury of 24 ng g–1 was achieved. For 1.55 and 2.16 µg g–1 of mercury in the phosphor sample the RSDs (n= 9) were 8.3 and 8.7%, respectively. Calibration was performed using the standard additions method. The results obtained using this method suggest that the determination of mercury in fluorescent lamp cullet can be carried out effectively and rapidly.

Analytica Chimica Acta, Nov 1, 1997

ABSTRACT

Journal of The Chinese Chemical Society, Dec 1, 1998

A method was developed for the determination of antimony in slurried sediments (on the basis of s... more A method was developed for the determination of antimony in slurried sediments (on the basis of samples of three Certified Reference Materials) by electrothermal atomic absorption spectrometry (ETAAS) with Zeeman-effect background correction. Slurried samples were prepared in 6% nitric acid containing 0.02% of Triton X•IOO. A mixed palladium/magnesium chemical matrix modifier, L'vov platform atomization and a temperature-time program with a relatively short (10 s) sample pyrolysis stage were used. The results of the determinations by this technique are in very close agreement with certified values and the repeatability of this analytical procedure expressed in terms of relative standard deviation was typically better than 9% at the slurry concentration of approx. 90 mgl2 mL. The characteristic mass of Sb (at the spectralline 231.1 nm) was 25.6pg and the limit of detection (calculated for 100 mg/2mL slurry) was about 0.04 Ilg/g•

Analyst, 1996

Talanta, Aug 1, 1997

A new method of efficient rotating gold-film glassy-carbon electrode preparation prior to the det... more A new method of efficient rotating gold-film glassy-carbon electrode preparation prior to the determination of As(III) and As(V) in seawater by anodic stripping voltammetry (ASV) is described. Factors affecting sensitivity and precision including pH, deposition time and potential, rotation and scan rate, and the nature of working electrode were investigated. Electroinactive As(V) was reduced to As(III) by gaseous SO 2 prior to ASV determination. For a deposition time of 4 min the determination limit was approximately 0.19 ppb. Precision of the proposed method was very good (RSD =2-0.6% at 1-5 ppb) and a relatively good accuracy determined by analysis of certified reference seawater (CASS-1) and seawater samples spiked with an arsenic standard solution, was also obtained.

Fresenius Journal of Analytical Chemistry, 1993

Fresenius Journal of Analytical Chemistry, Oct 13, 1998

The suitability of the single vessel principle (performing all steps of an analytical procedure i... more The suitability of the single vessel principle (performing all steps of an analytical procedure in one vessel) for cold vapour atomic absorption spectrometric determination of mercury in biological solids was evaluated. The single vessel method gave a lower mean blank level with better precision, hence lower detection limits, as compared to the conventional method. The determination of total mercury in biological standard reference materials by the single vessel method also produced significantly higher mercury values and better precision than the conventional method. However, the mercury concentrations obtained in certified reference materials by the use of both methods were close to the mean certified values. Moreover, the use of the single vessel method is cost effective, rapid and environment friendly. The use of the single vessel technique is therefore recommended for accurate and reliable determination of mercury in biological solids.

Analytical Sciences, Aug 1, 1997

The charring of samples and loss of mercury by a nitric-sulfuric acid mixture has been overcome b... more The charring of samples and loss of mercury by a nitric-sulfuric acid mixture has been overcome by prior digestion with nitric acid, followed by the addition of sulfuric acid into the final solution. This approach provides optimum decomposition and analytical conditions for a reliable cold vapor atomic absorption spectrometric determination of mercury in biological and environmental materials. In all cases, the presence of sulfuric acid improved the sensitivity of the mercury response significantly. Furthermore, the prior-and post-addition of sulfuric acid gave similar sensitivity and mercury concentrations for all samples. The adequacy of the prior digestion with nitric acid and post-addition sulfuric acid for reliable mercury determination was successfully demonstrated for blood, bone, bovine liver, mushroom, lake sediment, peat and prawn samples. Keywords Cold vapor atomic absorption spectrometry, mercury, wet digestion, biological and environmental materials Cold vapor atomic absorption spectrometry (CV-AAS) is the preferred technique for the determination of trace/ultra-trace concentrations of mercury in various samples because of its ease of operation and attainment of a much lower detection limit. l'2 However, like other techniques, the decomposition of the solid samples and, when necessary, the conversion of mercury to the divalent form, are required for an accurate determination by CV-AAS. Some of the approaches that have been employed for this purpose include the use of nitric acid3-5 and its mixture with sulfuric acid"6'7, hydrochloric acid8 and perchloric acid.6,9,1o The oxidizing power of the digestion acid or mixtures is often supplemented with the addition of either H2O2, KMn04, V205, K2Cr207 or K2S204,5,11-14 A recent evaluation of some of these digestion methods in our laboratories revealed that the nitric-sulfuric acid mixtures was most effective for the CV-AAS determination of mercury in biological and environmental materials.15 However, it was noted that complete recovery of organomercury was not accomplished in some cases. Nevertheless, the recovery of organomercury obtained with the use of nitric-sulfuric acid mixture t To whom correspondence should be addressed.

Materials Chemistry and Physics, Jun 1, 1993

The speciation of antimony and manganese (activators for fluorescent lamp phosphors) in samples o... more The speciation of antimony and manganese (activators for fluorescent lamp phosphors) in samples of commercial calcium halophosphate phosphors for fluorescent lamps was investigated. The total antimony content was determined by flame atomic absorption spectrometry (FAAS), and the antimony(II1) content by controlled-current coulometric titration. A method for examination of manganese speciation was proposed. Manganese forms were investigated by the partial dissolution technique using various agents and by FAAS analysis. The proposed methods can successfully be applied for control of phosphor properties and manufacturing processes.