scholarly journals Fast and accurate methodology for direct mercury determination in hair and nails

2016 ◽  
Vol 2 (1) ◽  
Author(s):  
A. Vicent ◽  
M.L. Cervera ◽  
A. Morales-Rubio
Keyword(s):  
Total Mercury ◽  
Certified Reference Materials ◽  
Coal Fly Ash ◽  
Previous Treatment ◽  
Rice Flour ◽  
Hair Mercury ◽  
History Of ◽  
Certified Values ◽  
Good Agreement

AbstractA solvent-free, easy, fast and waste-free methodology was developed for the determination of total mercury levels in hair and nails. Samples were taken from several volunteers and directly analysed, with levels of mercury in the range between 0.5 and 8 ng/mg. The influence of quantity of hair, as well as the addition of small amount of solvent and the necessity of previous treatment were studied. Also, a history of mercury exposure was provided by the distance of the hair from the scalp of each volunteer, the results of which were correlated with fish consumption. Furthermore, a short study of mercury in nails was carried out and correlated to the results from hair mercury levels. A small quantity of 5 mg of hair with an addition of 50 μL of water to the sample without previous treatment was adequate to get a representative result in less than 10 minutes. The accuracy of the proposed method was confirmed by analysing certified reference materials including Coal Fly Ash-NIST SRM 1633b, Fucus-IAEA 140 and three unpolished Rice Flour NIES-10. The observed results were found to be in good agreement with the certified values.

scholarly journals SEQUENTIAL MULTI-ELEMENT DETERMINATION OF TRACE-METALS IN BIODIESEL SAMPLES USING HR-CS FAAS

Química Nova ◽  
2020 ◽  
Author(s):  
Alexandre Jesus ◽  
Ariane Zmozinskia ◽  
Diane Laroque ◽  
Márcia Silva
Keyword(s):  
Absorption Spectrometry ◽  
Element Determination ◽  
Continuum Source ◽  
Flame Atomic Absorption ◽  
Student’S T ◽  
Different Sources ◽  
Certified Values ◽  
Good Agreement ◽  
Student’S T Test

In this work the feasibility of sequential multi-element determination of Zn, Fe, Mg, Cu, Na, K, Cr, Al and Ca in biodiesel samples by high-resolution continuum source flame atomic absorption spectrometry (HR-CS FAAS) was investigated. Biodiesel samples obtained from different sources and different chemical processes were analysed. The samples were diluted with n-propanol and water (1.4 mol L-1 HNO3) to form a microemulsion (ME) before its introduction in the HR-CS FAAS using a flow injection mode. The sample B-01 (obtained from soybean oil) was used for optimisation of the instrumental parameters. The accuracy of the proposed method was checked by analysis of certified reference material (CRM) Conostan BDM2A (for K and Na) and BDM2B (for Ca and Mg) and by comparison with acid digestion and recovery tests (for Zn, Fe, Cu, Cr and Al). The obtained results for CRM analysis showed good agreement with certified values within 95% of confidence (Student’s t-test). Recovery tests values ranged from 87-114%. The method developed for the analysis of biodiesel samples is accurate, simple, fast, and suitable for routine application.

Online Preconcentration System Using 6-(2-Thienyl)-2-Pyridine Carboxaldehyde Functionalized Amberlite XAD-4 Resin for the Determination of Trace Elements in Waters by Flame Atomic Absorption Spectrometry

2013 ◽  
Vol 96 (3) ◽  
pp. 642-649 ◽  
Author(s):  
Cennet Karadaş ◽  
Derya Kara
Keyword(s):  
Trace Elements ◽  
Atomic Absorption Spectrometry ◽  
Atomic Absorption ◽  
Flame Atomic Absorption Spectrometry ◽  
Water Samples ◽  
Certified Reference Materials ◽  
Absorption Spectrometry ◽  
Rice Flour ◽  
Flame Atomic Absorption

Abstract An online flow injection method was developed for the determination of trace elements in waters using 6-(2-thienyl)-2-pyridinecarboxaldehyde functionalized Amberlite XAD-4 resin. The metals were eluted with 1.0 M HNO3 directly to a flame atomic absorption spectrometry determination system. The sorption capacities of the resin for metal ions were 74.6, 113.7, 48.3, 131.6, and 88.6 μmol/g for Cd(II), Ni(II), Pb(II), Co(II), and Cu(II), respectively. The resin was found to be very stable and capable of being used for more than 250 retention and elution cycles without major loss of performance. Detection limits (3SD) were determined to be 0.14 μg/L for Cd, 0.39 μg/L for Cu, 0.82 μg/L for Ni, 0.88 μg/L for Co, and 2.54 μg/L for Pb using 10 mL sample loading. The accuracy of the proposed method was checked using different certified reference materials [estuarine water (SLEW-3), riverine water (SRLS-5), 19-element aqueous standard (QCS-19), wheat flour (NBS 1567 a), and rice flour unpolished high level Cd (NIES 10c)]. Results were in agreement with certified values. The proposed method was applied to the determination of Cu, Ni, Co, Cd, and Pb in natural water samples. The recovery values for spiked water samples were between 91.9 and 107.4%.

Innovations in Atomic Absorption Spectrophotometry with Electrothermal Atomization for Determining Lead in Foods

1982 ◽  
Vol 65 (4) ◽  
pp. 994-998
Author(s):  
Theodore C Rains ◽  
Theresa A Rush ◽  
Therese A Butler
Keyword(s):  
Atomic Absorption ◽  
Ammonium Phosphate ◽  
Atomic Absorption Spectrophotometry ◽  
Oyster Tissue ◽  
Absorption Spectrophotometry ◽  
Matrix Modification ◽  
Precision And Accuracy ◽  
Certified Values ◽  
Good Agreement

Abstract A simple and rapid method is described for the determination of lead in foods. The samples are digested in HNO3, HF, and HCIO4 and then the lead is determined by atomic absorption spectrophometry using an electrothermal atomizer with the L'vov platform. Interferences and ways to improve the precision and accuracy of the analysis were studied. Matrix modification using 1% ammonium phosphate alleviated most interferences encountered. The precision and accuracy of the method was evaluated using NBS SRM 1570 Spinach and SRM 1566 Oyster Tissue. The values obtained are in good agreement with the certified values.

Enrichment analysis of uranium in uranium oxide by gamma-ray spectrometry without using calibration standards

2000 ◽  
Vol 88 (2) ◽  
Author(s):  
Y. Nir-El
Keyword(s):  
Gamma Rays ◽  
Uranium Oxide ◽  
Gamma Ray ◽  
Enrichment Analysis ◽  
Gamma Ray Spectrometry ◽  
Uranium Enrichment ◽  
Calibration Standards ◽  
Certified Values ◽  
Good Agreement

An analytical method for the determination of uranium enrichment in uranium oxide without using any calibration standards is described. Very good agreement between the measured and certified values was obtained in the analysis of a Standard Reference Material. Precise energies and emission probabilities were derived for two weak gamma-rays of

scholarly journals A Novel Method for Speciation of Chromium: Coprecipitation Without Carrier Element by Using a Triazole Derivative

2009 ◽  
Vol 92 (1) ◽  
pp. 257-262 ◽  
Author(s):  
Celal Duran ◽  
Volkan N Bulut ◽  
Duygu Ozdes ◽  
Ali Gundogdu ◽  
Mustafa Soylak
Keyword(s):  
Certified Reference Materials ◽  
Sample Volume ◽  
Chromium Vi ◽  
Technology Standard ◽  
Preconcentration Factor ◽  
Novel Method ◽  
The Difference ◽  
Certified Values ◽  
Carrier Element

Abstract A coprecipitation method has been established for speciation of chromium(III) and chromium(VI) in real samples. The procedure is based on the coprecipitation of Cr(III), by using a new organic coprecipitant, 3-phenyl-4-o-hydroxybenzylidenamino-4,5-dihydro-1,2,4-triazole-5-one, without adding any carrier element. After reduction of Cr(VI) by concentrated H2SO4 and ethanol, the method was applied to the determination of total Cr. The level of Cr(VI) was calculated by the difference of total Cr and Cr(III) levels. For optimum recovery of Cr(III), different analytical factors such as pH, amount of coprecipitant, centrifugation rate and time, and effect of sample volume, were investigated. The influences of some anions, cations, and transition metals on the recoveries were also investigated, and no significant interferences were observed. The preconcentration factor was 100. The detection limit based on 3 times standard deviation () of the blank (n = 10) for Cr(III) was 0.50 g/L. In order to evaluate the accuracy of the method, certified reference materials (CRM-TMDW-500 Drinking Water and National Institute of Standards and Technology Standard Reference Material 1573a Tomato Leaves) were analyzed, and the results obtained were in good agreement with certified values. The presented procedure was applied for Cr speciation in various solid and liquid samples with successful results.

State-by-State Use of AMA Guides

2019 ◽  
Vol 24 (5) ◽  
pp. 3-7, 16
Keyword(s):  
Expert Testimony ◽  
Narrow Range ◽  
The United States ◽  
Workers Compensation ◽  
Federal Employees ◽  
Permanent Disability ◽  
Sixth Edition ◽  
History Of ◽  
Canadian Provinces

Abstract This article presents a history of the origins and development of the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), from the publication of an article titled “A Guide to the Evaluation of Permanent Impairment of the Extremities and Back” (1958) until a compendium of thirteen guides was published in book form in 1971. The most recent, sixth edition, appeared in 2008. Over time, the AMA Guides has been widely used by US states for workers’ compensation and also by the Federal Employees Compensation Act, the Longshore and Harbor Workers’ Compensation Act, as well as by Canadian provinces and other jurisdictions around the world. In the United States, almost twenty states have developed some form of their own impairment rating system, but some have a narrow range and scope and advise evaluators to consult the AMA Guides for a final determination of permanent disability. An evaluator's impairment evaluation report should clearly document the rater's review of prior medical and treatment records, clinical evaluation, analysis of the findings, and a discussion of how the final impairment rating was calculated. The resulting report is the rating physician's expert testimony to help adjudicate the claim. A table shows the edition of the AMA Guides used in each state and the enabling statute/code, with comments.

COMPARATIVE ACTION OF VARIOUS OESTROGENIC COMPOUNDS ON MOUSE VAGINAL SIALIC ACIDS (II)

1969 ◽  
Vol 62 (4) ◽  
pp. 663-670 ◽  
Author(s):  
Lars Carlborg
Keyword(s):  
Sialic Acid ◽  
Response Curve ◽  
Sialic Acids ◽  
Clear Cut ◽  
Suitable Parameter ◽  
Sufficient Degree ◽  
Comparative Action ◽  
Relative Potencies ◽  
Good Agreement

ABSTRACT Oestrogens administered in lower doses than necessary to induce full cornification of the mouse vagina induce mucification. It was shown previously that the degree of mucification could be estimated by quantitative determination of sialic acids. A suitable parameter for oestrogen assay was the measurement of vaginal sialic acid concentration which exhibited a clear cut dose response curve. Eleven assays of various oestrogens were performed with this method. Their estimated relative potencies were in good agreement with other routine oestrogen assays. A statistically sufficient degree of precision was found. The sensitivity was of the same order, or slightly higher, than the Allen-Doisy test.

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