Comparison of Wet Ashing and Dry Ashing for the Determination of Arsenic in Marine Organisms, Using Methylated Arsenicals for Standards

1974 ◽  
Vol 57 (6) ◽  
pp. 1363-1365 ◽  
Author(s):  
John F Uthe ◽  
Harry C Freeman ◽  
John R Johnston ◽  
Paula Michalik
Keyword(s):  
Total Arsenic ◽  
Acid Digestion ◽  
Fish Tissues ◽  
Digestion Procedure ◽  
Dry Ashing ◽  
Nitric Acid Digestion ◽  
Wet Ashing ◽  
The Difference ◽  
Fish And Shellfish

Abstract A vanadium catalyzed pentoxide-sulfuric acid-nitric acid digestion procedure is described which gave higher values for total arsenic than the AOAC dry ash procedure with fish and shellfish tissue. Recoveries of added methylarsenic compounds were also lower by dry ashing procedures but essentially complete by the new ashing procedure. Arsenic levels in a variety of shellfish and fish tissues as determined by wet ashing averaged 6.3% higher than dry ash values. In lobster hepatopancreas the difference was 13.1% for a large number of samples from a number of sampling areas.

Adaptation of a Dry Ashing Procedure for Determination of Selenium by Fluorimetry in High-Fat Foods

1995 ◽  
Vol 78 (2) ◽  
pp. 477-479 ◽  
Author(s):  
Jacques R Bellanger
Keyword(s):  
Magnesium Nitrate ◽  
High Fat ◽  
Fluorimetric Determination ◽  
Digestion Method ◽  
Wet Digestion ◽  
Dry Ashing ◽  
Selenium Determination ◽  
Wet Ashing ◽  
Total Procedure

Abstract The wet ashing–dry ashing procedure for destruction of organic matter in high-fat foods for subsequent fluorimetric determination of selenium was investigated. Samples were decomposed by predigestion with nitric acid and dry-ashed with magnesium nitrate and hydrochloric acid. Selenium was recovered quantitatively through the total procedure. Detection limit was about 4 ppb. Accuracy was tested by analysis of several reference materials and by comparison with the wet-digestion method. The present method can be used conveniently for selenium determination in high-fat foods.

Collaborative Study of the Determination of Lead in Alkyd and Latex Paints

1974 ◽  
Vol 57 (3) ◽  
pp. 614-617
Author(s):  
Warren K Porter
Keyword(s):  
Statistical Analysis ◽  
Paint Film ◽  
Collaborative Study ◽  
Atomic Absorption Spectrophotometry ◽  
Acid Digestion ◽  
Absorption Spectrophotometry ◽  
Coefficients Of Variation ◽  
Nitric Acid Digestion ◽  
Minimal Bias

Abstract A collaborative study was conducted on the determination of lead in alkyd and latex paints by atomic absorption spectrophotometry after nitric acid digestion. Fourteen samples of blank paints and paints with known additions of lead were analyzed by 10 collaborators. Coefficients of variation from 4 to 16% were obtained for 0.33 to 0.02% lead in the paint solids. The statistical analysis indicates minimal bias and adequate precision for the analysis of lead in paints at the current regulatory limit (0.5% in the paint solids or dry paint film). The method has been adopted as official first action.

Dry Ashing Method for the Determination of Total Arsenic in Poultry Tissues

1969 ◽  
Vol 52 (5) ◽  
pp. 930-932
Author(s):  
Joseph L Morrison ◽  
Glenn M George
Keyword(s):  
Magnesium Oxide ◽  
Magnesium Nitrate ◽  
Arsenic Content ◽  
Total Arsenic ◽  
Tissue Samples ◽  
Dry Ashing ◽  
Poultry Tissues

Abstract A method is described for the determination of arsenic in poultry tissue, which is sensitive to levels of less than 0.1 ppm. Tissue samples are dry-ashed in the presence of magnesium oxide and magnesium nitrate and the arsenic is determined colorimetrically with silver diethyldithiocarbamate. Arsenic content in the tissue is determined from standard curves prepared for each tissue; this technique corrects for losses during the ashing step.

Determination of Trace Elements in Water by Inductively Coupled Plasma–Mass Spectrometry: Collaborative Study

1994 ◽  
Vol 77 (4) ◽  
pp. 1004-1023 ◽  
Author(s):  
J E Longbottom ◽  
T D Martin ◽  
K W Edgell ◽  
S E Long ◽  
M R Plantz ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Trace Elements ◽  
Inductively Coupled Plasma ◽  
Acid Digestion ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Relative Standard ◽  
Nitric Acid Digestion ◽  
Plasma Mass Spectrometry

Abstract A joint U.S. Environmental Protection Agency (U.S. EPA)—AOAC interlaboratory method validation study was conducted on U.S. EPA method 200.8, Determination of Trace Elements in Waters and Wastes by Inductively Coupled Plasma–Mass Spectrometry. The purpose of the study was to determine and compare the mean recovery and precision of the inductively coupled plasma–mass spectrometry (ICP–MS) analyses for 20 trace elements in reagent water, drinking water, and groundwater. The formal study was based on Youden’s nonreplicate plan for collaborative tests of analytical methods. The test waters were spiked with the 20 trace elements at 6 concentration levels in the 0.8–200 μg/L range, prepared as 3 Youden pairs. Thirteen collaborators spiked 100 mL aliquots of the test waters, acidified them with 1 mL concentrated HNO3 and 0.5 mL concentrated HCl, reduced the volume to 20 mL by heating in an open beaker at 85°C, refluxed them for 30 min at 95°C, and diluted them to 50 mL. After centrifuging or settling the samples, a 20 mL portion of the supernatant was diluted to 50 mL and analyzed by ICP–MS. Related experiments evaluated the method performance in wastewater and wastewater digestate at a single concentration pair, and an alternative nitric acid digestion procedure. Mean recoveries for reagent water, drinking water, and groundwater were generally 95–105% with between-laboratory relative standard deviations about 4–8%. The method also worked well with wastewaters and digestate, with between-laboratory relative standard deviations averaging 8% and recoveries averaging 100%. Recoveries of silver, however, were low in all matrixes at concentrations over 100 μg/L. The nitric acid digestion procedure was comparable in accuracy and precision to the mixed-acid digestion in U.S. EPA method 200.8. The method was adopted first action by AOAC INTERNATIONAL.

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