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.

Collaborative Study of a Method for the Atomic Absorption Spectrophotometric and Polarographic Determination of Cadmium in Food

1973 ◽  
Vol 56 (4) ◽  
pp. 876-881
Author(s):  
Raymond J Gajan ◽  
John H Gould ◽  
James O Watts ◽  
John A Fiorino
Keyword(s):  
Phase I ◽  
Atomic Absorption ◽  
Orange Juice ◽  
Collaborative Study ◽  
Atomic Absorption Spectrophotometry ◽  
Absorption Method ◽  
Acid Digestion ◽  
Absorption Spectrophotometry ◽  
Coefficients Of Variation

Abstract The method studied involves acid digestion, dithizone extraction, and determination by atomic absorption spectrophotometry and polarography. This study consisted of 2 phases, with 10 laboratories participating in Phase I and 15 laboratories in Phase II. The 12 commodities studied (lettuce, potatoes, orange juice, shredded wheat, milk, sugar, eggs, fish, frankfurters, rice, beans, and oysters) were spiked at 0.05, 0.1, 0.2, 0.4, 0.5, 1.0, 1.5, and 2.0 ppm cadmium. Only 3 collaborators submitted polarographic results. There were no statistically demonstrable differences for the atomic absorption method between spiking levels, commodities, or laboratories. Coefficients of variation were acceptable. The atomic absorption spectrophotometric method for determining cadmium has been adopted as official first action.

Determination of Lead in Fish by Atomic Absorption Spectrophotometry and by Polarography. II. Collaborative Study

1972 ◽  
Vol 55 (4) ◽  
pp. 733-736
Author(s):  
Raymond J Gajan ◽  
Damon Larry
Keyword(s):  
Atomic Absorption ◽  
Collaborative Study ◽  
Atomic Absorption Spectrophotometry ◽  
Polarographic Method ◽  
Absorption Spectrophotometry ◽  
Paired Samples ◽  
Coefficients Of Variation ◽  
Different Types ◽  
Average Lead

Abstract Nineteen laboratories, using 6 different models of atomic absorption spectrophotometers and 4 different types of polarographs, participated in this collaborative study. The average lead recoveries from 6 paired samples at 1–2, 5–6, and 10–11 ppm levels were 97.7% by polarography and 100.7% by atomic absorption. The average standard deviations were 0.32 and 0.41 ppm, respectively, and the average coefficients of variation were 7.9 and 13.1%, respectively. With collaborators reporting on both methods, the results of the overall method average were 4.3 ppm for polarography and 4.4 ppm for atomic absorption. Since there were no significant differences (p > 0.05) found between the method averages, except at one of the unspiked levels, the 2 methods can be used to confirm each other at levels of 1-11 ppm. The polarographic method has been adopted as official first action for the determination of lead in fish.

Collaborative Study of a Method for Determining Lead in Plant and Animal Products

1972 ◽  
Vol 55 (4) ◽  
pp. 737-740
Author(s):  
William L Hoover
Keyword(s):  
Nitric Acid ◽  
Collaborative Study ◽  
Atomic Absorption Spectrophotometry ◽  
Carbonate Dissolution ◽  
Animal Products ◽  
Absorption Spectrophotometry ◽  
Coefficients Of Variation ◽  
Strontium Sulfate ◽  
Co Precipitation

Abstract A method for the determination of lead in food products was collaboratively studied. The method involves co-precipitation of lead with strontium sulfate, conversion to carbonate, dissolution in nitric acid, and determination by atomic absorption spectrophotometry. Eight collaborating laboratories reported analytical results for 24 test samples. Results indicated that the systematic error was essentially the same as the random error at the 99% level. Acceptable coefficients of variation were observed. The method has been adopted as official first action.

Determination of Lead in Evaporated Milk by Atomic Absorption Spectrophotometry and Anodic Stripping Voltammetry: Collaborative Study

1973 ◽  
Vol 56 (5) ◽  
pp. 1246-1251
Author(s):  
John A Fiorino ◽  
Robert A Moffitt ◽  
Albert L Woodson ◽  
Raymond J Gajan ◽  
Glen E Huskey ◽  
...  
Keyword(s):  
Atomic Absorption ◽  
Anodic Stripping Voltammetry ◽  
Collaborative Study ◽  
Stripping Voltammetry ◽  
Atomic Absorption Spectrophotometry ◽  
Absorption Spectrophotometry ◽  
Coefficients Of Variation ◽  
Anodic Stripping ◽  
Ppm Level

Abstract A method for the determination of lead in evaporated milk was successfully collaborated by 11 laboratories. Five laboratories used both atomic absorption spectrophotometry (AAS) and anodic stripping voltammetry (ASV) for the determination, 5 used only the atomic absorption method, and 1 used only the polarographic method. Each collaborator received 12 samples, 2 at each of the 5 different levels (0.06–0.95 ppm) and 2 practice samples with a known lead content. Both AAS and ASV were equally suitable for the determination of lead in the concentration range studied. The pooled variation between duplicate determinations was 0.0010 and 0.0016 for the AAS and ASV methods, respectively. For the AAS determinations the coefficients of variation (random error components) decreased from 43% at the lowest Pb level to 4% at the highest level. Although the ASV results did not show the same regularity of decreasing coefficients of variation with increasing Pb level, the coefficients of variation were acceptable: 28% at the 0.06 ppm level and 6% at the 0.22 ppm level. The AAS method has been adopted as official first action and the ASV method as interim official first action.

Atomic Absorption Spectrophotometric Determination of Lead, Cadmium, Zinc, and Copper in Clams and Oysters: Collaborative Study

1977 ◽  
Vol 60 (6) ◽  
pp. 1400-1407
Author(s):  
Stephen G Capar
Keyword(s):  
Atomic Absorption ◽  
Butyl Acetate ◽  
Collaborative Study ◽  
Atomic Absorption Spectrophotometry ◽  
Flame Atomic Absorption Spectrophotometry ◽  
Absorption Spectrophotometry ◽  
Flame Atomic Absorption ◽  
Coefficients Of Variation ◽  
Aspiration Technique

Abstract In the method studied, clams and oysters are dry ashed at 475°C, the ash is dissolved in dilute HNO3, and Pb, Cd, Zn, and Cu are determined by flame atomic absorption spectrophotometry (AAS). Sample solutions containing levels of Pb and Cd too low for direct AAS are extracted as the 1-pyrrolidinecarbodithioate complex into n-butyl acetate before AAS. The method was subjected to a collaborative study to determine the precision and accuracy of the analysis. Concentration ranges in the samples studied were approximately 0.06–2 ppm Pb, 0.03–2 ppm Cd, 40–600 ppm Zn, and 5–50 ppm Cu. Within these ranges, Cd levels <0.5 ppm and Pb at all levels required extraction prior to AAS. The average coefficients of variation for Pb, Cd, Zn, and Cu were, respectively, 66.0, 93.2, 8.5, and 20.5% for the lowest levels and 13.5, 3.8, 6.7, and 6.8% for the highest levels. Recoveries were computed by using the sum of the average collaborative results for the totally unfortified samples plus the fortification levels as the expected concentration. The average recoveries of Pb, Cd, Zn, and Cu were, respectively, 94.0, 99.7, 99.3, and 100.2 % for the lowest fortification level and 94.8, 95.6, 96.5, and 97.5% for the highest level. High levels of Cu and/or Zn caused incomplete extraction of Pb and Cd, with Cd being affected more severely than Pb. Data obtained also suggest that background corrections may be needed for determining Zn and Cd with the direct aspiration technique. No recommendation is made for official action.

Determination of Minor Nutrients in Fertilizers by Atomic Absorption Spectrophotometry: Second Collaborative Study

1965 ◽  
Vol 48 (6) ◽  
pp. 1100-1103
Author(s):  
C H Mcbride
Keyword(s):  
Atomic Absorption ◽  
Collaborative Study ◽  
Atomic Absorption Spectrophotometry ◽  
Absorption Method ◽  
Atomic Absorption Method ◽  
Absorption Spectrophotometry ◽  
Minor Nutrients

Abstract The atomic absorption method studied last year was re-examined and extended to include calcium and sodium. The procedures were submitted to 16 collaborators for determination of Ca, Cu, Fe, Mg, Mn, Na, and Zn. Results for Ca and Na were discouraging; further study is recommended.

Interlaboratory Study of Blood Selenium Determinations

1987 ◽  
Vol 70 (4) ◽  
pp. 664-667
Author(s):  
Tee-Siaw Koh
Keyword(s):  
Hydride Generation ◽  
Atomic Absorption Spectrophotometry ◽  
Bovine Blood ◽  
Blood Samples ◽  
X Ray ◽  
Absorption Spectrophotometry ◽  
Coefficients Of Variation ◽  
The Mean ◽  
Se Deficiency

Abstract Fifty-one laboratories from 14 countries participated in a survey on the determination of selenium (Se) in 8 bovine blood samples with Se concentrations ranging from 0.2 μmol/L (0.016 μg/mL) to 14 μmol/L (1.1 μg/mL). The methods used (and the percentage of participants using each method) were fiuorometry (61), hydride-generation atomic absorption spectrophotometry (AAS) (23), graphitefurnace AAS (6), gas chromatography (4), neutron activation analysis (4), and X-ray fiuorometry (2). There was little difference in the mean Se results obtained by fiuorometry or hydride-generation AAS (P > 0.05). Mean intralaboratory coefficients of variation (CVs) from known replicates ranged from 4 to 14% for all samples. Interlaboratory CVs were related to blood Se concentration and increased to 55% at Se levels below 0.4 μmol/L (0.032 μg/mL). Laboratories that used quality control (QC) schemes had lower interlaboratory CVs than those that did not, but the advantage began to diminish at blood Se concentration below 0.4 μmol/L (0.032 μg/mL). The high interlaboratory CVs, coupled with the false assurance from the low intralaboratory CVs and the ineffectiveness of the QC schemes at blood Se concentrations below 0.4 μmol/L (0.032 μg/mL), are of concern in diagnosis of marginal Se deficiency in livestock where the concentrations of interest are in the range 0.15-0.5 μmol/L (0.012-0.039 μg/mL).

Collaborative Study Using Atomic Absorption Spectrophotometry for the Determination of Copper in Alcoholic Products

1967 ◽  
Vol 50 (2) ◽  
pp. 338-339
Author(s):  
Duane H Strunk ◽  
A A Andreasen
Keyword(s):  
Atomic Absorption ◽  
Spectrophotometric Method ◽  
Collaborative Study ◽  
Atomic Absorption Spectrophotometry ◽  
Good Precision ◽  
Absorption Method ◽  
Standard Curve ◽  
Absorption Spectrophotometry ◽  
Determination Of Copper

Abstract A collaborative study was conducted on the 'atomic absorption spectrophotometric method for measuring the concentration of copper in alcoholic products. In this method, the samples are aspirated directly into the burner of the instrument, and the absorhance values are converted to ppm copper by reference to a standard curve. Data show good precision and are comparable to those obtained by the ZDBT method. It is recommended that the atomic absorption method be adopted as official, first action.

Atomic Absorption Spectrophotometric Method for Determination of Water-Soluble Copper in Water-Insoluble Copper Fungicides: CIPAC Collaborative Study. Comparison with Bathocuproine Method

1981 ◽  
Vol 64 (1) ◽  
pp. 75-78
Author(s):  
F Sánchez Rasero ◽  
◽  
P G Balayannis ◽  
H P Beyers ◽  
E Celma ◽  
...  
Keyword(s):  
Atomic Absorption ◽  
Collaborative Study ◽  
The United States ◽  
Atomic Absorption Spectrophotometry ◽  
Water Soluble ◽  
Absorption Spectrophotometry ◽  
Aas Method ◽  
Standard Deviations ◽  
The Difference

Abstract An atomic absorption spectrophotometric (AAS) method was collaboratively studied by 8 laboratories from Africa, the United States, Australia, and Europe. The samples were dispersed in deionized water. After centrifuging and filtering, the water-soluble copper in the filtrate was acidified and measured by atomic absorption spectrophotometry, in an airacetylene flame, at 324.7 nm. The results from 7 laboratories were satisfactory and no unfavorable comments were received. Repeatability standard deviations ranged from 0.005 to 0.023, and reproducibility standard deviations ranged from 0.012 to 0.062. When compared with the bathocuproine method, the difference in bias between both methods is not significant. They were both adopted as full CIPAC methods, with the bathocuproine method as the referee method. Both methods have been adopted official first action.

Atomic Absorption Spectrophotometric Method for Determination of Polydimethylsiloxane Residues in Pineapple Juice: Collaborative Study

1990 ◽  
Vol 73 (5) ◽  
pp. 721-723
Author(s):  
Robert D Parker
Keyword(s):  
Nitrous Oxide ◽  
Atomic Absorption ◽  
Spectrophotometric Method ◽  
Collaborative Study ◽  
Atomic Absorption Spectrophotometry ◽  
Pineapple Juice ◽  
Absorption Spectrophotometry ◽  
Relative Standard ◽  
Standard Deviations

Abstract An atomic absorption spectrophotometric method for determination of polydimethylsiloxane (PDMS) residues In pineapple juice was collaboratively studied by 9 laboratories. PDMS residues are extracted from pineapple Juice with 4- methyl-2-pentanone and the extracted silicone Is measured by atomic absorption spectrophotometry using a nitrous oxide/ acetylene flame. Collaborators analyzed 5 samples Including 1 blind duplicate. Reproducibility relative standard deviations (RSDR) were 13.1% at 31 ppm, 6.9% at 18 ppm, 14.8% at 7.9 ppm, and 16.1 % at 4.9 ppm PDMS. The method has been approved Interim official first action by AOAC.

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