Atomic Absorption Spectrophotometric Determination of Chelated Iron in Iron Chelate Concentrates: Collaborative Study

1983 ◽  
Vol 66 (4) ◽  
pp. 952-955
Author(s):  
James R Silkey ◽  
◽  
S G Angell ◽  
K Bartunek ◽  
L W Clark ◽  
...  
Keyword(s):  
Atomic Absorption ◽  
Collaborative Study ◽  
Ferric Hydroxide ◽  
Disodium Edta ◽  
Iron Chelate ◽  
Iron Citrate ◽  
Coefficients Of Variation ◽  
Chelated Iron ◽  
Aas Method

Abstract An atomic absorption Spectrophotometric (AAS) method for determining chelated iron in iron chelate concentrates was collaboratively studied by 13 laboratories. Nonchelated iron was selectively precipitated as ferric hydroxide from an aqueous solution of the sample by adjusting to pH 8.5 with sodium hydroxide. A filtered portion of the sample solution was diluted with 0.5N HC1, and the iron was determined by AAS using standards containing disodium EDTA. Six pairs of iron chelate materials (12 samples) were analyzed and the average coefficients of variation were iron EDTA 3.52%, iron HEDTA 4.16%, iron DTPA 3.55%, iron EDDHA 3.52%, iron citrate 2.86%, and iron DPS 8.47%. The method has been adopted 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.

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.

Atomic Absorption Spectrophotometric Determination of Mercury in Mercury≃Containing Drugs: Collaborative Study

1983 ◽  
Vol 66 (5) ◽  
pp. 1203-1206
Author(s):  
Walter Holak ◽  
◽  
R Baltz ◽  
L Elliott ◽  
E McGary ◽  
...  
Keyword(s):  
Atomic Absorption ◽  
Spectrophotometric Determination ◽  
Collaborative Study ◽  
Ophthalmic Solution ◽  
Mean Value ◽  
Antiseptic Solution ◽  
Aas Method ◽  
Low Levels

Abstract An atomic absorption spectrophotometric (AAS) method applicable to a wide variety of mercurycontaining drugs has been developed and subjected to a collaborative study. Samples were digested with a water-HCl-HN03 (4 + 3 + 1) mixture, and the mercury was determined in solution by AAS. High levels of mercury were measured with a conventional air-acetylene flame, whereas low levels were measured by the flameless technique. Each of 7 collaborators received duplicate synthetic samples of a tincture, an ophthalmic solution, and an antiseptic solution, and duplicate commercial samples of an ointment and an injectable. The overall mean value found by collaborators for mercury in these samples was 100.13%. The corresponding overall repeatability SD (CV, %) and reproducibility SD (CV, %) values were 2.18 (2.18) and 3.38 (3.38), respectively. The proposed AAS method has been adopted official first action.

Graphite Furnace Atomic Absorption Spectrophotometric Determination of 4-Hydroxy-3-Nitrobenzene Arsonic Acid in Finished Animal Feed: Collaborative Study

1986 ◽  
Vol 69 (5) ◽  
pp. 838-843
Author(s):  
Glenn M George ◽  
Larry J Fra ◽  
◽  
C F Aten ◽  
J Bestianich ◽  
...  
Keyword(s):  
Atomic Absorption ◽  
Animal Feed ◽  
Graphite Furnace ◽  
Collaborative Study ◽  
Method Performance ◽  
Relative Standard ◽  
Graphite Furnace Atomic Absorption ◽  
Aas Method ◽  
Arsonic Acid

Abstract Eight laboratories participated in a collaborative study of an atomic absorption spectrophotometric (AAS) method for determination of 4- hydroxy-3-nitrobenzene arsonic acid (roxarsone), which is administered in animal feed at levels of 25-50 ppm as a growth stimulant. The drug is extracted from feed by using aqueous 1% ammonium carbonate solution. Undissolved feed particles are allowed to settle, and then a diluted aliquot of the feed extract is analyzed for total arsenic by AAS using a graphite furnace for sample atomization. Collaborators performed single analyses on 18 samples which were randomly numbered blind duplicate pairs of a complete poultry ration fortified with roxarsone at concentrations from 22.5 to 55.0 ppm. Statistical evaluation of the collaborative data showed satisfactory method performance. Overall mean recovery of roxarsone was 100.4% and the overall relative standard deviation was 6.2%. The method has been adopted 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 Biuret in Urea and Mixed Fertilizers by Cupric Ion Selective Electrode

1986 ◽  
Vol 69 (1) ◽  
pp. 119-122
Author(s):  
Luis F Corominas ◽  
Roberto A Navarro ◽  
Pedro Rojas ◽  
José L Cruz
Keyword(s):  
Atomic Absorption ◽  
Copper Complex ◽  
Confidence Level ◽  
Collaborative Study ◽  
Ion Selective Electrode ◽  
Selective Electrode ◽  
Cupric Ion ◽  
Excess Copper ◽  
Aas Method

Abstract A method for determining biuret in urea and mixed fertilizers by using a cupric ion selective electrode (CISE) has been developed to take advantage of the simplicity of the apparatus. The method is based on the same principle as the atomic absorption spectrophotometric (AAS) method, 2.091-2.093: formation of a biuret-copper complex, elimination of excess copper, and determination of complexed copper. However, some changes were needed to eliminate starch and alcohol interferences. The method was tested for ruggedness and then compared with the AAS method for 4 fertilizer samples. Averages and variances were equivalent at the 99% confidence level according to t- and F-tests. A collaborative study is recommended to compare behavior of both methods in different laboratories.

Atomic Absorption Determination of Serum Copper: Collaborative Study

1983 ◽  
Vol 66 (5) ◽  
pp. 1140-1142 ◽  
Author(s):  
David L Osheim ◽  
◽  
H Casper ◽  
W Colvin ◽  
R J Emerick ◽  
...  
Keyword(s):  
Collaborative Study ◽  
Current Method ◽  
Serum Copper ◽  
External Control ◽  
Serum Samples ◽  
Coefficients Of Variation ◽  
Absorption Determination ◽  
Control Serum ◽  
Aas Method

Abstract Preliminary to conducting a collaborative study on a method for copper in serum, methods used by a selected group of laboratories were surveyed. The responding laboratories were supplied with a Youden pair of bovine serum samples and requested to use their current method for serum copper. Results of the analyses and the methods used were evaluated; hypotheses were developed in our laboratory to explain some of the interlaboratory variation. For the AAS method chosen, each of 12 collaborating laboratories analyzed one blind duplicate and 2 Youden pair of serum samples. A commercially available external control serum with a certified level of copper and a 1000 mg copper/L standard were also submitted. The method requires the serum to be diluted 1 + 1 with distilled water and the standards to be diluted with 10% glycerin to approximate the viscosity of the diluted serum. The intralaboratory coefficients of variation (CV) ranged from 2.24 to 4.40% and the interlaboratory CV ranged from 2.56% to 6.05%. The method has been adopted official first action.

Atomic Absorption Spectrophotometric Determination of Liver Copper: Collaborative Study

1985 ◽  
Vol 68 (1) ◽  
pp. 44-45 ◽  
Author(s):  
David L Osheim ◽  
Frank P Ross
Keyword(s):  
Atomic Absorption ◽  
Limit Of Detection ◽  
Collaborative Study ◽  
Bovine Liver ◽  
Atomic Absorption Spectrophotometry ◽  
National Bureau ◽  
Liver Sample ◽  
Liver Copper ◽  
Coefficients Of Variation

Abstract Eleven collaborating laboratories conducted replicate analyses on 4 blind duplicate pairs of bovine liver samples that either had naturally acquired copper levels or were spiked with one of 3 copper levels. A National Bureau of Standards Bovine Liver sample (SRM 1577, 193 ± 10 mg copper/kg) and a 1000 mg copper/L standard were also submitted to the collaborators. The method requires the tissue to be digested with concentrated HN03 at 60°C, diluted to volume with water, and analyzed by atomic absorption spectrophotometry. The intralaboratory coefficients of variation (CV„) ranged from 5.6 to 19%; the interlaboratory CVX values ranged from 7.1 to 21%. The lower limit of detection was estimated to be 1 mg copper/kg tissue. The method has been adopted official first action.

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