AOAC Methods in Codex STAN 234 (Preliminary Methods Review)

CAJAN ET AL.: J. ASSOC. OH. ANAL. CHEM. (VOL. 65, NO, 4, 1982)

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Table 4. lnterlaboratory trial results for recoveriu • of cadmium and lead by DPASV /HMOE

Cadmium

Lead

Added, ppm

Food commodityb

found, ppm

Added. ppm

Found. ppm

Lab.

Rec.• %

Rec.,%

A

0 0

Green beans

<0.01 <0.01 0 .02 0.04 0.08 0.08 0.04 0.04 0.11 0.10 0.06 0.05 0.15 0.16 <0.01 <0.01 <0.01 <0.01 0.05 0.05 0 15 0.13 0.05 0.05 0.14 0.14 <0.01 <0.01 <0.01 <0.01 <001 <0.01

0 0

0.05 0.05 0.15 0.15

0.) 0.1 0.3 0.3 0 0 0.1 0.1 0.3 0.3 0.) 0.1 0.3 0.3 0 0 0.1 0.1 0.3 0.3 0 0 0.1 0.1 0.3 0.3 0.1 0.1 0.3 0.3 0 0 0 0

40 80 53 53 80 80 73 67

80 90 97 90

0.08 0.09 029 0.27

A

0 0

Infant formula

<0.01 <0.01

0.05 0.05 0.15 0.15 0 0 0.05 0.05 0.15 0.15 0.05 0.05 015 0.15 0 0 0.05 0.05 0.15 0.15 0.05 0.05 0.15 0.15 0 0 0 0

0.10 0.11 0.32 0.31 0.01 0 .05 0.11 0 .09 0.28 0.29 0.15 0.31 0.33 0.28 0.55 0.49

100 110 107 103

Baby beef

B

100° so, 90' 93'

120 100 100 107

Mackerel

B

100 100 100 87

100 50 107 87

C

Infant formula

<0.01 <0.01 0.09 0.09 0.29 0.29 <0.01 <0.01

90 90 97 97

100 100

93 93

C

Apple sauce

0.05,0.04 0.04,0.05

90 90 87 90

0.09. 0.09 0.09, 0.09

90 90 93 93

0.14 0.14

0.26 0.27

• Each recovery based on the average value of the duplicate unspiked results: ii result is below quant,taMn limit a value of O ppm was used. 11 lo g of each food. < Based on 0.01 ppm as unspiked sample.

sumcd that the high unspiked result was due t(J the contamination. Therefore, only the lower

An interlaboratory trial of the method was conducted by 3 FDA District laboratories. Each laboratory was instructed to purchase and pre– pare 2 assigned food commodities for analysis. They were asked to analyze duplicate 10 g sam– ples "as is" and duplicate 10 g samples after spiking with a known volume of spiking solu– tion prepared by our laboratory. Their results arc shown in Table 4. The cadmium recoveries of Laboratory A are consistently lower than those of the other 2 laboratories. The results obtained by Laboratory B for lead in the unspikcd baby beef and in the mackerel indicated either con– t<1mination or lack of homogeneity of these samples. Because results appeared to be high for only one unspiked baby beef sample, but for none of the spiked baby beef samples, we as-

Table 5.

lnterlaboratory trial results for dry baby cereal

Lead found. ppm

Lab.•

Cadmium found, ppm

0.20. 0.24, 0 36b 0.24. 0.25, 0.21 0.27. 0.26, 0.39° 0.24, 0.22, 0 .215

0.09, 0.10, 0.09 0.10.0.10,0.10 0.125, 0.11, 0.11 0.11.0.11, 011

A a C 0 E Mean" Range' CV,%"

0.20 0.23 0.07

0.105 0.035 9.44

10.3

4 Labs A-D used OPASV/HMDE: Lab. E used LSASV/ CMGE. b Outlier per Dixon's outlier test. < Minus outliers.

Codex Trial Method Review