AOAC OMA# 2011.14 (Final Action Review)-OMB

2011.14 (MTE-01) MLT FOR ERP USE ONLY DO NOT DISTRIBUTE

P oitevin : J ournal of AOAC I nternational V ol . 95, N o . 1, 2012  181

Table 2011.14E. Interlaboratory study results for magnesium Matrix Mean, mg/kg Rec., % S r , mg/kg a RSD r , % b S R

, mg/kg c RSD R

, % d

HorRat No. of labs e Outlier labs f

Chocolate milk powder Dietetic milk powder 2

1746.74 439.31 859.48

98 38.46 2.20 51.03

2.92 3.04 4.12 4.30

0.56 0.48 0.71 0.82

8 9 7 8

2–SG

NS g

99

5.57 1.27 13.37

Infant cereal

98 33.62 3.91 35.38

2,6–DG

1714.02 (1680) h 102 56.83 3.32 73.68

Peanut butter NIST SRM 2387 Wheat gluten NIST RM 8418

2–SG

482.05 (510) h

95

8.52

1.77

16.53

3.43

0.54

9

NS

a  S r

= SD for repeatability (within laboratory).

b  RSD r

= RSD for repeatability.

c  S R

= SD for reproducibility (among laboratories).

matched standard calibrant solutions. An ionization buffer (cesium) and internal standards (chromium, indium, strontium, and yttrium) are used with or without appropriate in-line addition to minimize easily ionizable element (EIE) effects and to correct for physical and chemical interferences. = RSD for reproducibility. e  Reporting laboratories minus outliers. f  SG = Single Grubbs outlier; DG = Double Grubbs outlier. g  NS = Not significant. h  Certified or reference values. d  RSD R

manufacturer’s directions for safety risk, safety environment, and use of instruments. ( a )  ICP-OES spectrometer . ____ Instrument with axial, radial, or dual view grating configurations and autosampler, capable of determining multiple wavelengths for each element of interest with the required sensitivity. A three-channel peristaltic pump with or without appropriate in-line addition system (e.g., T connector) are linked between the peristaltic pump and nebulizer to avoid having to manually add ionization buffer and internal standards to each sample solution. A thermostatted cyclonic spray chamber is equipped with a micro-concentric nebulizer or other components designed to optimize aerosol and maximize

F. Instrumentation

Note : ICP-OES equipment must be used by qualified laboratory personnel who are familiar with the operation and maintenance of analytical systems; personnel must follow

Table 2011.14F. Interlaboratory study results for manganese Matrix Mean, mg/kg Rec., % S r , mg/kg a RSD r , % b S R

, mg/kg c RSD R

, % d HorRat No. of labs e Outlier labs f

NA g

NS h

Chocolate milk powder Dietetic milk powder 2

7.54 0.40

0.14 1.88

0.67

8.82 4.89 8.61 8.31

0.75 0.27 0.82 0.79

9 8 9 9

99

0.01 2.56 0.0197

2 – C

Infant cereal

16.74

NA 1.14 6.79

1.44 1.32

NS NS

15.85 (16.0) i

Peanut butter NIST SRM 2387 Wheat gluten NIST RM 8418

99

0.45 2.86

12.87 (14.3) i

90

0.23

1.75

1.13

8.75

0.80

9

NS

a  S r

= SD for repeatability (within laboratory).

b  RSD r

= RSD for repeatability.

c  S R

= SD for reproducibility (among laboratories).

d  RSD R = RSD for reproducibility. e  Reporting laboratories minus outliers.

f  C = Cochran outlier. g  NA = Not available. h  NS = Not significant. i  Certified or reference values.