AOAC Methods for Review in Codex STAN 234_11-2018

AOAC Official Methods Listed in CXS 234 for Milk and Milk Products

71

Read concentration of analytes from plot of absorbance against m g/mL. E. Calculations

or equivalent. If filtrate is cloudy, refilter immediately through fine paper (Whatman No. 5, or equivalent). Redilute, if necessary, with 0.5M HCl. D. Determination (P interferes in Ca and may interfere in Mg determination with air–C 2 H 2 burners. Eliminate interference by adding La stock solution to standard and test solutions so that final dilutions contain 1% La. P does not interfere with Ca determination when N 2 O–C 2 H 2 flame is used.) Set up instrument as in Table 965.09 , or previously established optimum settings for apparatus to be used. Less sensitive secondary lines [Gatehouse & Willis, Spectrochim. Acta 17 , 710(1961)] may be used to reduce necessary dilution, if desired. Read ³ 4 standard solutions within analysis range before and after each group of 6–12 test solutions. Flush burner with H 2 O between test solutions, and re-establish 0 absorption point each time. Prepare calibration curve from average of each standard before and after each group.

Percent element = ( m g/mL) ´ (F/test portion weight ) ´ 10 –4

F = mL original dilution ´ mL final dilution/mL aliquot, if original 100 mL volume is diluted. References: JAOAC 48, 406, 1100(1965); 50, 401(1967); 51, 847(1968); 58, 928(1975).

CAS-7440-70-2 (calcium) CAS-7440-50-8 (copper) CAS-7439-89-6 (iron) CAS-7439-95-4 (magnesium) CAS-7439-96-5 (manganese) CAS-7440-66-6 (zinc)

ã 2005 AOAC INTERNATIONAL

10/9/2018