FAAS Determination of Calcium in Shrimp Shell Liquor Fermented by Lactobacilli

FAAS was applied to the determination of calcium in lactobacilli-fermentation liquor of shrimp shell. Linear relationship between values of absorbance and mass concentration of Ca2+ was obtained in the range within 24.0 mg·L-1. Detection limit (3s) found was 0.065 mg·L-1. Recovery was tested by addition of standard calcium solution (10.00 mg·L-1) to fermentation liquor samples (containing 10.67 mg·L-1 of Ca2+), value of average recovery found was 101.2%. Precision was tested by replicate determination of Ca2+ in a substantial sample (wCa 1.33%) by the present method, value of RSD (n=6) found was 0.37%. Average results of (w) 1.39% in consistency with the known value, was obtained by the EDTA titrimetric method with value of RSD (n=6) 0.59%. It was proved that the presence of organic substances in the sample solution did not show any interference to the determination of Ca2+ by the present method.