Determination of Trace Lead in Fish Sauces by ID-ICP-MS After Mg(OH)2 Coprecipitation |
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Authors: | Xiang-Cheng Zeng Jian Li Hui-Bin Zheng |
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Institution: | College of Bioengineering , Jimei University , Xiamen , China |
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Abstract: | A method of isotope dilution coupled with inductively coupled plasma mass spectrometry (ID-ICP-MS) after Mg(OH)2 coprecipitation was employed to determine trace lead (Pb) in fish sauces. The pH values and the amounts of Mg2+ in the coprecipitation system and the amounts of isotopically enriched 206Pb reagent added in the measurement were optimized. Results showed that a recovery by adding standard was 92.0% with a relative standard deviation (RSD) of 0.39%. The detection limit estimated with the calculated method used in the study was 7.65 ng g?1. Through the Mg(OH)2 coprecipitation, more than 80% of matrix ions such as K+, Na+, and Ca2+ in the samples were effectively removed, and the trace Pb in fish sauces was largely enriched. The concentrations of Pb measured in 12 fish sauces ranged from 0.068 to 0.299 μg g?1, which was completely within the Pb limit (0.50 μg g?1), a hygienic standard for aquatic flavorings set in China (GB 10133-2005). It has been well demonstrated that the method of ID-ICP-MS coupled with Mg(OH)2 coprecipitation is suitable for determining trace Pb in fish sauces containing high levels of salt matrices. |
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Keywords: | fish sauces lead Mg(OH)2 coprecipitation isotope dilution inductively coupled plasma mass spectrometry |
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