[Laboratory analysis and its variety for sodium in prepackaged foods in China]

To observe the lab variety of sodium analysis of prepackaged from different labs of China.

Fourteen foods from seven kinds of foods were selected as food samples, including cereal products, bean products, meat products, dairy products, beverages, nuts, snacks, according to national prepackaged foods consumption survey results in 2000. The sodium concentrations were analyzed parallelly for three times by national standard methods in seven labs in China.

The 78.6% results were up to grade by Grubbs, Cochran and Dixon screening methods. The accuracy of protein analysis was expressed by variety co efficiency (C. V%). The C. V% of inner labs was from 2.46% to 7.82%. Besides walnut (with very low sodium content), the C. V% of inter labs and total labs were from 6.40% to 51.86% and from 6.88% to 52.16% (average 24.60%). The relative expanded uncertainty of protein detection was from 12.66% to 96.16% (average 46.02%).

Sodium analysis in labs in China were fit for national standards. If sodium labeling were focused on middle and high sodium contents prepackaged foods, the uncertainty of analysis could be controlled in 50%. The sodium detection level of labs in China should be promoted that the analysis variety of low content food could be reduced.