Determination of Lead Amount in Noodle Soup

Abstract

Objective: To determine amount of lead in noodle soup prepared in the old-style noodle soup boiling pot. Method: Noodle soupfrom 10 places in Muang district of Chiagmai province was sampled 3 times with one week apart. Each sample was digestedand measured for lead amount using absorbance by atomic absorption spectroscopy. Results: The method to determine leadamount in noodle soup was found to have a high linearity (r2 = 0.999) with a concentration range of 0.25 - 10 ppm, a limit ofdetection of 0.25 ppm, limit of quantitation of 1 ppm, %RSD of 4.37 - 7.6%, and % recovery of 100 – 104%. The amount oflead in the noodle soup samples ranged from 0.1 – 1.25 ppm (Table 3). The amount of lead in many samples was over the limitin food recommended by the Thai Food Act, which is 1.0 ppm. In addition to the inorganic lead from the soup pot, lead innoodle soup could come from the organic lead in flavoring agents added into the soup. Conclusion: Lead in noodle soup wasover the recommended limit. It may be harmful to consume noodle soup frequently. The source of lead in noodle soup could beinorganic (soup pot) as well as organic ones (flavoring agents).Key words: lead, noodle soupThai Pharm Health Sci J 2009;4(2):164-168§