Abstract:Through investigating the contents of heavy metals arsenic (As), cadmium (Cd), chromium (Cr), lead (Pb), and mercury (Hg) in tsamba produced by different grinding methods in four cities in Tibet (Shannan, Xigaze, Nyingchi and Lhasa), and conducting a comprehensive analysis and evaluation of pollution levels, reliable data support could be provided to enhance the quality and safety level of tsampa production and strengthen quality and safety supervision. A total of 101 samples of tsamba produced in different modes were collected from four cities in Tibet. And inductively coupled plasma mass spectrometry was utilized to detect and analyze five heavy metals in tsamba samples, and to evaluate their quality and safety. Among 101 tsamba samples evaluated using the comprehensive pollution index of tsamba quality grading standard, both electric mill and water mill methods yielded safe levels of heavy metals including As, Cd, Cr, Pb, and Hg in tsamba, based on the evaluation results of single factor pollution index and comprehensive pollution index in the production of tsamba prepared by different grinding methods. Based on the evaluation results of the single factor pollution index and comprehensive pollution index in the production of tsamba in different cities, it could be concluded that the heavy metal Pb in tsamba in Shannan city is basically clean, and As, Cd, Cr, and Hg are all safe. The heavy metal As in tsamba in Xigaze city is basically clean, and Cd, Cr, Pb, and Hg are all safe. The heavy metal Pb in tsamba in Nyingchi city is basically clean, and As, Cd, Cr, and Hg are all safe. The heavy metals Pb, As, Cd, Cr, and Hg in tsamba in Lhasa city are all safe. According to the Nemerow comprehensive pollution level evaluation, the comprehensive pollution index levels of other heavy metals in the four cities are all safe. Therefore, the comprehensive pollution index levels of heavy metals such as As, Cd, Cr, Pb, and Hg in tsamba in four cities of Tibet are all safe.
