Borus-Böszörményi N, Schoket B
Nahrung. 1979;23(5):537-47. doi: 10.1002/food.19790230509.
A square-wave polarographic method suitable for measuring tin in canned products and raw materials for food industry was examined. After wet digestion of the sample tin was directly determined from the acidic stock solution gained. If 10 ml of the stock solution was equivalent to 1 g sample,--varying sensitivity of the instrument--tin could be determined in the range of 5 micrograms/g--400 micrograms/g with +/- 5% relative error. By increasing sensitivity of the instrument this range could be extended to as little as 0,5 micrograms tin/g sample. The optimal quantity of hydrochloric acid to be added to the sulphuric acid solution of the digested sample before the instrumental measurement was determined by means of model solutions. Examinations concerning interference of lead were also performed. It is established, that if the ratio of Sn/Pb is at least 4/1, lead does not interfere with the polarographic tin determination. If the ratio of Sn/Pb is 2/1 or 1/1 tin content can be calculated after measuring the height of the peak of lead in sulphuric acid electrolyte. The method was applied for several canned products and comparative tests were performed with the spectrophotometric method given in the Hungarian standard MSZ 3612/7-77.
研究了一种适用于测定食品工业罐头产品和原材料中锡的方波极谱法。样品经湿消化后，直接从所得酸性储备溶液中测定锡。如果10毫升储备溶液相当于1克样品，根据仪器灵敏度的不同，锡的测定范围为5微克/克至400微克/克，相对误差为±5%。通过提高仪器灵敏度，该范围可扩展至低至0.5微克锡/克样品。通过标准溶液确定了在仪器测量前向消化样品的硫酸溶液中添加盐酸的最佳量。还进行了关于铅干扰的研究。结果表明，如果锡/铅的比例至少为4/1，则铅不会干扰极谱法测定锡。如果锡/铅的比例为2/1或1/1，则可在测量硫酸电解液中铅峰的高度后计算锡含量。该方法应用于几种罐头产品，并与匈牙利标准MSZ 3612/7 - 77中给出的分光光度法进行了对比试验。
