稀释倍数对食品包装纸中高锰酸钾消耗量的影响

目的研究稀释倍数对食品包装纸中高锰酸钾消耗量测定结果的影响。方法样品经浸泡前处理后,采用滴定法对多个试样不同稀释倍数下的高锰酸钾消耗量进行测定,进而确定不同滴定体积试样的稀释范围。结果滴定体积大于10 mL的试样,需要稀释5倍以上;滴定体积在9～10 mL之间的试样,需要稀释2～5倍;滴定体积7～9 mL之间的试样稀释需要1～2倍。滴定体积在约9 mL的试样稀释不得超过5倍,滴定体积约10 mL的试样稀释不得超过10倍,滴定体积在7～9 mL之间的试样稀释不得超过4倍。结论煮沸时出现褪色现象的试样需要稀释后测定,稀释倍数对高锰酸钾消耗量影响很大,要选择合适的稀释倍数才能测得准确的结果。

Effect of dilution multiples on consumption of potassium permanganate in food packaging paper

Objective To study the effect of dilution multiples on the determination of potassium permanganate consumption in food packaging paper. Methods Samples were soaked and then the consumption of potassium permanganate at different dilution multiples of different samples were measured by titration method to determine the dilution range of different titration volumes of samples. Results Samples with a titration volume greater than 10 mL should be diluted more than 5 times, samples with a titration volume between 910 mL should be diluted 25 times, samples with a titration volume between 79 mL should be diluted 25 times. The sample with a titration volume about 9 mL should not be diluted more than 5 times, the sample with a titration volume about 10 mL should not be diluted more than 10 times, the sample with a titration volume between 79 mL should not be diluted more than 4 times. Conclusion Samples those appearing discolored during boiling need to be measured after dilution. The dilution factor has a great influence on the consumption of potassium permanganate and appropriate dilution multiples should be chosen to get the correct results.