自动电位滴定计在食品检验中的应用

酱油(固体酱油)、酱类、食醋中的总酸和氨基氮的测定,都是酸碱中和法。此类调味品颜色深,加指示剂滴定,难以观察终点,只好用活性炭脱色进行测定。这样增加了操作步骤,并给结果带来误差。如能用自动电位滴定计来测定,以上存在的问题都可以得到解决,尤其在大量样品的调查中既快又准。我站自1984年以来采用PHS—1型+DK—1型+Dz—1型自动电位滴定计,测定调味品中的总酸和氨基氮,现将情况介绍如下:

甲壳素脱乙酰度的自动电位滴法测定的研究

甲壳素脱乙酰度的自动电位滴法测定的研究郭明，张晓辉，陈立平，邢晓峰甲壳素脱乙酰度Ｄ·Ｄ是鉴定壳聚糖及其衍生物产品质量的一个重要指标．Ｄ·Ｄ定义为甲壳素分子中脱除乙酰基的链节数占总链节的百分数。Ｄ·Ｄ的大小直接影响亮聚糖的物化性能，加溶解性、粘度、离子...

Study on the Determination Conditions of Lipase Activity and the Effects of Commercial Detergent Products

The activity of lipase was determined by alkaline titration method and the conditions for the determination of lipase activity were studied. The results showed that the lipase activity was stable when the volume fraction of olive oil was 25% and the temperature was at 40℃ with PH=7.5. Under the proper conditions, the effects of anionic and nonionic surfactants were investigated. The effect of nonionic surfactants on the activity of lipase was less than that of anionic surfactants. Finally, the analysis method was used to determine the activity of the lipase in the commercial detergent products. The results showed that the method can be used for the determination of lipase activity in both liquid detergent and laundry powder. However, the temperature and pH value of the detergent solution should be controlled strictly during the conduction of the determination.