论文部分内容阅读
牛乳中的Mg及Ca测定,通常使用三氯醋酸—EDTA过滤除去蛋白质,但三氯醋酸与EDTA方法操作烦杂,测定样品液制备需要较长的时间。本研究用硝酸与膜滤器进行前处理,破坏蛋白质与Mg及Ca的结合,然后用离子色谱(IC)分析。方法简便、快速、适用于牛乳中总Mg与Ca的测定。试剂Mg及Ca标准溶液(各500mg/L)分别以MgCl_2·6H_2及CaCl_2用蒸馏水溶解配制。EDTA溶液:用滴定法求出准确浓度,使用时稀释成适当浓度。测定条件IC仪器(日本分光产品),880—PU型高压泵;CD型电导检测器。低交换容量聚苯乙烯系阳离子交换树脂Y—512分离柱与Y—
Determination of Mg and Ca in milk, usually using trichloroacetic acid-EDTA filtered to remove protein, but trichloroacetic acid and EDTA method is complicated operation, the determination of the sample solution preparation takes a long time. In this study, pretreatment with nitric acid and membrane filters destroyed the binding of proteins to Mg and Ca, and then analyzed by ion chromatography (IC). The method is simple, rapid and suitable for the determination of total Mg and Ca in milk. The reagent Mg and Ca standard solution (each 500mg / L) were prepared by dissolving MgCl 2 · 6H 2 and CaCl 2 in distilled water respectively. EDTA solution: The titration method to find the exact concentration, when used diluted to the appropriate concentration. Measurement conditions IC instrument (Japan spectroscopy products), 880-PU high-pressure pump; CD-type conductivity detector. Low exchange capacity polystyrene cation exchange resin Y-512 separation column and Y-