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为了快速高效分析酸奶中的乳酸含量,研究一种新的高效液相法和手性分离柱对手性对映体L-乳酸和D-乳酸测定的方法。该检测系统配备了二极管阵列检测器的高效液相系统,检测波长为254 nm,色谱柱为手性柱Chirex 3126(D)-penicillami(4.6 mm ID×250 mm L,5μm),流动相为0.002 mol/L Cu SO4溶液(含5%异丙醇)。L-乳酸和D-乳酸的保留时间分别为25.496 min和32.864 min,4种浓度L-乳酸和D-乳酸混标保留时间的RSD为0.80%~1.30%;6次重复进样酸奶样品的L-乳酸和D-乳酸保留时间的RSD都为0.42%,L-乳酸含量的RSD为0.74%,D-乳酸含量的RSD为1.04%;在酸奶样品中加标样检测L-乳酸和D-乳酸的回收率分别为99.4%和95.0%,保留时间的RSD分别为0.20%,0.60%。将此法用于10种市售酸奶产品的检测,酸奶中L-乳酸的含量为25.00~100.00 g/L,D-乳酸的含量为0~2.00 g/L,L-乳酸的百分比在97%以上。综上所述,此法能用于分析酸奶中L-乳酸和D-乳酸,回收率高,精密度和准确性好。 相似文献
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为了快速高效分析酸奶中的乳酸含量,研究一种新的高效液相法和手性分离柱对手性对映体L -乳酸和D -乳酸测定的方法。该检测系统配备了二极管阵列检测器的高效液相系统,检测波长为254 nm,色谱柱为手性柱Chirex 3126(D)- penicillami(4.6 mm ID×250 mm L,5μm),流动相为0.002 mol/L CuSO4溶液(含5%异丙醇)。L -乳酸和D -乳酸的保留时间分别为25.496 min和32.864 min,4种浓度L -乳酸和D -乳酸混标保留时间的RSD为0.80%~1.30%;6次重复进样酸奶样品的L -乳酸和D -乳酸保留时间的RSD都为0.42%,L -乳酸含量的RSD为0.74%,D -乳酸含量的RSD为1.04%;在酸奶样品中加标样检测L -乳酸和D -乳酸的回收率分别为99.4%和95.0%,保留时间的RSD分别为0.20%,0.60%。将此法用于10种市售酸奶产品的检测,酸奶中L -乳酸的含量为25.00~100.00 g/L,D -乳酸的含量为0~2.00 g/L,L -乳酸的百分比在97%以上。综上所述,此法能用于分析酸奶中L -乳酸和D -乳酸,回收率高,精密度和准确性好。 相似文献
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Dairy herd improvement (DHI) could provide accurate and reliable information for pasture,which could be helpful for the management of herds.This paper analyzed the indicators of DHI,and based on DHI data from February 2012 to December 2012 of a dairy farm in South China, this paper performed trend analysis for milk fat rate,milk protein rate,milk lactose rate,the number of somatic cell and daily milk yield and make correlation analysis of factors of daily milk yield by gray relational model.The results showed that the milk production from February to October was declined,which showed that the rearing environment of herds was poor.The milk lactose rate,milk protein rate and milk fat rate were increased,which showed that the diet structure was reasonable and the dietary dry matter was adequate.The somatic cell count was less than 500000/mL,which showed that the incidence of mastitis was lower and the herds were in good health. The number of somatic cell was also the most influential factor of the daily milk yield,and there was a very strong negative correlation among them.Therefore,strengthening the management of cattle rearing environment,improving the level of breeding cattle breeding,adjusting the dietary nutrition structure and doing mastitis detection and prevention were very important for dairy managers. 相似文献
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