固相萃取-高效液相色谱法测定某水库型水源地微囊藻毒素

采用优化的固相萃取一高效液相色谱法对某水库型水源地微囊藻毒素污染进行了为期1年的监测,同时测定了相关的水质指标和藻类种群结构。结果表明：该水库在春末和夏、秋季检出了3种微囊藻毒索（MC—YR、MC—RR、MC—LR）,以MC—YR为主,夏季是藻毒素污染的高峰时段,其浓度与水库环境条件、藻类生物量有密切的关系。     

兽药中间体氟尼辛的高效液相色谱分析

为了监控兽药的质量,建立测定兽药中间体氟尼辛的高效液相色谱分析方法。适宜的分析条件为:色谱柱为250×4.6mm不锈钢柱,内装C18键合硅胶填料;流动相:v(甲醇)∶v(水,pH调至为4.0)=82∶18;流速:1.0mL/min;紫外检测器,检测波长为254nm。测定方法的标准偏差、变异系数分别为0.217、0.0022,平均回收率为100.1%。     

仿真结果检验和因子分析的两步仿真法

建立多状态两步仿真检验法,可以对均值仿真结果进步检验,确定仿真结果与试验结果之间的误差是由于随机因素引起的偶然误差,还是由于仿真不正确引起的系统误差,进而判断仿真结果正确与否.同时提出多因子两步仿真分析法,能够对仿真结果的各个影响因素(因子)逐一进行分析,并确定哪些因素已被正确仿真,哪些因素尚未被正确模拟,从而指导仿真软件的编制和仿真结果的修正.文中方法适用于正态分析、非正态分布以及形式未知的情况,且事先不必对工程实际中遇到的随机变量分布作任何假设,具有精度高的特点.     

辣椒、番茄中氟虫脲残留量的HPLC分析方法

建立了测定辣椒和番茄中氟虫脲残留量的高效液相色谱法。色谱柱为ThermoHypersil-ODSC18D250mm×4.6mm;流动相:甲醇∶水(80∶20,v∶v);流速:1.0ml/min;检测波长:254nm。试样用丙酮提取,二氯甲烷萃取,中性氧化铝柱净化,外标法定量。在0.05￣0.5mg/kg的添加浓度下,平均回收率为87.51%￣102.13%,变异系数为0.07%￣6.02%,仪器最低检出限为8.809×10-10g,最小检出浓度0.011mg/kg,该方法的准确度、精密度及灵敏度均满足农药残留分析的要求。     

72%霜脲·锰锌WP中霜脲氰的高效液相色谱分析

采用高效液相色谱法分析复配杀菌剂72%霜脲·锰锌WP中的霜脲氰含量,该法简便、快捷、准确。试样溶解于甲醇,试样中霜脲氰在150mm×4.6mm(i.d.)C18不锈钢柱(装填YWG)中,流动相:甲醇与水的体积比为40∶60,采用紫外检测器,在UV254nm下,进行分离和测定。方法的标准偏差为0.075,变异系数为0.94%,回收率在99.01%～100.11%之间,线性相关系数为0.9998。     

色酚AS的高效液相色谱分析

本文采用高效液相色谱法,峰面积外标定量对色酚AS及其有机杂质进行了分离。通过对流动相、色谱柱、检测波长法的选择确定了最佳的分离条件。该方法具有较好的准确度和精密度     

高效液相色谱法定量分析C.I.酸性蓝9隐色体中苯甲醛邻磺酸的含量

本文阐述了C．I．酸性蓝9隐色体中苯甲醛邻磺酸的高效液相色谱定量分析方法,采用Lichrospher C18色谱柱,以甲醇／醋酸／水的体积比率为20：0．2：80为流动相,检测波长为254nm,线性范围量0～0．52mg／mL（r=0.9991）,相对标准偏差为0．28％,回收率为99．01％-100．44％。     

二硫氰基甲烷的高效液相色谱分析方法

文章建立了一种利用反相高效液相色谱测定二硫氰基甲烷含量的方法。色谱柱为C18反相柱,流动相为60/40(体积比)的乙腈/水,柱温为室温,流速为0.9 mL/min。采用外标法定量。实验结果表明,该方法的标准偏差为0.27%,变异系数为0.28%,平均回收率为99.6%,线性相关系数为0.9999,呈良好的线性关系,该方法操作简单、快速、准确,是用于生产控制的较理想的测定方法。     

喹禾糠酯原药的高效液相色谱分析

采用高效液相色谱法对喹禾糠酯的总酯含量进行分析,流动相为乙腈-水(体积比为7:3),使用Hypersil C18色谱柱和具有可变波长的紫外检测器.该方法的标准偏差为0.29%,变异系数为0.32%,回收率为99.56%,线性相关系数为O.9999.     

Variation of aflatoxin M1 contamination in milk and milk products collected during winter and summer seasons

Total 221 samples of milk and milk products were collected during winter (November 2011–February 2012) and 212 samples were collected during summer (May–August 2012) from central areas of Punjab, Pakistan. The samples were analyzed for the presence of aflatoxin M₁ (AFM₁) with a validated HPLC method equipped with florescence detector. The results revealed that from winter season almost 45% samples of milk and milk products were found to be contaminated with AFM₁ i.e. 40% of raw milk, 51% of UHT milk, 37% of yogurt, 60% of butter and 43% of ice cream samples and 27, 24, 25, 34 and 17% of samples were found above the recommended limit for AFM₁, respectively. However, from summer season 32% samples of milk and milk products were found to be contaminated i.e. 36% of raw milk, 31% of UHT milk, 29% of yogurt, 40% of butter and 24% of ice cream and 23, 23, 18, 20 and 5% of samples were found above the permissible limit for AFM₁, respectively. The levels of contamination in winter milk and milk product samples were significantly higher (α ≤ 0.05) than in summer season. The occurrence of AFM₁ in milk and milk products were higher, demanding to implement strict regulations and also urged the need for continuous monitoring of milk and milk products in order to minimize the health hazards.