通过式固相萃取/超高效液相色谱-串联质谱法测定鸡蛋中氯霉素、氟苯尼考和氟苯尼考胺残留

目的 建立Captiva EMR-Lipid直通式固相萃取净化，超高效液相串联三重四级杆质谱检测鸡蛋内氯霉素类药物残留的技术。方法 样品用氨化乙腈提取，提取液经Captiva EMR-Lipid柱净化，通过电喷雾离子源，正负离子同时扫描的多反应监测模式进行检测，用内标法定量。结果 在线性范围0.03～6.0μg/L内，3种化合物相关系数（r）皆在0.995以上，检出限氟苯尼考胺（FFA）、氟苯尼考（FF）与氯霉素（CAP）分别是0.04、0.01与0.02μg/kg，定量限分别是0.12、0.03与0.06μg/kg，回收率范围在92.3%～109.6%之间，相对标准偏差（n=6）范围为1.4%～8.2%。结论 此法易于操作，可实现较高准确度，适用于测定鸡蛋内FFA、FF与CAP残留。     

Optimization of pickling and annealing parameters in cold rolling using the Taguchi method

In this study, the optimum values of pickling and annealing parameters in cold rolling were obtained by using the Taguchi method. The materials taken from the hot rolling mill were subjected to pickling with different pickling times (3 min, 4 min, 5 min) parameters and then cold rolled. After this process, annealing was carried out with different annealing temperatures (700 °C, 750 °C, 800 °C), annealing times (5 min, 7.5 min, 10 min) in order to eliminate the cold working hardness. After these processes, sheet materials were subjected to skin-pass rolling, which is the last step of the rolling process. Optimum conditions are minimum rolling force measured from the load cell positioned on the work rolls. In this direction, S/N ratios with objective function “smaller is better” and were calculated and the optimum levels of the parameters were determined as 3 min pickling time, 750 °C annealing temperature and 10 min annealing time. In line with the findings obtained from the analysis of variance, it was determined that the most important parameter was the annealing time with a rate of 48.99 %. Confirmation experiments were carried out and it was concluded that the optimization was valid.