气相色谱-质谱法测定葡萄酒用软木塞中2,4,6-三氯苯甲醚的不确定度评定

建立了梯度淋洗-离子色谱-积分脉冲安培检测法同时测定运动饮料中20种氨基酸和6种糖的分析方法。通过对梯度淋洗条件、色谱柱温度、pH以及前处理条件等实验影响因素的考察，优化出适合同时检测26种组分的分析方法。结果表明，样品经调节pH沉淀蛋白后，再由RP净化柱处理，采用多级梯度淋洗模式，在35 ℃的色谱柱温度和样品溶液pH值为5.2～6.7条件下进行分离检测，26种组分在0.5～50.0 mg/L质量浓度范围内线性良好，相关系数（R2）为0.990～0.999，检出限为0.001～0.060 mg/L，定量限为0.003～0.200 mg/L。加标试验分别添加1 mg/L，10 mg/L和50 mg/L 3个水平，加标回收率达到86.2%～105.0%（n=5），相对标准偏差（RSD）为1.9%～5.3%。该方法高效、简便、灵敏、准确，可用于运动饮料中多种氨基酸和糖的同时测定分析。

Uncertainty evaluation for the determination of 2,4,6-trichloroanisole in cork by GC-MS

Uncertainty analysis was performed for the determination of releasable 2,4,6-trichloroanisole in cork used for wine by solid phase microextraction(SPME) and GC-MS. Based on CNAS-GL006:2019 Guidelines for the evaluation of uncertainty in chemical analysis and JJF 1059.1—2012 Evaluation and representation of measurement uncertainty, the mathematical model of uncertainty evaluation was constructed, the sources of uncertainty were analyzed, and the components were quantified and synthesized. The evaluation results showed that the uncertainty mainly came from the preparation process of standard solution series, followed by the additive process of internal standard substance. Furthermore, when the migration amount of 2,4,6-trichloroanisole in the cork was 2.04 ng/L, its extended uncertainty was 0.26 ng/L (k=2).