高效液相色谱法测定聚乳酸吸管中甲醛迁移量

目的：建立用于准确检测聚乳酸吸管中甲醛在水和酸性食品模拟液中迁移量的检测方法。方法：优选的色谱条件为：流动相水—乙腈（V_水∶V_乙腈为55∶45），柱温35 ℃，检测波长355 nm。优化的柱前衍生条件：酸性2,4-二硝基苯肼溶液中冰乙酸体积分数为1.5 mL/100 mL（pH 3.07），2,4-二硝基苯肼用量为甲醛物质的量的4倍，反应温度为45 ℃，反应时间为40 min。结果：衍生化产物甲醛-2,4-二硝基苯腙标准溶液在1.008～70.560 μg/mL的范围内线性方程为y=55.247 0x-3.849 4，相关系数为0.999 5；对应的甲醛检出限为0.066 mg/kg，定量限为0.22 mg/kg，且衍生化产物甲醛-2,4-二硝基苯腙在13.5 h内稳定；甲醛三水平加标试验的平均回收率在92.6%～104.1%，标准偏差（n=6）在0.4%～3.3%。在迁移温度为5，40，100 ℃，迁移时间为3 h的试验条件下，甲醛从一次性聚乳酸吸管到3种食品模拟液（水、3%冰乙酸水溶液、4%冰乙酸水溶液）的最大迁移量为1.839 mg/kg，小于中国及欧盟规定的15 mg/kg的特定迁移量要求。结论：该方法准确、高效，适用于聚乳酸吸管中甲醛迁移量的检测。

Migration quality of formaldehyde in the polylactic acid straw detected by HPLC

Objective: A formaldehyde detection method was established for the accurate analysis of the migration of formaldehyde in water and acid simulants from the polylactic acid straws. Methods: The preferred chromatographic conditions were: mobile phase water-acetonitrile (V_water∶V_acetonitrile of 55∶45), column temperature of 35 ℃, detection wavelength of 355 nm. The optimized 2,4-dinitrophenylhydrazine derivative conditions were: the acetic acid in acidic 2,4-dinitrophenylhydrazine solution of 1.5 mL/100 mL (pH 3.07), the molar ratio of 2,4- dinitrophenylhydrazine of quadruple formaldehyde, the reaction temperature of 45 ℃, and the reaction time of 40 min. Results: The linear equation of formaldehyde-2,4-dinitrobenzene was y=55.247 0x-3.849 4 within 1.008 to 70.560 μg/mL, with the correlation coefficient of 0.999 5. The detection limit of the corresponding formaldehyde was 0.066 mg/kg, and the quantification limit of which was 0.22 mg/kg. The formaldehyde-DNPH was stable within 13.5 hours. The average recovery of simulants spiking with formaldehyde in 3 levels was from 92.6% to 104.1%, with SD (n=6) of 0.4% to 3.3%. The maximum migration of formaldehyde from disposable polylactic acid straws to three food simulants (water, 3% acetic acid solution, 4% acetic acid solution) was 1.839 mg/kg, less than the specific migration requirement of 15 mg/kg stipulated by China and the European Union. Conclusion: This method is accurate and efficient enough to apply for the analysis of formaldehyde migration from polylactic acid straws.