【摘要】 总氧化前体物分析（TOP assay）是评估全氟或多氟烷基化合物（PFAS）前体物总量的分析方法，但因基质干扰和超短链PFAS（C<4）检测缺失存在稳定性差和总量被低估等问题，有待进一步优化。该文考察了热活化温度、热活化时间、共存有机物、氧化剂及碱用量对TOP法氧化效率的影响，最终确定实际水样分析条件为在60 mmol/L K₂S₂O₈、150 mmol/L NaOH下85℃氧化4 h。在缩短1/3氧化时间的前提下，实现了黄腐酸质量浓度为250 mg/L的水样中PFAS前体物的彻底氧化，且实际应用效果良好。此外，为准确评估PFAS前体物总量，应考虑更多全氟烷基酸浓度的变化，例如将超短链PFAS纳入氟调聚磺酸产物评估，可缩小6.1%～58.1%的产率缺失；将与全氟磺酰胺具有相同碳数的全氟烷基磺酸纳入其产物进行评估，产率缺失缩小6.3%～10.0%。更多还原

【Abstract】 The total oxidizable precursor（TOP） assay is an analytical method for evaluating the total amount of precursors of per-and polyfluoroalkyl substances（PFAS）. However,due to the matrix interference and non-analysis of ultra-short chain PFAS（C<4）,there are still some problems in the current TOP assay,such as poor stability and underestimation of the total amount of precursors,which needs further study. Therefore,our research investigated the effects of some critical parameters in the TOP assay,such as thermal activation temperature and time,the amount of oxidant and alkali,and the coexistence of organic compounds,on the oxidation efficiency of typical precursors. The oxidation conditions for real water samples are optimized as follows. The concentrations of K₂S₂O₈ and NaOH were at 60 mmol/L and 150 mmol/L,respectively. The oxidation temperature and time were 85 ℃ and 4 hours. Under the premise of shortening one-third of the oxidation time,the good performance was obtained for the oxidation of PFAS precursors in water samples containing 250 mg/L fulvic acid. In addition,we can make a conclusion that as many PFAS as possible should be considered as the degradation products in order to accurately evaluate the total amount of PFAS precursors. For example,if the ultra-short chain PFAS were included as the target compounds,the gap of conversion yield could be reduced by 6. 1%-58. 1% for fluorotelomer sulfonate. Similarly,if the perfluoroalkyl sulfonic acids with the same carbon number as perfluorosulfonamides was included into their degradation products for the evaluation,the yield loss was reduced by 6. 3%-10. 0%.更多还原