混合模式吸附剂固相萃取-气相色谱-质谱法测定皮革中的磷酸三（2-氯乙基）酯

磷酸三（2-氯乙基）酯（TCEP）是一种皮革生产中常用的加工助剂，其具有致癌、神经毒性和生殖毒性，被欧洲化学品管理局列入禁用的第二批授权物质清单。由于皮革产品基质复杂，采用常用的固相萃取（SPE）方法提取对TCEP的回收率不高。Silica-WCX是一种自制的含有羧基与烷基的新型混合模式吸附剂。研究表明，通过在酸性条件下使其羧基保持质子化状态，能有效增强Silica-WCX对极性化合物TCEP的萃取性能，使TCEP的回收率得到明显提高。本文以Silica-WCX为SPE材料，建立了测定皮革中TCEP的SPE-GC-MS方法。该方法的线性范围为0.10~100.0 μg/L，定量限（S/N=10）为44.46 ng/kg，不同添加水平下TCEP的平均回收率在91.45%~99.98%之间，相对标准偏差（RSD）在4.33%~5.97%之间。该方法简便快捷，灵敏度高，定量限低于欧盟《化学品的注册、评估、授权和限制》（registration，evaluation，authorization and restriction of chemicals，REACH）法规的限量要求，适用于皮革及其制品中TCEP的测定。

Determination of tris(2-chloroethyl)phosphate in leather by gas chromatography-mass spectrometry coupled with mixed-mode sorbent solid phase extraction

Leather is one of the important exporting products to European Union (EU), and tris(2-chloroethyl)phosphate (TCEP) is a commonly used flame retardant in leather and leather products. Recently, TCEP has been classified as a kind of substance of very high concern (SVHC) by EU for its carcinogenicity and reproductive toxicity. But to date, there is not a recognized method for the determination of TCEP in leather and leather products due to the serious matrix interferences and relatively low recovery of TCEP. In this work, a home-made mixed-mode sorbent (Silica-WCX) with carboxyl and alkyl groups was tested as the sorbent of solid phase extraction (SPE) to extract TECP from leather. The results demonstrated that, making the carboxyl groups protonized under acidic condition, Silica-WCX exhibited better extraction performance towards TCEP over some frequently used commercial sorbents tested. After the optimization of the SPE conditions based on Silica-WCX, a method of gas chromatography/mass spectrometry (GC-MS) was established for the determination of TCEP in leather samples. The linear range for TCEP ranged from 0.10 to 100.0 μg/L and the limit of quantification (LOQ, S/N=10) was 44.46 ng/kg. The recoveries of TCEP spiked in samples at varied levels were in the range of 91.45%-99.98% with the relative standard deviations (RSDs) of 4.33%-5.97%. The method is simple, sensitive and reliable for the analysis of TCEP in leather and leather products.