The identity of an unknown environmental pollutant is reflected by the mass and dissociation chemistry of its (quasi)molecular ion. Gas chromatography–atmospheric pressure chemical ionization–mass spectrometry (GC-APCI-MS) increases the yield of molecular ions (compared to conventional electron ionization) by collisional cooling. Scanning quadrupole data-independent acquisition (SQDIA) permits unbiased, unattended selection of (quasi)molecular ions and acquisition of structure-diagnostic collision-induced dissociation mass spectra, while minimizing interferences, by sequentially cycling a quadrupole isolation window through the m/z range. This study reports on the development of a suspect screening method based on industrial compounds with bioaccumulation potential. A comparison of false and correct identifications in a mixed standard containing 30 analytes suggests that SQDIA results in a markedly lower false-positive rate than standard DIA: 5 for SQDIA and 82 for DIA. Electronic waste dust was analyzed using GC and quadrupole time-of-flight MS with APCI and SQDIA acquisition. A total of 52 brominated, chlorinated, and organophosphorus compounds were identified by suspect screening; 15 unique elemental compositions were identified using nontargeted screening; 17 compounds were confirmed using standards and others identified to confidence levels 2, 3, or 4. SQDIA reduced false-positive identifications, compared to experiments without quadrupole isolation. False positives also varied by class: 20% for Br, 37% for Cl, 75% for P, and >99% for all other classes. The structure proposal of a previously reported halogenated compound was revisited. The results underline the utility of GC-SQDIA experiments that provide information on both the (quasi)molecular ions and its dissociation products for a more confident structural assignment.

中文翻译：

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气相色谱-常压化学电离-质谱法独立于可疑有机污染物的鉴定

未知环境污染物的身份通过其（准）分子离子的质量和离解化学来反映。气相色谱-大气压化学电离-质谱（GC-APCI-MS）通过碰撞冷却提高了分子离子的产量（与传统的电子电离相比）。扫描四极杆数据独立采集（SQDIA）可以通过依次使四极杆隔离窗口循环通过m / z来无偏，无人照管地选择（准）分子离子，并获取结构诊断碰撞诱发的解离质谱图，同时将干扰降至最低。范围。这项研究报告了基于具有生物蓄积潜力的工业化合物的可疑筛查方法的发展。比较包含30种分析物的混合标准品中的错误和正确标识，这表明SQDIA导致的假阳性率明显低于标准DIA：SQDIA为5，DIA为82。使用GC和具有APCI和SQDIA采集功能的四极杆飞行时间质谱仪分析了电子废物粉尘。通过可疑筛查共鉴定出52种溴，氯和有机磷化合物。使用非靶向筛选鉴定出15种独特的元素组成；与没有四极隔离的实验相比，使用标准品确认了17种化合物，将其他化合物鉴定为2、3或4的置信度。SQDIA减少了假阳性鉴定。误报率也因类别而异：Br为20％，Cl为37％，P为75％，其他所有类别均大于99％。重新讨论了先前报道的卤代化合物的结构建议。结果强调了GC-SQDIA实验的实用性，该实验可提供有关（准）分子离子及其解离产物的信息，从而使结构更可靠。