A compound-specific chlorine/bromine isotope analysis (Cl-/Br-CSIA) method was developed using gas chromatography-quadrupole mass spectrometry for polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs), which are toxic to human health and are frequently detected in various abiotic and biotic media. For PCB congeners, the molecular ion method for a concentration of 0.5–10.0 ppm, a dwell time of 20–100 ms, a relative EM voltage of 200 V, an electric current of 34 μA, and an ionization energy of 70 eV was determined as the most suitable scheme, which obtained standard deviations (SDs) of chlorine isotope ratios ranging from 0.00008 to 0.00068. As for the PBDE congeners, the lowest SDs, ranging from 0.00050 to 0.00172, were determined using the top four ion method with a concentration of 5–10 ppm and a dwell time of 20–50 ms. Both the chlorine and bromine isotope ratios showed strong concentration dependencies. Therefore, external standardization or detecting chlorine and bromine isotope ratios at a uniform concentration level is necessary to eliminate the concentration effect. In addition, ¹³C-correction is critical to remove interference from carbon isotopes. This newly developed Cl-/Br-CSIA method successfully determined the chlorine/bromine isotope ratios of PCBs/PBDEs in technical mixtures and traced the chlorine/bromine isotope ratio variations of PCBs/PBDEs in photodegradation experiments, thereby suggesting that it is a promising tool for assessing the sources and transformation processes of PCBs and PDBEs in the environment.

使用气相色谱-四极杆质谱法开发了多氯联苯（PCB）和多溴联苯醚（PBDEs）的化合物特有的氯/溴同位素分析（Cl- / Br-CSIA）方法，它们对人体健康有毒且经常发生在各种非生物和生物介质中检测到。对于PCB同类产品，确定了浓度为0.5–10.0 ppm，驻留时间为20–100 ms，相对EM电压为200 V，电流为34μA，电离能为70 eV的分子离子方法。作为最合适的方案，该方法获得的氯同位素比的标准偏差（SDs）为0.00008至0.00068。对于多溴二苯醚同类物，使用顶部四离子法测定的最低SD范围为0.00050至0.00172，浓度为5-10 ppm，停留时间为20-50 ms。氯和溴同位素比率均显示出强烈的浓度依赖性。因此，需要进行外部标准化或以均匀的浓度水平检测氯和溴同位素比，以消除浓度效应。此外，¹³ C校正对于消除碳同位素的干扰至关重要。这种新开发的Cl- / Br-CSIA方法成功地确定了工业混合物中PCBs / PBDEs的氯/溴同位素比，并在光降解实验中追踪了PCBs / PBDEs的氯/溴同位素比变化，从而表明它是一种很有前途的工具用于评估环境中PCB和PDBE的来源和转化过程。