Ahmadvand Mohammad, Sereshti Hassan, Parastar Hadi
Department of Chemistry, Faculty of Science, University of Tehran, Tehran, Iran.
Department of Chemistry, Faculty of Science, University of Tehran, Tehran, Iran.
J Chromatogr A. 2015 Sep 25;1413:117-26. doi: 10.1016/j.chroma.2015.08.026. Epub 2015 Aug 15.
In the present research, ultrasonic-assisted emulsification-microextraction (USAEME) coupled with gas chromatography-mass spectrometry (GC-MS) has been proposed for analysis of thirteen environmental protection agency (EPA) polycyclic aromatic hydrocarbons (PAHs) in aqueous samples. Tetrachloroethylene was selected as extraction solvent. The main parameters of USAEME affecting the efficiency of the method were modeled and optimized using a central composite design (CCD). Under the optimum conditions (9μL for extraction solvent, 1.15% (w/v) NaCl (salt concentration) and 10min for ultrasonication time), preconcentration factor (PF) of the PAHs was in the range of 500-950. In order to have a comprehensive analysis, multivariate curve resolution-alternating least squares (MCR-ALS) as a second-order calibration algorithm was used for resolution, identification and quantification of the target PAHs in the presence of uncalibrated interferences. The regression coefficients and relative errors (REs, %) of calibration curves of the PAHs were in the satisfactory range of 0.9971-0.9999 and 1.17-6.59%, respectively. Furthermore, analytical figures of merit (AFOM) for univariate and second-order calibrations were obtained and compared. As an instance, the limit of detections (LODs) of target PAHs were in the range of 1.87-18.9 and 0.89-6.49ngmL(-1) for univariate and second-order calibration, respectively. Finally, the proposed strategy was used for determination of target PAHs in real water samples (tap and hookah waters). The relative recoveries (RR) and the relative standard deviations (RSDs) were 68.4-109.80% and 2.15-6.93%, respectively. It was concluded that combination of multivariate chemometric methods with USAEME-GC-MS can be considered as a new insight for the analysis of target analytes in complex sample matrices.
在本研究中，已提出将超声辅助乳化微萃取（USAEME）与气相色谱 - 质谱联用（GC - MS）用于分析水样中的13种美国环境保护局（EPA）多环芳烃（PAHs）。选择四氯乙烯作为萃取溶剂。使用中心复合设计（CCD）对影响该方法效率的USAEME主要参数进行建模和优化。在最佳条件下（萃取溶剂9μL，1.15%（w/v）NaCl（盐浓度），超声时间10分钟），PAHs的预浓缩因子（PF）在500 - 950范围内。为了进行全面分析，采用多元曲线分辨交替最小二乘法（MCR - ALS）作为二阶校准算法，用于在存在未校准干扰的情况下对目标PAHs进行分辨、鉴定和定量。PAHs校准曲线的回归系数和相对误差（REs，%）分别在令人满意的0.9971 - 0.9999和1.17 - 6.59%范围内。此外，还获得并比较了单变量和二阶校准的分析性能指标（AFOM）。例如，目标PAHs的检测限（LODs）对于单变量校准在1.87 - 18.9 ng mL⁻¹范围内，对于二阶校准在0.89 - 6.49 ng mL⁻¹范围内。最后，将所提出的策略用于测定实际水样（自来水和水烟用水）中的目标PAHs。相对回收率（RR）和相对标准偏差（RSDs）分别为68.4 - 109.80%和2.15 - 6.93%。得出的结论是，多元化学计量学方法与USAEME - GC - MS的结合可被视为分析复杂样品基质中目标分析物的一种新方法。
