Flores-Ramírez R, Ortiz-Pérez M D, Batres-Esquivel L, Castillo C G, Ilizaliturri-Hernández C A, Díaz-Barriga F
Centro de Investigación Aplicada en Ambiente y Salud, CIACYT-Medicina, Universidad Autónoma de San Luis Potosí, Av. Sierra Leona 550, CP 78210 San Luis Potisí, S.L.P., Mexico.
Departamento de Bioquímica, Facultad de Medicina, Universidad Autónoma de San Luis Potosí, Av. Venustiano Carranza 2405, CP 78210 San Luis Potosí, S.L.P., Mexico.
Talanta. 2014 Jun;123:169-78. doi: 10.1016/j.talanta.2014.02.023. Epub 2014 Feb 18.
A simple and rapid headspace solid-phase microextraction (HS SPME) based method is presented for the determination of Persistent Organic Pollutants (POPs) in human serum by gas chromatography (GC) coupled to mass detector (MS) with electron impact ionization (EI). As an outcome of the assessment of several polymer phases; the one with the best result was the PDMS fiber (100 μm). A multivariate analysis of variance by permutations (PERMANOVA) was performed to establish the optimal extraction conditions as a function of temperature and time variables. The results were 1 mL serum+200 µL H2SO4 9M+1 mL of deionized water at 600 rpm with a temperature of 80°C for 50 min to expose the fiber. The limits of detection (LOD) for POPs pesticides fell within the 0.22-5.41 ng/mL interval, and within 0.07-1.79 ng/mL for PCBs; a linear method was used with correlation coefficients (r) higher than 0.99. Recovery percentages at low concentrations (15 ng/mL) were 67.8-120.2%, and at high concentrations (75 ng/mL) 80.2-119.2%. Evaluated precision as percentage Relative Standard Deviation (RSD%) of repeatability and reproducibility was within a range of 0.5-9% and 0.3-21%, respectively. This analytical method prevents some of the main problems for quantifying POPs in human serum, such as the elimination of the solvents, sample handling, integration of extraction steps, pre-concentration and introduction of samples; consequently, the time and cost of analyzing the sample can be significantly reduced. The method developed was applied to determine exposure to POPs in samples of children living in different polluted sites in Mexico. In children living in indigenous communities results show exposure to DDE (median 29.2 ng/mL range 17.4-52.2 ng/mL) and HCB (median 2.53 ng/mL range 2.50-2.64 ng/mL); whereas in the industrial scenario, exposure to HCB (median 2.81 ng/mL range 2.61-3.4 ng/mL) and PCBs (median Σ-PCBs 22.2 ng/ml range 8.2-74.6 ng/mL) and finally in petrochemical scenario was demonstrated exposure to HCB (median 2.81 ng/mL range 2.61-3.4 ng/mL) and PCBs (Σ-PCBs median 7.9 ng/mL range 5.4-114.5 ng/mL).
本文提出了一种基于顶空固相微萃取（HS SPME）的简单快速方法，用于通过气相色谱（GC）与电子轰击电离（EI）质谱检测器（MS）联用测定人血清中的持久性有机污染物（POPs）。作为对几种聚合物相评估的结果，效果最佳的是聚二甲基硅氧烷（PDMS）纤维（100μm）。通过排列进行多变量方差分析（PERMANOVA），以确定作为温度和时间变量函数的最佳萃取条件。结果为1 mL血清 + 200 µL 9M硫酸 + 1 mL去离子水，在600 rpm转速、80°C温度下搅拌50分钟以使纤维暴露。POPs农药的检测限（LOD）在0.22 - 5.41 ng/mL范围内，多氯联苯（PCBs）的检测限在0.07 - 1.79 ng/mL范围内；采用线性方法，相关系数（r）高于0.99。低浓度（15 ng/mL）时的回收率为67.8 - 120.2%，高浓度（75 ng/mL）时为80.2 - 119.2%。评估的精密度以重复性和再现性的相对标准偏差（RSD%）百分比表示，分别在0.5 - 9%和0.3 - 21%范围内。这种分析方法避免了人血清中POPs定量的一些主要问题，如溶剂去除、样品处理、萃取步骤整合、预浓缩和样品引入；因此，可以显著降低样品分析的时间和成本。所开发的方法用于测定生活在墨西哥不同污染地区儿童样本中的POPs暴露情况。在生活在土著社区的儿童中，结果显示暴露于滴滴涕（DDE）（中位数29.2 ng/mL，范围17.4 - 52.2 ng/mL）和六氯苯（HCB）（中位数2.53 ng/mL，范围2.50 - 2.64 ng/mL）；而在工业场景中，暴露于HCB（中位数2.81 ng/mL，范围2.61 - 3.4 ng/mL）和PCBs（Σ - PCBs中位数22.2 ng/ml，范围8.2 - 74.6 ng/mL），最后在石化场景中，证明暴露于HCB（中位数2.81 ng/mL，范围2.61 - 3.4 ng/mL）和PCBs（Σ - PCBs中位数7.9 ng/mL，范围5.4 - 114.5 ng/mL）。
