Trace-level analysis of polychlorinated biphenyls,organochlorine pesticides and polycyclic aromatic hydrocarbons in human plasma or serum by dispersive liquid–liquid microextraction and gas chromatography–tandem mass spectrometry

A method to determine 8 polychlorinated biphenyls (PCBs), 23 organochlorine pesticides (OCPs) and 16 polycyclic aromatic hydrocarbons (PAHs) was described using dispersive liquid–liquid microextraction (DLLME) of a small amount of plasma or serum sample and gas chromatography–tandem mass spectrometry (GC–MS/MS). The appropriate selection of the extraction solvent and dispersing solvent contributes to a high extraction yield and a clean extract. To verify the developed method, the interference, linearity of the calibration curve, detection limit, precision and accuracy were evaluated. The calibration curves were linear by 2–3 orders of magnitude with correlation coefficients above 0.997 in all cases. The LODs of PCBs, OCPs and PAHs were measured in the ranges of 0.0006–0.0029, 0.001–0.029 and 0.0002–0.012 ng/mL. The intraday precision achieved by this method was 2.19–10.3% (PCBs), 1.65–14.3% (OCPs) and 0.91–12.8% (PAHs), and the intraday accuracy 1.56–7.37% (PCBs), 2.34–19.6% (OCPs) and 1.49–15.7% (PAHs). The advantage of this method is that the analysis of PCBs, OCPs, and PAHs can be performed in a single chromatographic run, and the low detection limit enables monitoring of target substances in low exposure general public samples, and the analysis procedure is relatively simple and fast.     

同位素稀释-高分辨气相色谱/高分辨质谱测定大气中有机氯农药

建立了测定大气中25种有机氯农药(OCPs)的同位素稀释-高分辨气相色谱/高分辨质谱法(ID-HRGC/HRMS)。样品用正己烷/二氯甲烷(1∶1, v/v)进行加速溶剂萃取(ASE)。通过柱洗脱实验、单柱和组合柱净化实验,最终确定样品的净化方案为弗罗里硅土固相萃取柱和石墨化炭黑固相萃取柱组合净化。样品萃取液净化后进行HRGC/HRMS分析。采用平均相对响应因子(RRF)法对样品中目标物进行定量,6点校准溶液RRF的相对标准偏差(RSD)均≤20%。线性范围为0.4~800 μg/L,相关系数R²均>0.992。对空白样品依次进行100 pg、400 pg和15 ng水平下的加标试验,各添加水平下OCPs测定值的RSD为0.64%~16%,加标回收率为67.2%~135%。穿透试验表明,滤膜+聚氨酯泡沫/聚氨酯泡沫作为吸附介质的大体积主动大气采样器(AAS)在采集环境空气时,五氯苯极易发生穿透,有效采样模式待进一步研究。在上述采样模式下,六氯苯的有效采样体积较小,标准状态(101.325 kPa, 273 K)采样体积应≤30 m³,其他OCPs应≤1200 m³。以上述体积计算,25种目标化合物的检出限为0.002~0.7 pg/m³。对北京环境空气样品分析测定,结果显示除反式-环氧七氯、异狄氏剂、顺式-九氯和4,4'-滴滴滴在部分样品中未检出外,其他OCPs均为100%检出;六氯苯浓度在514~563 pg/m³之间,其他OCPs的浓度在0.01~18.9 pg/m³之间;替代标回收率为33.9%~155%。由于现有相关监测标准的仪器灵敏度较低、方法检出限较高,已无法满足目前空气中痕量OCPs的测定需求,因此亟待修订新的高灵敏度监测方法标准。该方法适用于目前大气中OCPs的超痕量水平分析,为新标准的制订奠定基础,也为国家履行相关国际公约提供有力技术指导。     

Optimization and validation of organochlorine compounds in adipose tissue by SPE‐gas chromatography

Scientific evidence has shown an association between organochlorine compounds (OCC) exposure and human health hazards. Concerning this, OCC detection in human adipose samples has to be considered a public health priority. This study evaluated the efficacy of various solid‐phase extraction (SPE) and cleanup methods for OCC determination in human adipose tissue. Octadecylsilyl endcapped (C₁₈‐E), benzenesulfonic acid modified silica cation exchanger (SA), poly(styrene‐divinylbenzene (EN) and EN/RP₁₈ SPE sorbents were evaluated. The relative sample cleanup provided by these SPE columns was evaluated using gas chromatography with electron capture detection (GC–ECD). The C₁₈‐E columns with strong homogenization were found to provide the most effective cleanup, removing the greatest amount of interfering substance, and simultaneously ensuring good analyte recoveries higher than 70%. Recoveries > 70% with standard deviations (SD) < 15% were obtained for all compounds under the selected conditions. Method detection limits were in the 0.003–0.009 mg/kg range. The positive samples were confirmed by gas chromatography coupled with tandem mass spectrometry (GC‐MS/MS). The highest percentage found of the OCC in real samples corresponded to HCB, o,p′‐DDT and methoxychlor, which were detected in 80 and 95% of samples analyzed respectively. Copyright © 2012 John Wiley & Sons, Ltd.     

A Photochemistry Technique Using Ultraviolet Irradiation Followed by Gas-Liquid Chromatography to Confirm the Identity of Some Organochlorine Pesticides

Abstract

A procedure involving ultraviolet (UV) irradiation followed by gas-liquid chromatographic (GLC) detection of photodecomposition products to confirm the identity of selected organochlorine pesticides is described. The Irradiation intensity was standardized by determining the position relative to the UV source which resulted in equal GLC peak heights for the parent compound and major photo-decomposition product after 8 minutes of exposure of a solution of heptachlor epoxide in isooctane. Chromatograms showing photo-decomposition patterns for 33 compounds are presented. Observations and comments on the applicability of this technique to organo-chlorine pesticide residue confirmation are reported.     

Trace Metal and Persistent Organochlorine Levels in Wood Bison (Bison bison athabascae) from the Mackenzie Bison Sanctuary

Abstract

Tissue samples were collected from ten healthy mature female wood bison (B. bison athabascae) for examination. Livers and kidneys were tested for toxic heavy metals and trace metals considered as essential nutrients for successful reproduction, while fat samples were analyzed for persistent chlorinated hydrocarbons. No elevated levels of toxic heavy metals (arsenic, cadmium, lead, mercury) were found and essential trace elements (copper, manganese, selenium, zinc) were within the acceptable ranges established for healthy cattle. All fat samples tested contained trace levels of α-BHC (mean value, 23 ppb) and lindane (mean value, 3 ppb).     

固相萃取/气相色谱-质谱法对土壤中有机氯农药的分析及基质效应研究

建立了一种固相萃取/气相色谱-质谱法同时测定土壤中23种有机氯农药的方法,并研究了不同基质效应补偿方式。土壤样品经正己烷∶丙酮(体积比1∶1)提取,弗罗里土小柱净化,采用气相色谱-质谱仪检测。结果发现7种有机氯存在中/强程度的基质效应;在10 mL二氯甲烷∶正己烷(体积比1∶9)+10 mL丙酮∶正己烷(体积比1∶9)为固相萃取的洗脱剂,且脉冲压力为275.8 kPa条件下,可将23种有机氯的基质效应均控制在20%以内。23种有机氯农药在0.4～10μg·mL~(-1)质量浓度范围内线性良好,相关系数(r~2)均不小于0.999 2,检出限为1.0～8.6μg·kg~(-1),定量下限为4.0～34.4μg·kg~(-1);在20、60、100μg·kg~(-1)3个加标水平下空白土壤中的平均回收率为46.3%～127%,相对标准偏差(n=6)为0.68%～15%。采用该方法在某土壤样品中检出α-六六六、γ-六六六、p,p′-DDE、异狄氏剂醛、p,p′-DDT 5种有机氯农药。     

A three‐phase solvent extraction system combined with deep eutectic solvent‐based dispersive liquid–liquid microextraction for extraction of some organochlorine pesticides in cocoa samples prior to gas chromatography with electron capture detection

A sample pretreatment method based on the combination of a three‐phase solvent extraction system and deep eutectic solvent‐based dispersive liquid–liquid microextraction has been introduced for the extraction of four organochlorine pesticides in cocoa samples before their determination by gas chromatography‐electron capture detection. A mixture of sodium chloride, acetonitrile, and potassium hydroxide solution is added to cocoa bean or powder. After vortexing and centrifugation of the mixture, the collected upper phase (acetonitrile) is removed and mixed with a few microliters of N,N‐diethanol ammonium chloride: pivalic acid deep eutectic solvent. Then it is rapidly injected into deionized water and a cloudy solution is obtained. Under optimum conditions, the limits of detection and quantification were found to be 0.011‐0.031 and 0.036‐0.104 ng/g, respectively. The obtained extraction recoveries varied between 74 and 92%. Also, intra‐ (n = 6) and interday (n = 4) precisions were less than or equal to 7.1% for the studied pesticides at a concentration of 0.3 ng/g of each analyte. The suggested method was applied to determine the studied organochlorine pesticide residues in various cocoa powders and beans gathered from groceries in Tabriz city (Iran) and aldrin and dichlobenil were found in some of them.     

气相色谱-质谱法同时测定地下水中42种半挥发性有机污染物

建立了同时测定地下水中多环芳烃(PAHs)、多氯联苯(PCBs)、有机氯农药(OCPs)和有机磷农药(OPPs)等42种半挥发性有机污染物的分析方法,对固相萃取、液-液萃取、萃取溶剂和色谱柱等分析条件进行优化。最终采用乙酸乙酯-正己烷(1∶4)液液萃取,DB-5MS色谱柱分离,GC-MS/SIM测定,内标法定量。结果表明,42种目标物在0.5~1 000μg/L范围内线性关系良好(r20.995);方法检出限为0.05~3.08 ng/L。在10、40、400 ng/L加标水平下,42种目标物的基体加标平均回收率为73.0%~107%,相对标准偏差(RSD,n=5)为1.4%~11.3%。将方法应用于石家庄周边地区水样检测,结果可靠。该方法灵敏、准确、简单易行,可显著提高地下水中主要有机污染物的分析效率。     

气相色谱-柱后分流-反吹技术测定含脂羊毛中有机氯和有机磷类杀虫剂残留

建立了同时测定含脂羊毛中20种有机氯和有机磷类杀虫剂残留的气相色谱-柱后分流-反吹检测方法.通过二氧化碳超临界萃取技术提取含脂羊毛样品中的杀虫剂残留并经中性氧化铝固相萃取柱净化,采用气相色谱-柱后分流技术,可以同时得到3个检测器信号(MSD、μECD和NPD),可对两类杀虫剂准确定性和定量分析.同时运用反吹技术,减少样品中高沸点杂质对色谱系统的污染.3个添加水平的回收率为85.6%～120.9%,相对标准偏差在1.2%～17.3%之间.方法干扰小、重现性好、自动化程度高,能够对含脂羊毛中有机氯和有机磷类杀虫剂残留准确地定性定量分析.     

气相色谱-电子轰击离子源质谱法分析卷烟和烟叶中29种农药的残留

开展了卷烟和烟叶中有机氯、有机磷和拟除虫菊酯3类29种农药残留的气相色谱-电子轰击离子源质谱(GC-EI/MS)的分析方法研究。优化与选择了卷烟和烟叶样品的前处理条件,样品经正己烷-丙酮(体积比为1∶1)混合提取剂超声提取、Florisil硅土和中性氧化铝双净化剂固相萃取柱净化、二氯甲烷-正己烷(体积比为95∶5)混合洗脱剂洗脱和浓缩后,以磷酸三苯酯(TPP)为内标物,采用GC-EI/MS的选择离子监测方式(SIM)进行定性和定量分析。当样品的加标水平为20,50,100 μg/kg时,加标回收率为70%～110%,相对标准偏差在2%～8%之间;除了甲氰菊酯、氯菊酯和溴氰菊酯的方法检出限(LOD)分别为1.85,1.74与2.54 μg/kg外,其余的26种农药的LOD均小于0.8 μg/kg;线性范围为5.0～500.0 μg/kg,相关系数都大于等于0.9994。此分析方法已成功地应用于卷烟和烟叶样品中3类29种痕量农药残留的分析