Determination of organochlorine pesticides (OCPs) in breast milk from Rio Grande do Sul,Brazil, using a modified QuEChERS method and gas chromatography-negative chemical ionisation-mass spectrometry

ABSTRACT

The food chain is the main source of exposure to humans by organochlorine pesticides (OCPs) due to the bioaccumulation. Breast milk can accumulate OCPs, so this matrix is often used as an environmental bioindicator. The currently available methods for the determination of several OCPs and metabolites in breast milk involve, in general, multi-step sample preparation and quantification techniques with low selectivity, high cost and much time and labour. Thus, a fast and efficient method based on sample preparation using the quick, easy, cheap, effective, rugged and safe (QuEChERS) method combined with gas chromatography coupled to mass spectrometry with negative chemical ionisation (GC-NCI-MS) was developed, validated and applied for determination of 16 OCPs and metabolites in breast milk samples. The extract was cleaned by dispersive solid-phase extraction (d-SPE) using MgSO₄ and C18, evaporated in a Turbovap® system, redissolved and analysed by GC-NCI-MS. The method was validated showing acceptable recoveries (72–118%) and precision (RSD <19%). Method limits of detection (LODs) and quantification (LOQs) ranged from 0.75 to 7.5 ng g^?1 and from 2.5 to 25 ng g^?1 lipid, respectively. The method was successfully applied to 20 samples of breast milk from different regions of the Rio Grande do Sul state, Brazil, of which 75% contained residues below the LOQs.     

气相色谱/负化学电离源质谱法测定底泥中的有机氯农药

建立了气相色谱/负化学电离源质谱(GC-NCI-MS)法测定底泥中24种有机氯农药(OCPs)残留的方法.样品采用索氏提取、硅胶/氧化铝复合柱分离纯化,p,p'DDT、o,p'-DDT采用外标法定量,其余的有机氯农药均采用内标法定量.同时,对气相色谱/负化学电离源质谱(GC-NCI-MS)法与气相色谱/电子轰击离子源质...     

气相色谱-负化学电离源质谱法测定鱼油中16种多氯联苯

建立了气相色谱-负化学电离源质谱(GC-NCI-MS)同时测定鱼油中16种多氯联苯(PCBs)的方法。鱼油样品经正己烷提取和浓硫酸净化,在选择离子监测模式下进行GC-NCI-MS检测。所检测的PCBs在0.01~10 μg/L范围内呈现良好的线性关系(r>0.99),定量限(S/N=10)在3~67 pg/g之间。基质加标回收率为62.3%~121.8%,相对标准偏差(n=3)≤12%。相比传统的多种填料固相萃取前处理法,本方法样品处理简单快速,有机溶剂使用量少,具有较好的抗基质干扰能力和较高的灵敏度,适用于鱼油中痕量共平面多氯联苯及常见指示性多氯联苯等的同时检测。     

Determination of 41 polybrominated diphenyl ethers in soil using a pressurised solvent extraction and GC-NCI-MS method

A rapid and reliable analytical method based on pressurised solvent extraction (PSE) and GC-NCI-MS was developed for the determination of 41 different PBDEs in soil. All PBDEs, including mono- to hepta-BDEs (sum of 39 congeners), one nona-BDE and deca-BDE, were efficiently extracted from soil samples using the extraction technology of PSE. The extract was then cleaned up on a florisil column. Satisfactory separation of 41 PBDE congeners was obtained on a 15-m DB-5MS capillary column, saving the use of another 30-m column specific for the separation of mono- to hepta-BDEs. PBDEs were identified and quantified by GC-MS in negative chemical ionisation (NCI) mode, and further confirmed in semi electron impact (SEI) mode when the ion source was also NCI. The method detection limits ranged from 0.01 to 0.03?ng?g^?1?dw for mono- to hepta-BDEs, 1.43?ng?g^?1?dw for the nona-BDE and 0.20?ng?g^?1?dw for deca-BDE. The applicability of the method was tested in soil samples collected from an e-waste recycling site at Guiyu. Twenty-one PBDEs (mono- to deca-) were detected, and eighteen congeners were quantified. The concentration range of PBDEs was 0.78–436?ng?g^?1?dw. BDE-47, BDE-99, BDE-153, BDE-183, BDE-206 and BDE-209 were the dominant congeners, and BDE-209 accounted for 62% of the total PBDEs. The congener profiles of PBDEs in soil samples were similar to those in three commercial PBDE products (Penta-, Octa- and Deca-BDE), and Deca-BDE product was the most important contributor.     

厦门近海沉积物中PBDEs与PBBs残留的GC-NCI/MS和GC-ECD分析

将气相色谱-负离子化学源.质谱法(GV-NcI/Ms)和气相色谱-电子捕获检测法(GC-ECD)应用于分析沉积物中6种多溴联苯醚(PBDE8)和5种多溴联苯(PBBs)残留.沉积物样品以V(正己烷):V(丙酮)=1:1作为提取剂,采用索式提取法,提取液经酸性硅胶和中性硅胶层析柱净化和正己烷洗脱后.以PCB-103为内标物和GC-NCI-MS的选择离子监测方式(SIM)进行定性与定量分析,PBDE-209则采用GC-ECD法分析.平均加标回收率为93.3%～110.8%,相对标准偏差为1.2%～8.6%,方法检测限均小于0.20 μg/kg(PBDE-209的方法检测限是7.74 μg/kg),相关系数都大于0.9990.所分析沉积物样品中均含有微量的PBDE-99、PBB-49和PBDE-209.     

固相萃取-气相色谱-负化学离子源质谱法测定运动场所合成材料面层和稀释剂中的短链氯化石蜡

建立了用于运动场所合成材料面层和稀释剂中短链氯化石蜡（SCCPs）总含量测定的固相萃取-气相色谱-负化学离子源质谱法（SPE-GC-NCI-MS）。对气相色谱和质谱的分析条件进行了优化;试样经超声提取、弗罗里硅土固相萃取小柱净化后,选择性离子监测模式（SIM）扫描,外标法定量。方法在0.0501~100.17 mg/L的宽广范围内有良好的线性关系,线性相关系数R²为0.9995,方法检出限低至0.50 μg/g（即0.000050%）,平均回收率为83.2%~96.3%,相对标准偏差为1.56%~6.02%。对10批次实际样品进行检测,含量在0.016%~0.55%范围内,检测结果满足欧盟对此类物质的限量要求。方法可用于运动场所合成材料面层和稀释剂中短链氯化石蜡的实际检测。     

Development of a Solid-Phase Extraction Method Based on Biocompatible Starch Polyurethane Polymers for GC-MS Analysis of Polybrominated Diphenyl Ethers in Ambient Water Samples

A new solid-phase extraction (SPE) method for the extraction, enrichment, and analysis of eight polybrominated diphenyl ethers (PBDEs) in water was developed. The current approach involves using a cross-linked starch-based polymer as an extraction adsorbent and determining the PBDE analytes of interest using gas chromatography-mass spectrometry in negative chemical ionization mode (GC-NCI-MS). The starch-based polymer was synthesized by the reaction of soluble starch with 4,4′-methylene-bis-phenyldiisocyanate as a cross-linking agent in dry dimethylformamide. Various parameters impacting extraction efficiencies, such as adsorbent quantity, sample volumes, elution solvents and volumes, and methanol content, were carefully optimized. The 500 mg of starch-based polymer as an adsorbent used to extract 1000 mL of spiked water, presented high extraction recoveries of eight PBDEs. The linearity of the extraction process was investigated in the range of 1–200 ng L⁻¹ for BDE-28, 47, 99, 100, and 5–200 ng L⁻¹ for BDE-153, 154, 183, and 209, with coefficients of determination (r2) exceeding 0.990 for all PBDEs. The limits of detection (LODs) ranged from 0.06 to 1.42 ng L⁻¹ (S/N = 3) and the relative standard deviation values (RSD) were between 3.6 and 9.5 percent (n = 5) under optimum conditions. The method was successfully used to analyze river and lake water samples, where it exhibited acceptable recovery values of 71.3 to 104.2%. Considering the excellent analytical performance and comparative cost advantage, we recommend the developed starch-based SPE method for routine extraction and analysis of PBDEs in water media.     

超声辅助萃取气相色谱-质谱法测定松针中的多溴联苯醚

建立了测定松针样品中多溴联苯醚(PBDEs)的分析方法。松针样品经过正己烷-丙酮(体积比为1∶1)混合溶液超声萃取、浓硫酸和氧化铝柱净化后,采用气相色谱-负化学电离源质谱(GC-NCI-MS)选择离子监测(SIM)模式检测,内标法定量。结果表明,方法的加标回收率为83.8%~107.5%,三溴~七溴代联苯醚的仪器检出限为0.152~ 0.770 pg,十溴代联苯醚(BDE-209)的检出限为11.1 pg;三溴~七溴代联苯醚的方法检出限(湿重)为3~15 pg/g,BDE-209的方法检出限(湿重)为222 pg/g。方法具有良好的重现性、较高的灵敏度和良好的回收率。实际样品分析表明,松针中BDE-209是主要的同类物,约占8种PBDEs总量的82.3%,低溴代联苯醚以2,2′,4,4′-四溴联苯醚(BDE-47)为主。     

气相色谱-负化学电离源质谱法测定土壤中的多溴联苯醚

本文建立了气相色谱-负化学电离源质谱(GC-NCI-MS)法分析环境土壤及底泥样品中多溴联苯醚(PBDEs)的方法。样品采用索氏提取、多层硅胶柱分离纯化、内标法(BDE28、47、99、100、153、154、183)及同位素稀释法(BDE209)定量。上述定量的8种BDE同族体的方法回收率在96.7%～138.5%之间,相对标准偏差(RSD)为9.1%～22.3%(n=4)。应用该方法分析环境土壤及底泥样品的结果表明,8种所监测的PBDEs均被检出,土壤中PBDE浓度的总和为1437.6ng/g干重,底泥中为241.4ng/g干重,土壤和底泥中BDE209分别占PBDE浓度的总和的98.4%和92.7%。     

气相色谱-负离子化学电离质谱法分析测定蔬菜水果中有机磷农药的残留

将气相色谱-负离子化学电离质谱法(GC-NCI-MS)应用于蔬菜水果中9种有机磷农药残留的分析测定,初步解析了这些农药的NCI-MS特征阴离子结构和断裂机理,并初步探讨了GC-NCI-MS分析蔬菜水果中有机磷农药残留时基体效应的影响。采用空白样品基体匹配校准曲线法(MC)进行定量分析,有效地降低了基体效应的影响。蔬菜水果样品用乙酸乙酯超声提取,以乙硫磷为内标物,采用GC-NCI-MS的选择离子监测方式(SIM)进行定性和定量分析。9种有机磷农药的方法检测限为0.12～1.0 μg/kg。在方法的检测限与1000 μg/kg范围内,线性相关系数都大于0.9993。当空白蔬菜水果(西红柿）样品的加标水平为100,400,800 μg/kg时,平均加标回收率为78%～126%,相对标准偏差为0.58%～14.7%。