Simultaneous determination of 18 pyrethroids in indoor air by gas chromatography/mass spectrometry

An analytical method was developed for the simultaneous measurement of 18 pyrethroids (allethrin, bifenthrin, cyfluthrin, cypermethrin, cyphenothrin, deltamethrin, empenthrin, fenpropathrin, furamethrin, imiprothrin, metofluthrin, permethrin, phenothrin, prallethrin, profluthrin, resmethrin, tetramethrin and transfluthrin) in indoor air. The pyrethroids were collected for 24 h using a combination of adsorbents (quartz fiber filter disk and Empore C18 disk), with protection from light, and then extracted with acetone, concentrated, and analyzed by GC/MS. They could be determined accurately and precisely (detection limits: ca. 1 ng/m³). The collected pyrethroid samples could be stored for up to one month at 4 °C in a refrigerator.     

分散固相萃取-在线凝胶色谱-气相色谱-质谱联用法快速检测紫菜中的农药多残留

建立了紫菜中农药多残留的在线凝胶色谱-气相色谱-质谱联用（GPC-GC/MS）检测方法。以有机氯、有机磷、三嗪类和菊酯类的19种农药为目标物,对比了丙酮、丙酮/二氯甲烷（1:1,v/v）和乙腈3种有机溶剂的提取效果,通过石墨化炭黑粉（GCB）和N-丙基乙二胺粉（PSA）分散固相萃取净化和GPC在线净化,气相色谱-质谱联用法分析,外标法定量。结果表明,此方法实现了在线净化与分析检测的自动化,缩短了分析时间。分析物在10~1000 μg/L范围内线性关系良好,相关系数r>0.995;采取GPC大体积进样和气相色谱进样口的程序升温方式提高了检测灵敏度,检出限为0.005~0.03 mg/kg。方法的平均添加回收率在70%~120%之间,相对标准偏差（RSD）均小于15%。该方法简单、快速、具有良好的回收率和重复性,适用于紫菜样品中农药多残留的快速灵敏检测。     

羰基铁粉掺杂整体柱萃取-在线热解吸进样气相色谱-串联质谱法分析茶叶样品中拟除虫菊酯类农药残留

制备了羰基铁粉掺杂硅胶整体柱，用于拟除虫菊酯类农药残留萃取，并与气相色谱-串联质谱（GC-MS/MS）法联用，建立了在线富集、热解吸GC-MS/MS测定茶叶样品中拟除虫菊酯类农药残留方法。研究将端羟基聚二甲基硅氧烷共价键合到SiO₂网络表面，并同时键合羰基铁粉。将目标分析物吸附并浓缩在聚二甲基硅氧烷位点上后，利用羰基铁粉的高频感应加热特性成功实现了GC-MS/MS直接气体进样并可达到快速、均匀解吸的目的。实验结果表明，在最佳条件下，本方法的富集倍数可达到约1000倍。拟除虫菊酯类农药残留的检出限为3.8~7.5 μg/kg，相对标准偏差为3.2%~6.8%（n=6）。该方法的提取回收率为97.7%~110.5%，相关系数≥0.9960。该法的吸附容量大，在电磁感应的条件下进行热脱附继而直接与GC-MS结合实现在线分析以及无溶剂洗脱。与常规固相微萃取（SPME）方法相比，该方法具有富集因子高、整体柱吸附容量大、可重复使用、自动化程度高、普适性好等优点。在样品前处理及复杂基质中农药残留的提取方面具有重要的研究意义。     

Pesticide residue determination in vegetables from western China applying gas chromatography with mass spectrometry

In this study,an effort has been made to evaluate the pesticide residues in vegetables from western China. Fifty‐one pesticides, including organophosphorus, organochlorine, carbamate and pyrethroid, were detected in 369 commonly used vegetables by GC‐MS. Concentrations of organophosphorus pesticides were detected ranging from 0.0008 to 18.8200 mg/kg, among which organophosphorus pesticide concentrations exceeded their maximum residue levels (MRLs) in five samples. Carbamate and organochlorine pesticides were determined to have concentrations in the range of 0.0012–0.7928 mg/kg. The residual concentrations of carbamate pesticides in six samples and organochlorine pesticides in four samples exceeded their MRLs. The residual concentrations of five pyrethroid pesticides were within the range of 0.0016–6.0827 mg/kg and the pyrethroid residues in two samples exceeded their MRLs. The results revealed that pesticide residues in 70.73% of the vegetables samples were not detected, while in the rest of vegetables there were one or more pesticide residues and some even exceeded their MRLs, which would threaten the health of consumers. Our work provides significant information for the food safety regulations to control the excessive use of some pesticides on those kinds of vegetables from western China. Copyright © 2016 John Wiley & Sons, Ltd.     

Measurements of radon,thoron and their progeny in Gifu prefecture,Japan

Summary Due to the rocky neighborhood, consisting of mostly granite with high radium content, an elevated radon concentration was found in a territory of Gifu prefecture situated in the middle of Japan. Radon concentrations in water were measured and were found to be considerably high. Since indoor radon and radon progeny concentrations might be relatively high, their concentrations were also analyzed. Besides the radon and radon progeny, thoron and thoron progeny concentrations were also investigated. Dose estimations for radon and thoron in indoor air are discussed.     

A survey of 222Rn concentrations in dwellings of Turkey

As part of a national program to determine public exposure to natural radiation, indoor air ²²²Rn concentrations were determined in dwellings of Turkey. The ²²²Rn concentrations were measured with time-integrating passive nuclear etched track detectors in 27 provincial centers. The indoor radon concentrations were found to be in the range of 10-380 Bq^.m^-3. This revised version was published online in August 2006 with corrections to the Cover Date.     

Determination of Pyrethroid and Organophosphorus Insecticides in Indoor Air by Microwave-Assisted Extraction with Gas Chromatography/Mass Spectrometry

The goal of this study was to evaluate the efficiency of microwave-assisted extraction for the recovery of pyrethroid and organophosphorus insecticides adsorbed on quartz fiber filters and C18 disks used for indoor air sampling. The extraction solvent, temperature, and time were optimized by spiking tests. The recoveries for the insecticides obtained by microwave-assisted extraction with acetone at 50°C for 5 min were between 71.9% and 119.2% with relative standard deviations between 0.3% and 9.3% at two spike levels (0.1 µg and 1.0 µg). The results of the microwave-assisted extraction under the validation conditions were comparable to those obtained by Soxhlet extraction, which was used as a reference technique. In a preliminary analysis, resmethrin and tetramethrin were determined in the indoor air of an apartment unit at concentrations of 7.8 ng/m³ and 66.0 ng/m³, respectively, using the microwave-assisted extraction-based method with gas chromatography/mass spectrometry.     

快速滤过型净化结合气相色谱-串联质谱法同时检测茶叶中10种拟除虫菊酯农药残留

建立了快速滤过型净化（m-PFC）结合气相色谱-串联质谱（GC-MS/MS）测定茶叶中10种拟除虫菊酯类农药残留的方法。比较了采用不同提取溶剂（乙腈、丙酮和乙酸乙酯）和不同提取方式（不加水浸泡和加水浸泡）时10种农药的提取效率；比较了2种QuEChERS净化管和m-PFC柱对茶叶提取液的净化效果和农药残留的回收率。结果表明，茶叶样品不加水浸泡，用乙腈提取效果最好；m-PFC柱对茶叶提取液净化效果良好，而且能保证较高的农药回收率。10种拟除虫菊酯农药在相应的范围内有良好的线性关系，相关系数（R²）大于0.9980；10种农药在4个水平添加下的回收率为87.5%~111.3%，RSD为2.1%~8.9%。方法的检出限为0.001~0.015 mg/kg，定量限为0.003~0.05 mg/kg。利用该方法检测市售50例茶叶样品中10种拟除虫菊酯农药的残留，检出率为48%，但农药残留量均在国家标准限量值以下。与传统QuEChERS法和固相萃取法相比，该方法具有操作简单、准确度和精密度良好等优点，为多种拟除虫菊酯类农药在茶叶中的残留测定提供了快速检测的新方法。     

Multiresidue method using SPME for the determination of various pesticides with different volatility in confined atmospheres

An analytical method is described for assessing the vapour concentration of 11 pesticides (bioallethrin, chlorpyriphos methyl, folpet, malathion, procymidone, quintozene, chlorothalonil, fonofos, penconazole and trimethacarb) in confined atmospheres (e.g. a greenhouse after pesticide application). This study is a successful extension of a method previously developed by the authors for dichlorvos to much less volatile pesticides. Sampling was performed by using polydimethylsiloxane–solid phase micro-extraction (PDMS–SPME) fibres immersed in a 250-mL sampling flask through which air samples were dynamically pumped from the analysed atmosphere. After a 40-min sampling duration, samples were analysed by GC/MS.Calibration was performed from a vapour-saturated air sample. The linearity of the observed signal versus pesticide concentration in the vapour phase was proved from spiked liquid samples whose headspace concentrations were measured by using the proposed method. This procedure gave calibration curves with regression coefficients (R²) greater than 0.98, and the repeatability of these measurements was found with RSDs of 1.9–7.6%. As a field application test, this analysis procedure was used for the determination of gaseous procymidone concentrations as a function of time in the atmosphere of an experimental 8-m² and 20-m³ greenhouse. The pesticide was sprayed according to real cultivation conditions, and measurements were made for 80 h after application (8 measurements). The observed concentrations found ranged from 200 to 500 µg m^–3, thus indicating the level of contamination of the air breathed by people in such working conditions.Abbreviations GC/MS gas chromatography/mass spectrometry - SIM selective ion monitoring - FC43 perfluorotributylamine - RSD relative standard deviation - LOD limit of detection - LOQ limit of quantification     

气相色谱法测定坚果中8种拟除虫菊酯农药残留

建立了东盟进口坚果夏威夷果、开心果、杏仁中8种拟除虫菊酯农药残留的检测方法。样品采用乙腈作萃取溶剂超声波提取,经中性氧化铝串联弗罗里硅土小柱净化,组分经不同极性的两根毛细管柱进行分离,采用气相色谱法以ECD检测器检测坚果中8种拟除虫菊酯农药。该方法在0.01~1.0μg/m L浓度范围内具有良好的线性关系,相关系数为0.999 2~0.999 9;在农药添加浓度为10,20,50μg/kg时,回收率为71%~115%,相对标准偏差为4.5%~9.8%,检出限(LOD,S/N=3)为0.014~0.28μg/kg,定量下限(LOQ,S/N=10)为0.047~0.94μg/kg。该方法分离效果好,准确可靠,回收率高,方便快速,可用于坚果中农药残留的日常检测。     

大体积进样气质联用法测定浓缩果蔬汁中农药的残留量

建立了气相色谱-质谱同时检测果蔬汁中多类农药残留的方法。利用Agilent仪器的保留时间锁定功能（RTL）及相应的质谱农药库，建立了多类农药选择离子监测的分组时间窗，避免了仪器维护后农药保留时间烦琐的更新过程，保证了农药保留时间的重复性；探讨了具有溶剂排空模式的程序升温蒸发（PTV）对大体积进样的作用。通过对分流排空量、吹扫时间、PTV温度及其进样体积等PTV参数的优化，提高了检测灵敏度。通过同位素标汜农药作为内标，GC—MS的定量可靠性得到改善。     

Determination of pesticides in seaweeds by pressurized liquid extraction and programmed temperature vaporization-based large volume injection–gas chromatography–tandem mass spectrometry

A rapid method for the simultaneous identification and quantification of pesticide residues in edible seaweed has been developed. Target analytes were three pyrethroid, a carbamate and two organophosphorus pesticides. The procedure consists of a pressurized liquid extraction (PLE) with integrated clean-up, followed by gas chromatography coupled to tandem mass spectrometry. Five PLE parameters were investigated using a screening design: temperature, static extraction time, number of cycles, percent of flush volume and quantitative composition of the n-hexane/ethyl acetate extraction solvent. The effect of the in-cell clean-up with Florisil^® and graphitized carbon black adsorbents was investigated using a Doehlert response surface design. Large volumes of sample extracts were injected using a programmed-temperature vaporizer (PTV-LVI) to improve both sensitivity and selectivity of measurements. Quantification was carried by the internal standard method with surrogate deuterated standards. The method showed excellent linearity (R² > 0.999) and precision (relative standard deviation, RSD ≤ 8%) for all compounds, with detection limits ranging from 0.3 pg g⁻¹ for chlorpyrifos-ethyl, to 3.0 pg g⁻¹ for carbaryl (23.1 pg g⁻¹ for deltamethrin). Recoveries in real seaweed samples were within the range 82–108%. The method was satisfactory validated for the analysis of wild and cultivated edible seaweeds. The presence of pyrethroid and organophosphorus pesticides in some of the samples was evidenced.     

Radon dose estimates assisted by continuous measurements

Continuous measurements of concentrations of radon and radon decay products, and equilibrium factor were carried out in the indoor air of 12 schools at the beginning of 2000. Average values of the parameters measured, obtained during working time only and during the whole period, were compared and applied to calculate exposure of a person breathing in this air. Results of short-term continuous measurements are proposed to be used to correct the exposure, generally based on the radon concentration obtained by etched track detectors, and the justification of applying this procedure is discussed.     

气相色谱-负化学源质谱法测定蔬菜中17种拟除虫菊酯类农药残留量

建立了气相色谱-负化学源质谱检测蔬菜中17种拟除虫菊酯类农药残留量的方法。样品中的目标物经乙腈提取后,用乙二胺-N-丙基甲硅烷(PSA)和石墨化炭黑填料进行分散固相萃取净化,气相色谱-负化学源质谱选择离子监测模式测定,同位素内标法定量。在甜豌豆、绿花菜和大葱基质中均未见干扰所有农药测定的现象。17种拟除虫菊酯类农药的定量限均为0.02～5 μg/kg。在10、20、30和100 μg/kg等4个添加水平下,所有农药的回收率均为71.0%～139.0%,相对标准偏差≤12.8%。该方法可作为蔬菜中17种菊酯类农残检测的确证方法。     

Evaluation of tungsten coil electrothermal vaporization-Ar/H2 flame atomic fluorescence spectrometry for determination of eight traditional hydride-forming elements and cadmium without chemical vapor generation

A tungsten coil electrothermal vaporizer (W-coil ETV) was coupled to an Ar/H(2) flame atomic fluorescence spectrometer for the determination of eight traditional hydride-forming elements (i.e., As, Bi, Ge, Pb, Sb, Se, Sn, and Te) as well as cadmium without chemical vapor generation. A small sample volume, typically 20muL, was manually pipetted onto the W-coil and followed by a fixed electric heating program. During the vaporization step, analyte was vaporized off the coil surface and swept into the quartz tube atomizer of AFS for further atomization and excitation of atomic fluorescence by a flow of Ar/H(2) gas, which was ignited to produce the Ar/H(2) flame. The tungsten coil electrothermal vaporizer and Ar/H(2) flame formed a tandem atomizer to produce reliable atomic fluorescence signals. Under the optimal instrumental conditions, limits of detection (LODs) were found to be better than those by flame atomic absorption spectrometry (FAAS) or inductively coupled plasma optical emission spectrometry (ICP-OES) for all the nine elements investigated. The absolute LODs are better or equivalent to those by hydride generation atomic fluorescence spectrometry (HG-AFS). Possible scattering interferences were studied and preliminary application of the proposed method was also reported.     

Gas chromatographic and mass spectrometric studies on pyrethroid photo- and biotransformation

Summary Applications of high resolution gas chromatography (GC) and mass spectrometry (MS) in pesticide chemistry are demonstrated by pyrethroid photo- and biotransformation studies. Degradation of chrysanthemate pyrethroids (e.g. the natural pyrethrins, allethrin, tetramethrin and cyphenothrin) used as indoor insecticides is investigated by GC-MS using negative chemical ionization (NCI). Ozonolysis results in the formation of carbox-aldehydes as major indoor transformation products. In vitro metabolism of (S)-bioallethrin and the natural pyrethrins by NADPH dependent oxidases is studied using GC-MS with positive chemical ionization (PCI). Interpretation of the PCI mass spectra yields molecular weight and structural information about the metabolites and their derivatives. The photochemistry of novel non-ester pyrethroids with ether or alkane central linkages such as ethofenprox is investigated by electron impact (EI) GC-MS.     

Simultaneous liquid chromatographic determination of 39 polycyclic aromatic hydrocarbons in indoor and outdoor air and application to a survey on indoor air pollution in Fuji, Japan

An analytical method was established for the simultaneous determination of 39 polycyclic aromatic hydrocarbons (PAHs) in air. The method was applied to a survey of gaseous and particulate PAHs in household indoor air. The survey was performed in 21 houses in the summer of 1999 and in 20 houses in the winter of 1999-2000 in Fuji, Japan. Thirty-eight PAHs were determined in indoor and outdoor air in the summer, and 39 PAHs were determined in indoor and outdoor air in the winter. The concentrations of gaseous PAHs in indoor air tended to be higher than those in outdoor air in the summer and winter. The concentrations of particulate PAHs in indoor air were the same as or lower than those in outdoor air in the summer and winter. PAH profiles, correlations between PAH concentrations, and multiple regression analysis were used to determine the factors affecting the indoor PAH concentrations. These results showed that gaseous PAHs in indoor air were primarily from indoor emission sources, especially during the summer, and that indoor particulate PAH concentrations were significantly influenced by outdoor air pollution.     

Assessing indoor air exposures using passive sampling with bioanalytical methods for estrogenicity and aryl hydrocarbon receptor activity

Passive air sampling was undertaken using polyurethane foam passive air samplers at three types of locations, including indoors (six offices) at buildings in the central business district (CBD) and at a private suburban home (indoor and outdoor) located 9 km from the CBD in Brisbane, Queensland, Australia. Estrogenic (E-SCREEN—MCF7-BOS) and aryl hydrocarbon receptor (AhR) (CAFLUX—H4G1.1c2) activity were assessed for samples collected from each of these locations. The samples were tested either as crude extracts (“untreated”) or were subjected to H₂SO₄ silica gel (“treated”) for each location in order to determine whether chemicals, which are not resistant to this treatment like polycyclic aromatic hydrocarbons, potentially account for the observed activity. In most cases, H₂SO₄ treatment resulted in a statistically significant reduction of potency for both endpoints, suggesting that chemicals less resistant to treatment may be responsible for much of the detected biological activity in these locations. Estrogenic potency measurements (<0.22–185 pg m⁻³) were highest in the indoor offices, followed by the indoor suburban home and finally the outdoor suburban home (which was not estrogenic). Total AhR activity for crude extracts (1.3–10 pg m⁻³) however was highest for the outdoor suburban home site. Levels of polycyclic aromatic hydrocarbons were monitored indoors and outdoors at the suburban home. At that location, polycyclic aromatic hydrocarbon air concentrations were on average approximately two times higher outdoor than indoor, while AhR potency was five times higher outdoor than indoor. No significant correlation was found between the estrogenic and AhR activity (P = 0.88) for the sites in this study. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

超声波提取-固相萃取净化-气相色谱法分析烟草中拟除虫菊酯类农药及氟节胺残留

建立了超声波提取-固相萃取净化-气相色谱联用测定烟草中多种拟除虫菊酯类农药及氟节胺残留量的方法。与现行标准方法相比,本方法前处理简单、快速、有机溶剂消耗量少,且增加了分析目标物的数量。8种拟除虫菊酯类农药及氟节胺在0.1、0.5和1μg/g三个加标水平的回收率为86%～111%,相对标准偏差为0.2%～4.1%,满足当前烟草农药残留的检测要求。     

Determination of organophosphate esters in air samples by dynamic sonication-assisted solvent extraction coupled on-line with large-volume injection gas chromatography utilizing a programmed-temperature vaporizer

An on-line method for the determination of airborne organophosphate esters based on dynamic sonication-assisted solvent extraction and large-volume injection (LVI) gas chromatography with nitrogen-phosphorous detection is introduced. The LVI is performed with a programmed-temperature vaporizer. The entire extracted fraction of 800 microl (hexane-methyl-tert.-butyl ether, 7:3, v/v) is introduced directly into the GC system without any clean-up step following extraction. The extraction and analysis step were completed in less than 15 min. The limit of detection of the investigated organophosphate esters was established to be in the range of 5-32 pg/filter. The correlation coefficients (r2) were investigated in the linear range study of the entire system and established to be approximately 0.9900 for all the investigated organophosphates esters. Applications of the method was demonstrated with the extraction of air samples collected onto glass fiber filters from different indoor environments. Six organophosphate esters were found at the levels 0.4-138 ng/m3.