A Microwave‐assisted Headspace Solid‐phase Microextraction for Rapid Determination of Synthetic Polycyclic and Nitro‐aromatic Musks in Fish Samples

Rapid solvent‐free microwave‐assisted headspace solid‐phase microextraction (MA‐HS‐SPME) coupled with gas chromatography‐mass spectrometry (GC‐MS) was developed to determine synthetic polycyclic and nitro‐aromatic musks in fish samples. Four commonly used synthetic musks, galaxolide (HHCB), tonalide (AHTN), musk xylene (MX) and musk ketone (MK) were employed in the method development and validation. The parameters (microwave irradiation time, irradiation power, amount of water addition, pH value and addition of NaCl) affecting the extraction efficiency of analytes from fish slurry were systematically investigated and optimized. The best extraction conditions were achieved when the fish sample 2‐g mixed with 4‐mL methanol and 15‐mL deionized water (containing 4 g of NaCl, pH 2.0 in a 40‐mL sample‐vial) was microwave irradiated at 80 watt for 5 min. The limits of quantification (LOQ) were 0.4 to 1.2 ng/g in 2‐g of wet tissue. The precision for these analytes, as indicated by relative standard deviations, were less than 9% for both intra‐ and inter‐day analysis. Accuracy, expressed as the mean extraction recovery, was between 80 to 92%. A standard addition method was used to quantitate these four synthetic musks, and the total concentrations ranged from 2.1 to 23.1 ng/g in various fish samples.     

Trace Determination of Rhodamine B and Rhodamine 6G Dyes in Aqueous Samples by Solid‐phase Extraction and High‐performance Liquid Chromatography Coupled with Fluorescence Detection

A simple and reliable method was developed to detect two basic synthetic dyes, rhodamine B (RB) and rhodamine 6G (R6G), in wastewater and surface water samples by high performance liquid chromatography with fluorescence detection (HPLC‐FLD). These dyes have been reported to be both mutagenic and carcinogenic in various organisms. The contents of these two dyes in water samples were extracted by Oasis HLB solid‐phase extraction (HLB‐SPE), and were then determined by an isocratic HPLC using an Atlantis® T3‐C18 column. Water samples at various pH conditions and the compositions of eluents for SPE were evaluated. The results indicate that the proposed method is precise and sensitive in analyzing these two basic synthetic dyes, and the limits of quantitation were 1.5 ng/L for RB and 0.3 ng/L for R6G in 100 mL of water samples. The recovery of analytes in spiked surface water and municipal wastewater treatment plant (WWTP) effluent samples ranged from 61 to 90% with the precision (RSD) ranging from 2 to 12%. The concentrations of analytes were detected in various water samples ranging from 0.7 to 81 ng/L.     

Solid‐phase Extraction Coupled Simple On‐line Derivatization Gas Chromatography – Tandem Mass Spectrometry for the Determination of Benzophenone‐type UV Filters in Aqueous Samples

The rapid determination of three benzophenone‐type UV filters: 2‐hydroxy‐4‐methoxy‐benzophenone (BP‐3), 2,4‐dihydroxybenzophenone (BP‐1) and 2,2′‐dihydroxy‐4‐methoxy‐benzophenone (BP‐8), in aqueous samples is described. The method involved the extraction of an aqueous sample using an Oasis HLB solid‐phase extraction (SPE) cartridge, followed by on‐line derivatization gas chromatography ‐ tandem mass spectrometry (GC‐MS/MS) with a trimethylsilylating (TMS) reagent. This eco‐friendly, injection‐port derivatization method, is sensitive, rapid, and provides reproducible results for these hydroxylated benzophenones in aqueous samples. The limits of quantitation (LOQs) were determined to be 1.0 to 2.5 ng/L for samples in 100 mL of water. The precision for these analytes, as indicated by relative standard deviations (RSDs), proved to be less than 11% for both intra‐ and inter‐day analysis. Accuracy, expressed as the mean extraction yield, was between 80 and 106%. The method was then applied to some environmental water samples, river water and samples of effluents from a wastewater treatment plant (WWTP), having the potential to contain BP‐3 and BP‐1.     

超声提取/固相萃取测定固体介质中合成麝香及有机磷酸酯阻燃剂/增塑剂

基于超声提取与固相萃取技术,建立了沉积物和污泥中合成麝香与有机磷酸酯增塑剂/阻燃剂联合前处理方法,并采用气相色谱-质谱对目标化合物进行定性定量分析。考察了不同溶剂对目标化合物萃取效率的影响,确定以丙酮与乙腈-水(1∶3)的组合作为超声萃取溶剂。研究了基质效应和老化效应对目标化合物回收率的影响。结果表明,不同加标浓度下,4种常见合成麝香和9种常用有机磷酸酯的回收率为(27%±12%)~(117%±9%)。     

气相色谱-串联质谱法同时快速检测环境水样中11种合成麝香

应用气相色谱-串联质谱法(GC-MS/MS)建立了环境水样中佳乐、吐纳、特拉斯、开许梅龙、萨利、粉檀、二甲苯、麝香酮、伞花、葵子、西藏11种典型的合成麝香(Synthetic Musks)的同时快速检测方法。采用Oasis HLB固相萃取柱、乙酸乙酯为洗脱液对水样进行预处理。在最优条件下,目标物线性范围均为0.05~10ng/L(R2为0.995~0.999),回收率为83.9%~112.7%,相对标准偏差(RSD)为3.5%~9.9%。该方法具有检测限低、回收率高等优点,经实际样品测试,可适用于环境水样中上述11种典型合成麝香的同时检测。     

分散微固相萃取-超高效液相色谱-高分辨质谱法测定果汁饮料中的吗啉残留

基于强阳离子交换填料(PCX),采用分散微固相萃取(DMSPE)前处理技术,结合超高效液相色谱-四级杆-静电场轨道阱高分辨质谱联用技术(UPLC/Q Orbitrap),建立了果汁饮料中吗啉残留的快速检测分析方法.通过对DMSPE技术中PCX用量、吸附时间、洗脱溶剂氨水浓度和洗脱体积的优化,实现样品中吗啉的最优提取.以BEH HILIC色谱柱(100 mm×2.1 mm,1.7 μm)进行色谱分离,通过静电场轨道阱质谱tMSMS采集模式获得吗啉的精确母离子及碎片离子质量数,进行定性定量分析.结果显示,吗啉在l～ 100 μg/L浓度范围内存在良好的线性关系(R2＞0.999),方法检出限和定量限分别为1和2μg/L;平均加标回收率为85.9％ ～ 103.8％,日内和日间精密度分别为3.7％～5.2％和3.5％ ～9.4％.本方法简单精确,灵敏度高,样品处理快捷简便,适用于果汁饮料中吗啉残留的快速分析测定.     

Dispersive micro‐solid‐phase extraction of benzoylurea insecticides in honey samples with a β‐cyclodextrin‐modified attapulgite composite as sorbent

A β‐cyclodextrin‐modified attapulgite composite was prepared and used as a dispersive micro‐solid‐phase extraction sorbent for the determination of benzoylurea insecticides in honey samples. Parameters that may influence the extraction efficiency, such as the type and volume of the eluent, the amount of the sorbent, the extraction time and the ionic strength were investigated and optimized using batch and column procedures. Under optimized conditions, good linearity was obtained for all of the tested compounds, with R² values of at least 0.9834. The limits of detection were determined in the range of 0.2–1.0 μg/L. The recoveries of the four benzoylurea insecticides in vitex honey and acacia honey increased from 15.2 to 81.4% and from 14.2 to 82.0%, respectively. Although the β‐cyclodextrin‐modified attapulgite composite did not show a brilliant adsorption capacity for the selected benzoylurea insecticides, it exhibited a higher adsorption capacity toward relatively hydrophobic compounds, such as chlorfluazuron and hexaflumuron (recoveries in vitex honey samples ranged from 70.0 to 81.4% with a precision of 1.0–3.7%). It seemed that the logP_ow of the benzoylurea insecticides is related to their recoveries. The results confirmed the possibility of using cyclodextrin‐modified palygorskite in the determination of relatively hydrophobic trace pharmaceutical residues.     

Trace Determination of Benzalkonium Chlorides in River and Wastewater by Capillary Electrophoresis following Solid‐Phase Extraction Coupled with Salting‐Out Extraction

Trace levels analysisbenzalkonium chlorides (BAKs) in river water and wastewater treatment plants (WWTP) effluents were determined by capillary electrophoresis (CE) following solid‐phase extraction (SPE) and salting‐out extraction. Salting‐out extraction using an appropriate ratio of sodium chloride (NaCl) and acetonitrile (ACN) mixed with concentrated SPE elutant was capable of providing more than 500‐fold enhancement in detection sensitivity. The ratios of ACN and NaCl for salting‐out extraction were investigated and optimized. Matrix interference was eliminated by salting‐out extraction. Limits of quantitation of BAK homologues were achieved at 0.1 μg/L in 250 mL water samples. Recoveries of BAKs in various spiked water samples ranged from 70% to 84% with relative standard deviation (RSD) less than 9%. Trace amounts of total BAKs were detected in river water and WWTP effluent samples ranging from 27 to 145 μg/L at the first time by CE.     

分散固相萃取-超声辅助分散液液微萃取/高效液相色谱法测定土壤中溴氰菊酯残留

建立了以分散固相萃取-超声辅助分散液液微萃取为样品前处理技术,结合高效液相色谱法(HPLC)测定土壤中溴氰菊酯。样品用甲醇∶水(1∶4,V/V)提取,经布氏漏斗减压抽滤,滤液经N-丙基乙二胺(PSA)、C18、石墨炭黑粉(GCB)净化后,用氯仿萃取,超声,离心后沉积相进行HPLC测定。对分散固相萃取吸附剂的选择及影响分散液液微萃取的因素进行了优化,在最优条件下,溴氰菊酯的富集倍数达到565倍,线性范围为0.005~2.5mg/kg,线性相关系数为0.9998,检出限为0.001mg/kg,平均加标回收率为70.3%~94.5%,相对标准偏差为2.5%~4.7%。该方法具有简便快速、准确灵敏、萃取效率高等特点,可用于土壤中溴氰菊酯残留检测。     

Determination of Trace Methyl Tert‐Butyl Ether in Water Samples Using Dispersive Liquid‐Liquid Microextraction Coupled with GC‐FID

A rapid and sensitive analytical method has been developed for trace analysis of methyl tert‐butyl ether (MTBE) in water samples using dispersive liquid‐liquid microextraction and gas chromatography with flame ionization detection. Factors relevant to the microextraction efficiency, such as the kind of extraction solvent, the disperser solvent and their volumes, the effect of salt, sample solution temperature and the extraction time were investigated and optimized. Under the optimal conditions the linear dynamic range of MTBE was from 0.2 to 25.0 μg L^?1 with a correlation coefficient of 0.9981 and a detection limit of 0.1 μg L^?1. The relative standard deviation (RSD%) was less than 5.1% (n = 3) and the recovery values were in the range of 97.8 ± 0.9%. Finally, the proposed method was successfully applied for the analysis of MTBE in aqueous samples.     

分散微固相萃取/超高效液相色谱-高分辨质谱法测定茶叶中高氯酸盐

基于分散微固相萃取(DMSPE)技术,采用超高效液相色谱-高分辨质谱(UHPLC-HRMS)建立了茶叶中高氯酸盐的检测方法.样品采用乙腈提取,以PSA 和PCX 为吸附填料进行DMSPE 净化,采用Poroshell 120 PFP 色谱柱(50 mm×2.1 mm,1.9 μm)为分析柱,甲醇-1.0％乙酸水溶液作为...     

Effervescence‐assisted dispersive solid‐phase extraction using ionic‐liquid‐modified magnetic β‐cyclodextrin/attapulgite coupled with high‐performance liquid chromatography for fungicide detection in honey and juice

In this study, a simple effervescence‐assisted dispersive solid‐phase extraction method was developed to detect fungicides in honey and juice. Most significantly, an innovative ionic‐liquid‐modified magnetic β‐cyclodextrin/attapulgite sorbent was used because its large specific surface area enhanced the extraction capacity and also led to facile separation. A one‐factor‐at‐a‐time approach and orthogonal design were employed to optimize the experimental parameters. Under the optimized conditions, the entire extraction procedure was completed within 3 min. In addition, the calibration curves exhibited good linearity, and high enrichment factors were achieved for pure water and honey samples. For the honey samples, the extraction efficiencies for the target fungicides ranged from 77.0 to 94.3% with relative standard deviations of 2.3–5.44%. The detection and quantitation limits were in the ranges of 0.07–0.38 and 0.23–1.27 μg/L, respectively. Finally, the developed technique was successfully applied to real samples, and satisfactory results were achieved. This analytical technique is cost‐effective, environmentally friendly, and time‐saving.     

Dispersive solid-phase extraction combined with dispersive liquid-liquid microextraction for the determination of polybrominated diphenyl ethers in plastic bottled beverage by GC-MS

A simple, inexpensive and reliable analytical method was developed for the determination of polybrominated diphenyl ethers (PBDEs) in polyethylene terephthalate (PET) bottled beverage using GC‐MS. The sample pretreatment using dispersive solid‐phase extraction (DSPE) for removing matrix and dispersive liquid–liquid microextraction (DLLME) for enriching analytes was performed. For the DSPE, different sorbents such as primary amine, secondary amine, C₁₈ and graphitized carbon black were tested for different sample matrices. By means of DSPE, 60–89% of the sample matrices could be removed. Acetonitrile solution obtained by DSPE cleanup was directly used as the dispersant for the subsequent DLLME, which made the combination of the DSPE with the DLLME much more straightforward. Under the optimal conditions, the enrichment factors (EFs) of PBDEs ranged from 199 to 292. Using matrix‐matched calibration, correlation coefficients above 0.994 were found and LODs ranged from 0.0023 to 0.15 μg/L. The recoveries were between 80 and 117% for beverages spiked at three different concentrations (1.0, 5.0 and 10 μg/L) with RSDs ranging from 3.7 to 14.7% (n=5). The results indicated that the combination of DSPE with DLLME was a powerful sample preparation tool for analysis of ultratrace analytes in complicated matrices.     

分散液相微萃取-高效液相色谱法测定水和土壤中多环芳烃

以二硫化碳为萃取剂,丙酮为分散剂对水样和土壤样中残留的多环芳烃进行分散液相微萃取。提取液供高效液相色谱仪的二极管阵列检测器和荧光检测器测定。选用LiChrospherPAH色谱柱作为固定相,用乙腈和水以不同比例混合的溶液作为流动相进行梯度淋洗。在优化的试验条件下,对合成水样中多环芳烃的富集倍数达220～560倍,16种多环芳烃可有效分离并测定。16种多环芳烃的检出限(3S/N)在0.002～0.05μg.L-1之间。用标准加入法测得回收率在64%～108%之间,测定值的相对标准偏差(n=7)在2.0%～7.8%之间。     

Trace Analysis of Methyl Tert‐butyl Ether in Water Samples Using New Ultrasound‐assisted Dispersive Liquid‐liquid Microextraction and Gas Chromatography‐flame Ionization Detection

In this study, simple and efficient ultrasound‐assisted dispersive liquid‐liquid microextraction combined with gas chromatography (GC) was developed for the preconcentration and determination of methyl‐tert‐butyl ether (MTBE) in water samples. One hundred microliters of benzyl alcohol was injected slowly into 10 mL home‐designed centrifuge glass vial containing an aqueous sample with 30% (w/v) of NaCl that was located inside the ultrasonic water bath. The formed emulsion was centrifuged and 2 μL of separated benzyl alcohol was injected into a gas chromatographic system equipped with a flame ionization detector (GC‐FID) for analysis. Several factors influencing the extraction efficiency such as the nature and volume of organic solvent, extraction temperature, ionic strength and centrifugation times were investigated and optimized. Using optimum extraction conditions a detection limit of 0.05 μg L^‐1 and a good linearity (r² = 0.998) in a calibration range of 0.1‐500 μg L^‐1 were achieved. This proposed method was successfully applied to the analysis of MTBE in tap, well and a ground water sam ple contaminated by leaking gasoline from an underground storage tank (LUST) in a gasoline service station.     

Dispersive solid‐phase extraction followed by vortex‐assisted dispersive liquid–liquid microextraction based on the solidification of a floating organic droplet for the determination of benzoylurea insecticides in soil and sewage sludge

A novel dispersive solid‐phase extraction combined with vortex‐assisted dispersive liquid–liquid microextraction based on solidification of floating organic droplet was developed for the determination of eight benzoylurea insecticides in soil and sewage sludge samples before high‐performance liquid chromatography with ultraviolet detection. The analytes were first extracted from the soil and sludge samples into acetone under optimized pretreatment conditions. Clean‐up of the extract was conducted by dispersive solid‐phase extraction using activated carbon as the sorbent. The vortex‐assisted dispersive liquid–liquid microextraction based on solidification of floating organic droplet procedure was performed by using 1‐undecanol with lower density than water as the extraction solvent, and the acetone contained in the solution also acted as dispersive solvent. Under the optimum conditions, the linearity of the method was in the range 2–500 ng/g with correlation coefficients (r) of 0.9993–0.9999. The limits of detection were in the range of 0.08–0.56 ng/g. The relative standard deviations varied from 2.16 to 6.26% (n = 5). The enrichment factors ranged from 104 to 118. The extraction recoveries ranged from 81.05 to 97.82% for all of the analytes. The good performance has demonstrated that the proposed methodology has a strong potential for application in the multiresidue analysis of complex matrices.     

Solid‐phase purification and extraction for the determination of trace neonicotinoid pesticides in tea infusion

An analytical protocol that includes solid‐phase purification and extraction is successfully developed for the determination of trace neonicotinoid pesticides in tea infusion. The method consists of a purification on amino‐functionalized mesoporous silica SBA‐15 followed by a solid‐phase extraction based on graphene oxide before ultra high performance liquid chromatography with tandem mass spectrometry analysis. Parameters that significantly affected the extraction of the neonicotinoids onto graphene oxide, such as the amount of adsorbent, extraction time, pH, elution solvent, etc. were optimized. The amino‐functionalized mesoporous silica SBA‐15 has been proved to be an efficient adsorbent for removal of polyphenols especially catechins from tea infusion. Graphene oxide exhibits a very rapid adsorption rate (within 10 min) and high adsorption capacities for neonicotinoids at low initial concentration (0.01–0.5 mg/L). The analysis method gave a good determination coefficient (r² > 0.99) for each pesticide and high recoveries in the range of 72.2–95.0%. Powder X‐ray diffraction, Raman spectroscopy, transmission electron microscopy, and UV‐vis spectroscopy were utilized to identify the structure and morphology of graphene oxide. The adsorption driving force of neonicotinoids on graphene oxide mainly depends on π–π electron donor–acceptor interaction and electrostatic interaction.     

Extraction of phenolic compounds from water samples by dispersive micro‐solid‐phase extraction

In this article, the use of magnetically separable sorbent polyaniline/silica‐coated nickel nanoparticles is evaluated under a dispersive micro‐solid‐phase extraction approach for the extraction of phenolic compounds from water samples. The sorbent was prepared by in situ chemical polymerization of aniline on the surface of silica‐modified nickel nanoparticles and was characterized by Fourier transform infrared spectroscopy, transmission electron microscopy, X‐ray powder diffraction, scanning electron microscopy, energy‐dispersive X‐ray spectrometry, and vibrating sample magnetometry. Effective variables such as amount of sorbent (milligrams), pH and ionic strength of sample solution, volume of eluent solvent (microliters), vortex, and ultrasonic times (minutes) were investigated by fractional factorial design. The significant variables optimized by a Box–Behnken design were combined by a desirability function. Under the optimized conditions, the calibration graphs of analytes were linear in a concentration range of 0.02–100 μg/mL, and with correlation coefficients more than 0.999. The limits of detection and quantification were in the ranges of 10–23 and 33–77 μg/L, respectively. This procedure was successfully employed in the determination of target analytes in spiked water samples; the relative mean recoveries ranged from 96 to 105%.     

Development of a Sensitive Method for the Determination of 4‐(Methylnitrosamino)‐1‐(3‐pyridyl)‐1‐butanol in Human Urine Using Solid‐phase Extraction Combined with Ultrasound‐assisted Dispersive Liquid–liquid Microextraction and LC‐MS/MS Detection

An efficient and sensitive analytical method based on molecularly imprinted solid‐phase extraction (MISPE) and reverse‐phase ultrasound‐assisted dispersive liquid–liquid microextraction (USA‐DLLME) coupled with LC–MS/MS detection was developed and validated for the analysis of urinary 4‐(methylnitrosamino)‐1‐(3‐pyridyl)‐1‐butanol (NNAL), a tobacco‐specific nitrosamine metabolite. The extraction performances of NNAL on three different solid‐phase extraction (SPE) sorbents including the hydrophilic‐lipophilic balanced sorbent HLB, the mixed mode cationic MCX sorbent and the molecularly imprinted polymers (MIP) sorbent were evaluated. Experimental results showed that the analyte was well retained with the highest extraction recovery and the optimum purification effect on MIP. Under the optimized conditions of MIP and USA‐DLLME, an enrichment factor of 23 was obtained. Good linearity relationship was obtained in the range of 5‐1200 pg/mL with a correlation coefficient of 0.9953. The limit of detection (LOD) was 0.35 pg/mL. The recoveries at three spiked levels ranged between 88.5% and 93.7%. Intra‐ and inter‐day relative standard deviations varied from 3.6% to 7.4% and from 5.4% to 9.7%, respectively. The developed method combing the advantages of MISPE and DLLME significantly improves the purification and enrichment of the analyte and can be used as an effective approach for the determination of ultra‐trace NNAL in complex biological matrices.     

Determination of hexabromocyclododecane isomers in sewage sludge by LC‐MS/MS

A method has been developed to determine α, β and γ diastereoisomers of hexabromocyclododecane (HBCD), a brominated flame retardant, in sewage sludge, based on the ultrasonic‐assisted extraction (UAE) of samples with dichloromethane–ACN (1:1) and the subsequent clean‐up of extracts by dispersive solid phase extraction with primary–secondary amine. Levels of HBCD diastereoisomers were determined by LC coupled with ESI MS/MS. Evaluation of the matrix effect showed a high ion suppression for all the diastereoisomers studied, which was counteracted by using a mixture of labelled HBCD diastereoisomers as internal standards. This method yielded recoveries in the range of 79.6–112.5% with SDs equal or lower than 9.1 The limits of detection were 0.3 ng/g for α‐ and β‐HBCD and 0.2 ng/g for γ‐HBCD. The developed method was successfully applied to 19 sludge samples collected from the province of Madrid (Spain). In most of the samples, β‐HBCD was below the method detection limit, whereas α‐ and γ‐HBCD were quantified in all of the sludge samples, and γ‐HBCD was the predominant diastereoisomer in 63% of the analyzed samples and α‐HBCD predominated in the rest.