高效液相色谱-串联质谱法检测婴幼儿血清中4种双酚类环境激素残留

目前,双酚类化合物是重要的工业原料,常用来制造塑料(奶)瓶、幼儿用吸口杯、食品和饮料(奶粉)罐内侧涂层,其具有类似雌激素的作用,摄入低剂量的双酚类物质便会引起机体尤其婴幼儿体内激素水平的调节。建立了一种同时测定婴幼儿血清中双酚A(BPA)、双酚B(BPB)、双酚F(BPF)、双酚S (BPS)4种双酚类环境激素的高效液相色谱-串联质谱法(HPLC-MS/MS)。以甲基叔丁基醚(MTBE)为提取溶剂,采用液液萃取的方法进行样品处理,同时对影响4种双酚类环境激素提取效率的提取溶剂、提取时间、提取溶剂体积等影响因素进行了优化。100 μL血清样本在40 ℃下经400 μL MTBE提取15 min后,采用Waters ACQUITY UPLC BEH C18柱(50 mm×2.1 mm, 1.7 μm)进行分离,以超纯水和含0.5 mmol/L乙酸铵的甲醇溶液为流动相进行梯度洗脱,流速为0.2 mL/min,采用电喷雾电离、负离子模式扫描,在多反应监测(MRM)模式下测定。BPA、BPB、BPS在0.25~100 μg/L范围内线性关系良好,BPF在1~00 μg/L范围内线性关系良好,相关系数为0.9929~0.9959;方法的检出限分别为0.05、0.05、0.05、0.5 μg/L;在3个添加水平(5、20、100 μg/L)下,4种目标化合物的回收率为84.56%~104.43%,相对标准偏差小于10%。应用该方法对150例婴幼儿血清样品进行检测,结果表明:BPA、BPF、BPS在男童和女童血清中的检出率分别为90.67%和89.33%、6.67%和1.33%、5.33%和16.00%, BPB未被检出。该方法操作简单,回收率好,精密度高,适用于婴幼儿血清中4种双酚类环境激素的同时测定。     

Quantification of free and total bisphenol A and bisphenol B in human urine by dispersive liquid-liquid microextraction (DLLME) and heart-cutting multidimensional gas chromatography-mass spectrometry (MD-GC/MS)

A novel method combining dispersive liquid-liquid microextraction (DLLME) and heart-cutting multidimensional gas chromatography coupled to mass spectrometry was developed for the determination of free and total bisphenol A (BPA) and bisphenol B (BPB) in human urine samples. The DLLME procedure combines extraction, derivatization and concentration of the analytes into one step. Several important variables influencing the extraction efficiency and selectivity such as nature and volume of extractive and dispersive solvents as well as the amount of acetylating reagent were investigated. The temperature and time to hydrolyze BPA and BPB conjugates with a β-glucuronidase and sulfatase enzyme preparation were also studied. Under the optimized conditions good efficiency extraction (71-93%) and acceptable total DLLME yields (56-77%) were obtained for both analytes. Matrix-matched calibration curves were linear with correlation coefficients higher than 0.996 in the range level 0.1-5 μg/l, and the relative standard deviations (%RSD) were lower than 20% (n = 6). The limits of detection were 0.03 and 0.05 μg/l for BPA and BPB, respectively. The applicability of the proposed method for determining urinary free and total BPA and BPB was assessed by analyzing the human urine of a group of 20 volunteers. Free BPA was detected in 45% of the sample whereas total BPA was detected in 85% of the samples at concentrations ranging between 0.39 and 4.99 μg/l. BPB was detected in conjugated form in two samples.     

Determination of bisphenol A and bisphenol B in canned seafood combining QuEChERS extraction with dispersive liquid–liquid microextraction followed by gas chromatography–mass spectrometry

A new simple and reliable method combining an acetonitrile partitioning extractive procedure followed by dispersive solid-phase cleanup (QuEChERS) with dispersive liquid–liquid microextraction (DLLME) and further gas chromatography mass spectrometry analysis was developed for the simultaneous determination of bisphenol A (BPA) and bisphenol B (BPB) in canned seafood samples. Besides the great enrichment factor provided, the final DLLME extractive step was designed in order to allow the simultaneous acetylation of the compounds required for their gas chromatographic analysis. Tetrachloroethylene was used as extractive solvent, while the acetonitrile extract obtained from QuEChERS was used as dispersive solvent, and anhydride acetic as derivatizing reagent. The main factors influencing QuEChERS and DLLME efficiency including nature of QuEChERS dispersive-SPE sorbents, amount of DLLME extractive and dispersive solvents and nature and amount of derivatizing reagent were evaluated. DLLME procedure provides an effective enrichment of the extract, allowing the required sensitivity even using a single quadropole MS as detector. The optimized method showed to be accurate (>68?% recovery), reproducible (<21?% relative standard deviation) and sensitive for the target analytes (method detection limits of 0.2?μg/kg for BPA and 0.4?μg/kg for BPB). The screening of several canned seafood samples commercialized in Portugal (total?=?47) revealed the presence of BPA in more than 83?% of the samples with levels ranging from 1.0 to 99.9?μg/kg, while BPB was found in only one sample at a level of 21.8?μg/kg.     

高通量固相萃取-超高效液相色谱-串联质谱法测定人尿中8种环境酚类内分泌干扰物

建立了人尿中8种环境酚类化合物的96孔板固相萃取-超高效液相色谱-串联质谱(96-well SPE LC-MS/MS)检测方法,其中包括7种双酚类化合物和三氯生。尿样解冻到室温,经β-葡萄糖醛酸苷肽酶/芳基磺酸酯酶37 ℃过夜酶解。实验比较了3种96孔板固相萃取柱和不同淋洗条件对人尿样的净化效果和目标化合物的回收率。结果显示,采用Oasis HLB 96孔板(60 mg)对样品进行萃取和用30%(v/v)乙腈水溶液进行淋洗净化的纯化效果最好。纯化后目标物用甲醇溶液洗脱,经氮气吹干,用0.5 mL甲醇-水(1∶1, v/v)溶液定容,目标化合物用UPLC-MS/MS进行检测。比较了2种分析柱(C₁₈和T3分析柱)以及不同的有机流动相对分离样品中目标物的影响。结果显示,以BEH C₁₈(100 mm×2.1 mm, 1.7 μm)作为分析柱,乙腈/水作为流动相,以流速0.3 mL/min梯度洗脱时,目标物的分离效果最好。质谱条件选择串联质谱负离子电喷雾(ESI^-)多反应监测模式(MRM)进行检测。对样品的基质效应进行评估发现,双酚A、双酚F、双酚S、双酚B和双酚AF的绝对基质效应为3.47%~15.32%,不需要补偿措施;四氯双酚A、四溴双酚A和三氯生的绝对基质效应分别是49.58%(中等基质效应)、71.99%和86.93%(强基质效应),均需要补偿效应。因此,该方法采用了一一对应的同位素内标法抵消基质效应。用6份实际尿样基质评估相对基质效应,8种内标的峰面积的相对标准偏差为3.63%~9.06%,说明相对基质效应稳定。在优化条件下,双酚A和双酚AF在0.50~50 μg/L内、四氯双酚A和双酚S在0.05~50 μg/L内、双酚F和四溴双酚A在0.01~50 μg/L内、双酚B在1.00~50 μg/L内、三氯生在5.00~200 μg/L内线性关系良好,相关系数大于0.9995。方法检出限为0.002~1.09 μg/L,定量限为0.007~3.63 μg/L。3个加标水平的加标回收率为81.0%~101.9%,日内精密度为0.4%~19.4%,日间精密度为2.5%~17.8%。应用该方法对2019-2020年采集的北京地区64份尿样进行测定,结果发现8种目标分析物中,除双酚B和双酚AF未检出外,其余均有检出,其中双酚A和双酚S的检出率最高,分别为100%和96.9%。三氯生、四溴双酚A、四氯双酚A和双酚F的检出率分别为57.8%、46.9%、23.4%和21.9%。尿样中8种目标物含量的中位值以降序排列分别为1.44 μg/L(三氯生)、0.69 μg/L(双酚A)、0.086 μg/L(双酚S)、0.0032 μg/L(四溴双酚A)、0.00050 μg/L (四氯双酚A)、0.00 μg/L(双酚F、双酚B和双酚AF)。以上尿样检测结果显示,北京市居民存在普遍的环境酚类化合物暴露,值得关注。该方法操作简单,定量准确,样品需求量小,有机试剂消耗少,适合大批量样本的测定。     

Analysis of bisphenols in soft drinks by on-line solid phase extraction fast liquid chromatography-tandem mass spectrometry

In this study, an automated on-line solid-phase extraction coupled to fast liquid chromatography–tandem mass spectrometry (on-line SPE fast LC–MS/MS) method was developed for the simultaneous analysis of bisphenol A (BPA), bisphenol F (BPF), bisphenol E (BPE), bisphenol B (BPB) and bisphenol S (BPS) in canned soft drinks without any previous sample treatment. A C18 (12 μm particle size) loading column was used for the SPE on-line preconcentration before the liquid chromatography baseline separation of bisphenol compounds using a C18 Fused-Core™ (50 mm × 2.1 mm i.d.) column, which took less than 3 min. Gradient elution and heated electrospray were used to reduce matrix effect and improve ionization efficiency. To select the most intense and selective transitions, fragmentation studies were performed by multiple-stage mass spectrometry in an ion trap mass analyzer and tandem mass spectrometry in a triple quadrupole instrument, this latter instrument being used for quantitation in SRM mode. Quality parameters of the method were established and we obtained a simple, fast, reproducible (RSD values lower than 10%) and accurate (precision higher than 93%) method for the analysis of bisphenols in canned soft drinks at the ng L⁻¹ level using matrix-matched calibration.     

固相萃取技术在食品痕量残留和污染分析中的应用

食品痕量残留和污染分析中,样品的前处理极为重要,也是其难点所在。由于食品和农产品样品的多样性和复杂性,目前还没有一种前处理技术能够适合所有情况下的所有样品。本文对近年来发展起来的新型固相萃取技术如固相微萃取、搅拌棒吸附萃取、基质固相分散萃取、分子印迹固相萃取、免疫亲和固相萃取、整体柱固相萃取、碳纳米管固相萃取等在食品痕量残留和污染分析中的应用进行了综述,对未来的发展前景作了展望。     

Measurement of bisphenol A and bisphenol B levels in human blood sera from healthy and endometriotic women

A sensitive HPLC method with fluorescence detection was developed for the determination of bisphenol A (BPA) and bisphenol B (BPB) in human blood serum. The detection limits of the method were 0.18 and 0.20 ng/mL for BPA and BPB, respectively. A single‐step liquid–liquid extraction was used for the pre‐treatment of serum samples. The recoveries of BPA and BPB spiked to sera were 85.6 and 87.7%, respectively. The analyses of sera from both healthy and endometriotic women emphasized the absence of bisphenols in all the control cases (11 women), whereas BPA was found in 30 sera (51.7%) and BPB was found in 16 sera (27.6%) in the group of 58 patients with endometriosis; in nine of such sera BPA and BPB were present simultaneously. Only relatively to the sera quantitated, BPA concentrations ranged from 0.79 to 7.12 ng/mL (mean concentration 2.91 ± 1.74 ng/mL), whereas BPB concentrations ranged from 0.88 to 11.94 ng/mL (mean concentration 5.15 ± 4.16 ng/mL). Therefore, the presence of at least one of the two bisphenols was verified in a percentage as high as 63.8% in the sera from endometriotic women, suggesting the existence of a relationship between endometriosis and BPA and/or BPB exposure. Indeed, it is well known that bisphenols can work as xenoestrogens, owing to their structural similarity to natural and synthetic estrogens (e.g. estradiol and dietilstilbestrol). However, further studies are necessary to confirm this hypothesis and to assess the actual dose at which exposures to bisphenols are able to increase the sensitivity of the endometriotic cells to estradiol. Copyright © 2009 John Wiley & Sons, Ltd.     

Continuous solid-phase extraction and preconcentration of bisphenol A in aqueous samples using molecularly imprinted columns

A bisphenol A (BPA) molecularly imprinted polymer, the composition of which was optimised using a chemometric approach, has been applied to the selective preconcentration of the template from aqueous samples. The selectivity of the polymer toward BPA and related compounds was evaluated chromatographically. The BPA-imprinted polymer was packed in a column and used for continuous on-column solid-phase extraction (MISPE) of aqueous samples followed by subsequent analysis by HPLC with fluorescence detection of the eluted fractions. The composition of the washing solvent applied in the MISPE procedure was optimised to favour the specific interactions of the MIP with BPA and to remove the non-selectively bound matrix components. The MISPE method has proven to be effective for selective preconcentration of BPA in aqueous samples (recoveries >84% obtained in the eluate for 10–100 mL sample volumes) enabling detection and quantification limits of 1.0 and 3.3 ng mL^–1, respectively (based on 25 mL sample size). Analytical recoveries were between 92 and 101% for river water samples spiked with known amounts of BPA (30, 60, and 80 ng mL^–1); relative standard deviations (RSD) were lower than 5.0%.     

Simultaneous isolation of six fluoroquinolones in serum samples by selective molecularly imprinted matrix solid-phase dispersion

A simple and sensitive method for the simultaneous determination of six fluoroquinolones from serum samples was developed by selective molecularly imprinted matrix solid-phase dispersion (MI-MSPD) coupled with chromatographic separation. By using ethylene glycol dimethacrylate as crosslinker and reformative methanol–water system as reaction medium, the improved water-compatible imprinted polymers were synthesized which show higher affinity to template and its analogues in aqueous environment. The molecularly imprinted polymers (MIPs) were applied as the selective dispersant of matrix solid-phase dispersion (MSPD) could selectively extracted the six fluoroquinolones from serum, while interferences originated from serum matrices were eliminated simultaneously. Good linearity was obtained in a range of 0.05–100 μg mL⁻¹ with the correlation coefficients >0.999. The average recoveries of the six fluoroquinolones at four different spiked levels (0.25–10 μg mL⁻¹) were ranged from 72.2% to 114.1% with the relative standard deviations less than 6.6%. This method is simple and sensitive, and can be used as an alternative tool to the existing HPLC methods for analyzing the residues of fluoroquinolones in biological samples.     

Simultaneous determination of phenolic xenoestrogens by solid-phase extraction and high-performance liquid chromatography with fluorescence detection.

A highly sensitive and selective method for simultaneous determination of some hydroxyl group-containing endocrine disruptors, including bisphenol A (BPA), bisphenol B (BPB), bisphenol E (BPE), bisphenol F (BPF) and 4-nonylphenol (4-NP), was developed. The method consists of precolumn derivatization of the analytes, solid-phase extraction (SPE) and subsequent chromatographic analysis by high-performance liquid chromatography (HPLC) with fluorescence detection. 4,4'-Cyclohexylidenebisphenol (BPZ) was used as an internal standard. Derivatization was carried out using 4-(4,5-diphenyl-1H-imidazol-2-yl)benzoyl chloride (DIB-Cl) as a label. Parameters of the derivatization reaction (temperature, time, concentration of reagent, stability, etc.) and of the solid-phase extraction (recovery, solvent, etc.) were studied in detail. Detection limits of compounds studied in standard solutions ranged from 0.08-1.3 ppb (ng/ml). The proposed method was successfully applied to plastic samples; BPA was found in both polycarbonate and polyvinyl chloride plastics, while 4-NP was found in plastics made of polyvinyl chloride and another polymer.     

Miniaturized Salting-Out Assisted Liquid-Liquid Extraction Combined with Disposable Pipette Extraction for Fast Sample Preparation of Neonicotinoid Pesticides in Bee Pollen

As the main source of nutrients for the important pollinator honeybee, bee pollen is crucial for the health of the honeybee and the agro-ecosystem. In the present study, a new sample preparation procedure has been developed for the determination of neonicotinoid pesticides in bee pollen. The neonicotinoid pesticides were extracted using miniaturized salting-out assisted liquid-liquid extraction (mini-SALLE), followed by disposable pipette extraction (DPX) for the clean-up of analytes. Effects of DPX parameters on the clean-up performance were systematically investigated, including sorbent types (PSA, C18, and silica gel), mass of sorbent, loading modes, and elution conditions. In addition, the clean-up effect of classical dispersive solid-phase extraction (d-SPE) was compared with that of the DPX method. Results indicated that PSA-based DPX showed excellent clean-up ability for the high performance liquid chromatography (HPLC) analysis of neonicotinoid pesticides in bee pollen. The proposed DPX method was fully validated and demonstrated to provide the advantage of simple and rapid clean-up with low consumption of solvent. This is the first report of DPX method applied in bee pollen matrix, and would be valuable for the development of a fast sample preparation method for this challenging and important matrix.     

Matrix effects in pesticide multi-residue analysis by liquid chromatography-mass spectrometry

Three sample preparation methods: Luke method (AOAC 985.22), QuEChERS (quick, easy, cheap, effective, rugged and safe) and matrix solid-phase dispersion (MSPD) were applied to different fruits and vegetables for analysis of 14 pesticide residues by high-performance liquid chromatography with electrospray ionization-mass spectrometry (HPLC/ESI/MS). Matrix effect, recovery and process efficiency of the sample preparation methods applied to different fruits and vegetables were compared. The Luke method was found to produce least matrix effect. On an average the best recoveries were obtained with the QuEChERS method. MSPD gave unsatisfactory recoveries for some basic pesticide residues. Comparison of matrix effects for different apple varieties showed high variability for some residues. It was demonstrated that the amount of co-extracting compounds that cause ionization suppression of aldicarb depends on the apple variety as well as on the sample preparation method employed.     

Occurrence of Fungicides in Vineyard and the Surrounding Environment

Seventeen fungicides were determined in different matrices from vineyard areas, including vine leaves, soils, grapes and water, using gas chromatography coupled to tandem mass spectrometry (GC-MS/MS). For leaf analysis, ultrasound-assisted extraction (UAE) was performed evaluating different solvents. UAE was compared with other extraction techniques such as vortex extraction (VE) and matrix solid-phase dispersion (MSPD). The performance of the UAE method was demonstrated on vine leaf samples and on other types of samples such as tea leaves, underlining its general suitability for leaf crops. As regards other matrices, soils were analyzed by UAE and microwave-assisted extraction (MAE), grapes by UAE and waters by SPE using cork as the sorbent. The proposed method was applied to 17 grape leaf samples in which 14 of the target fungicides were detected at concentrations up to 1000 μg g⁻¹. Furthermore, the diffusion and transport of fungicides was demonstrated not only in crops but also in environmental matrices.     

Application of Covalent Organic Porous Polymers-Functionalized Basalt Fibers for in-Tube Solid-Phase Microextraction

To establish an online analytical method towards estrogenic pollutants, a covalent organic porous polymer (COP) was in-situ synthesized on the surface of basalt fibers (BFs) for in-tube solid-phase microextraction (IT-SPME). The extraction tube, obtained via placing the modified BFs into a polyetheretherketone tube, was combined with high-performance liquid chromatography (HPLC) to achieve online IT-SPME-HPLC analysis. The important parameters, including sampling volume, sampling rate, organic solvent content and desorption time, were carefully investigated. Under the optimized conditions, the online analytical method was established for five estrogenic targets, with low limits of detection (0.001–0.005 μg/L), high enrichment factors (1800–2493), wide linear ranges (0.003–20, 0.015–20 μg/L) and satisfactory repeatability. It was successfully applied to detect five estrogens in a wastewater sample and a water sample in a polycarbonate cup. The BFs functionalized with COPs displayed excellent extraction effect for estrogenic pollutants, furthermore it has great potential in sample preparation or other fields.     

A simple approach for ultrasensitive detection of bisphenols by multiplexed surface-enhanced Raman scattering

Bisphenol A (BPA) is well known for its use in plastic manufacture and thermal paper production despite its risk of health toxicity as an endocrine disruptor in humans. Since the publication of new legislation regarding the use of BPA, manufacturers have begun to replace BPA with other phenolic molecules such as bisphenol F (BPF) and bisphenol B (BPB), but there are no guarantees regarding the health safety of these compounds at this time. In this context, a very simple, cheap and fast surface-enhanced Raman scattering (SERS) method was developed for the sensitive detection of these molecules in spiked tap water solutions. Silver nanoparticles were used as SERS substrates. An original strategy was employed to circumvent the issue of the affinity of bisphenols for metallic surfaces and the silver nanoparticles surface was functionalized using pyridine in order to improve again the sensitivity of the detection. Semi-quantitative detections were performed in tap water solutions at a concentrations range from 0.25 to 20 μg L⁻¹ for BPA and BPB and from 5 to 100 μg L⁻¹ for BPF. Moreover, a feasibility study for performing a multiplex-SERS detection of these molecules was also performed before successfully implementing the developed SERS method on real samples.     

Silibinin and Naringenin against Bisphenol A-Induced Neurotoxicity in Zebrafish Model—Potential Flavonoid Molecules for New Drug Design,Development, and Therapy for Neurological Disorders

Bisphenol A (BPA), a well-known xenoestrogen, is commonly utilised in the production of polycarbonate plastics. Based on the existing evidence, BPA is known to induce neurotoxicity and behavioural issues. Flavonoids such as silibinin and naringenin have been shown to have biological activity against a variety of illnesses. The current research evaluates the neuropharmacological effects of silibinin and naringenin in a zebrafish model against neurotoxicity and oxidative stress caused by Bisphenol A. In this study, a novel tank diving test (NTDT) and light–dark preference test (LDPT) were used in neurobehavioural investigations. The experimental protocol was planned to last 21 days. The neuroprotective effects of silibinin (10 μM) and naringenin (10 μM) in zebrafish (Danio rerio) induced by BPA (17.52 μM) were investigated. In the brine shrimp lethality assay, the 50% fatal concentrations (LC₅₀) were 34.10 μg/mL (silibinin) and 91.33 μg/mL (naringenin) compared to the standard potassium dichromate (13.15 μg/mL). The acute toxicity investigation found no mortality or visible abnormalities in the silibinin- and naringenin-treated groups (LC₅₀ > 100 mg/L). The altered scototaxis behaviour in LDPT caused by BPA was reversed by co-supplementation with silibinin and naringenin, as shown by decreases in the number of transitions to the light zone and the duration spent in the light zone. Our findings point to BPA’s neurotoxic potential in causing altered scototaxis and bottom-dwelling behaviour in zebrafish, as well as the usage of silibinin and naringenin as potential neuroprotectants.     

Determination of Anthelmintic and Antiprotozoal Drug Residues in Fish Using Liquid Chromatography-Tandem Mass Spectrometry

The objective of this study is to develop a comprehensive and simple method for the simultaneous determination of anthelmintic and antiprotozoal drug residues in fish. For sample preparation, we used the “quick, easy, cheap, effective, rugged, and safe” (QuEChERS) method with a simple modification. The sample was extracted with water and 1% formic acid in acetonitrile/methanol (MeCN/MeOH) (95:5, v/v), followed by phase separation (salting out) with MgSO₄ and NaCl (4:1, w/w). After centrifugation, an aliquot of the extract was purified by dispersive solid-phase extraction (d-SPE) prior to liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. The method was validated at three concentration levels for all matrices, in accordance with the Codex guidelines (CAC/GL-71). Quantitative analysis was performed using the method of matrix-matched calibration. The recoveries were between 60.6% and 119.9%, with coefficients of variation (CV) <30% for all matrices. The limit of quantitation (LOQ) of the method ranged from 0.02 μg kg⁻¹ to 4.8 μg kg⁻¹ for all matrices. This comprehensive method can be used for the investigation of both anthelmintic and antiprotozoal drugs belonging to different chemical families in fishery products.     

Use of solid-phase microextraction for the analysis of bisphenol A and bisphenol A diglycidyl ether in food simulants

A new method has been developed to simultaneously analyse bisphenol A (BPA) and bisphenol A diglycidyl ether (BADGE) in aqueous based food simulants. The method consists on direct immersion solid-phase microextraction (SPME) of the analytes from the liquid matrix and subsequent chromatographic analysis by gas chromatography-mass spectrometry. Using the proposed method, a whole analysis (including chromatographic step) can be completed in less than 40 min, with minimum sample handling. The SPME method shows good analytical performance for simultaneous BPA and BADGE analysis, except for BADGE determination in the aqueous alcohol (simulant C) solution. Detection limits ranging from 0.1 to 2.0 ng/g for BPA and from 13 to 15 ng/g from BADGE were obtained, with a linear range from the low-ng/g to several-microg/g range for BPA and from 0.1 microg/g to 40 microg/g for BADGE. A possible optimisation method has been also developed and introduced.     

New method based on combining ultrasonic assisted miniaturized matrix solid-phase dispersion and homogeneous liquid-liquid extraction for the determination of some organochlorinated pesticides in fish

In this study, ultrasonic assisted miniaturized matrix solid-phase dispersion (US-MMSPD) combined with homogeneous liquid–liquid extraction (HLLE) has been developed as a new method for the extraction of organochlorinated pesticides (OCPs) in fish prior to gas chromatography with electron capture detector (GC-ECD). In the proposed method, OCPs (heptachlor, aldrin, DDE, DDD, lindane and endrin) were first extracted from fish sample into acetonitrile by US-MMSPD procedure, and the extract was then used as consolute solvent in HLLE process. Optimal condition for US-MMSPD step was as follows: volume of acetonitrile, 1.5 mL; temperature of ultrasound, 40 °C; time of ultrasound, 10 min. For HLLE step, optimal results were obtained at the following conditions: volume of chloroform, 35 μL; volume of aqueous phase, 1.5 mL; volume of double distilled water, 0.5 mL; time of centrifuge, 10 min. Under the optimum conditions, the enrichment factors for the studied compounds were obtained in the range of 185–240, and the overall recoveries were ranged from 39.1% to 81.5%. The limits of detection were 0.4–1.2 ng g⁻¹ and the relative standard deviations for 20 ng g⁻¹ of the OCPs, varied from 3.2% to 8% (n = 4). Finally, the proposed method has been successfully applied to the analysis of the OCPs in real fish sample, and satisfactory results were obtained.     

Preparation of functionalized magnetic nanoparticulate sorbents for rapid extraction of biphenolic pollutants from environmental samples

A new solid-phase extraction coupled with magnetic carrier technology was developed for extraction of bisphenol A (BPA) and diethylstilbestrol (DES) from water samples. The SPE sorbents, functionalized magnetic nanoparticles (Fe₃O₄@SiO₂/β-CD, core/shell), were synthesized in a two-stage system. The material was characterized by Fourier transform infrared spectroscopy, transmission electron microscopy, and a vibrating sample magnetometer. SPE extraction parameters, such as volume and pH of sample, adsorption time, and desorption conditions were optimized. Under selected conditions: 250 mL of water sample, 0.1 g of sorbents and elution with methanol (3 mL with 1% acetic acid), the extraction was completed in 25 min. SPE followed by HPLC was employed to determine BPA and DES in environmental samples. The developed method provided spiked recoveries of 80–105%, relative standard deviations of less than 7%, and LOD of BPA (20.0 ng/L) and DES (23.0 ng/L), respectively. The proposed method offered easy preparation of sorbents, rapid analysis, high enrichment yields, and reliable quantitative assay.