罐头食品中双酚A和双酚F环氧衍生物残留的高效液相色谱分析

建立了一种高效液相色谱分析罐头食品中双酚A(BPA)和双酚F(BPF)环氧衍生物的方法。样品经微波辅助萃取后过PPL(填料为苯乙烯-二乙烯苯(SDVB)聚合物)固相萃取柱进行净化试验。结果表明,微波辅助萃取法的提取效果理想;采用PPL固相萃取回收率在73.26%~104.98%,除杂效果明显。将微波辅助—PPL固相萃取净化法应用于多种食品进行分析,结果表明该方法适用于食品中双酚A和双酚F环氧衍生物残留分析。     

食品中核-壳型罗丹明6G磁性分子印迹固相萃取材料的制备及应用

结合磁性分离技术和表面分子印迹技术,以改性Fe3O4为核、罗丹明6G分子印迹聚合物膜为壳,制备核-壳型磁性分子印迹聚合物微纳米材料。研究其对罗丹明6G的吸附性能,探讨了吸附动力学、吸附等温线及分子识别性,并将它应用于食品中分离富集罗丹明6G。结果表明：所制备的核-壳型磁性分子印迹聚合物具有高吸附容量（表观最大吸附量达24.69 mg/g）、快速的结合动力学（20 min达吸附平衡）及显著的吸附选择性（印迹因子达4.20）。以其作为新型固相萃取材料,结合高效液相色谱检测,对加标食品样品中的罗丹明6G进行分离、纯化、检测,加标回收率为92.3%～99.2%;相对标准偏差为0.85%～1.12%;检出限为0.003 8 μg/mL。在外加磁场作用下分子印迹聚合物可快速与样品基质分离,提高了实验效率。本方法简单快速,可应用于食品中非法添加的罗丹明6G的分离检测。     

Simultaneous Determination of Aflatoxin B1, Bisphenol A,and 4-Nonylphenol in Peanut Oils by Liquid-Liquid Extraction Combined with Solid-Phase Extraction and Ultra-High Performance Liquid Chromatography-Tandem Mass Spectrometry

An analytical method based on liquid-liquid extraction combined with solid-phase extraction and isotope dilution-ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was well developed for simultaneous determination of aflatoxin B1 (AFB1), bisphenol A (BPA), and 4-nonylphenol (4-NP) in peanut oil. After adding isotope internal standards, the samples were firstly diluted by normal hexane and then extracted by acetonitrile and Carb/PSA solid-phase extraction cartridge in sequence to obtain the extracted solution. All the extracted solution was merged and was subsequently dried to near dryness by a mild nitrogen stream. Three target analytes were separated on a Phenomenex Luna C18 chromatographic column, quantified by an internal standard method and detected by ESI positive (ESI⁺) and negative (ESI^?) subsection acquisition modes under multi-reaction monitoring (MRM) conditions. Results demonstrated that the three target analytes exhibited excellent linearity in their corresponding concentration ranges of 0.1–100.0 μg/L with correlation coefficients all greater than 0.998. The corresponding method limits of quantitation (MLOQ, S/N?=?10) of AFB1, BPA, and 4-NP were 0.2, 1.0, and 2.0 μg/kg, respectively. Moreover, the mean recoveries for negative samples spiked at three concentration levels were calculated between 87.7 and 105.1% with relative standard deviation (RSD, n?=?6) ranging from 2.2 to 7.9% and the interday precision (n?=?5) ranging from 5.0 to 8.7%. Finally, the method was successfully applied to analyze 52 peanut oil samples, and AFB1 and 4-NP were detected in 43 samples with the concentrations in the ranges of 0.5–69.4 and 9.3–77.8 μg/kg, respectively. None of BPA was detected in any samples.     

Determination of free and conjugated forms of bisphenol A in human urine and serum by liquid chromatography-tandem mass spectrometry

Exposure of humans to bisphenol A (BPA), a widely used industrial chemical, is well-known. In humans and animals, conjugation of BPA molecule with glucuronide or sulfate is considered as a mechanism for detoxification. Nevertheless, very few studies have directly measured free, conjugated (e.g., glucuronidated), and substituted (e.g., chlorinated) forms of BPA in human specimens. In this study, free, conjugated (BPA glucuronide or BPAG and BPA disulfate or BPADS), and substituted (chlorinated BPA; mono- [BPAMC], di-[BPADC], and trichloride [BPATrC]) forms of BPA were determined in human urine and serum samples, using solid-phase extraction (SPE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) techniques. The instrumental calibration for each of the target compounds ranged from 0.01 to 100 ng/mL and showed excellent linearity (r > 0.99). The limits of quantification (LOQs) were 0.01 ng/mL for free BPA and 0.05 ng/mL for the conjugated and substituted BPA. Respective recoveries of the six target compounds spiked into water blanks and sample matrices (urine and serum), and passed through the entire analytical procedure, were 96 ± 14% and 105 ± 18% (mean ± SD) for urine samples and 87 ± 8% and 80 ± 13% for serum samples. The optimal recoveries of BPAG and BPADS in the analytical procedure indicted that no deconjugation occurred during the SPE procedure. The method was applied to measure six target chemicals in urine and serum samples collected from volunteers in Albany, New York. BPA and its derivatives were found in urine samples at concentrations ranging from < LOQ to a few tens of ng/mL. In serum, free and conjugated BPA were detected at sub ng/mL concentrations, whereas BPA chlorides were not detected. The urine and serum samples were also analyzed by enzymatic deconjugation and liquid-liquid extraction (LLE) for the determination of total BPA, and the results were compared with those measured by the SPE method. To our knowledge, this is the first report on the occurrence of BPAG and BPADS in human serum.     

Magnetic Dummy Template Silica Sol–Gel Molecularly Imprinted Polymer Nanospheres as Magnetic Solid-Phase Extraction Material for the Selective and Sensitive Determination of Bisphenol A in Plastic Bottled Beverages

In this study, a core–shell magnetic dummy molecularly imprinted polymer (MDMIP) was prepared with a novel and simple method. The imprinting layer was synthesized directly on the surface of Fe₃O₄ by only one step, which avoided further modification on the exterior of magnetic core. 4,4′-Dihydroxybiphenyl (DDBP) was used as dummy template instead of bisphenol A (BPA) to eliminate the effect of template leakage on quantitative analysis. When used as solid-phase extraction sorbent, a rapid, sensitive, and accurate method for the simultaneous extraction, concentration, and determination of trace BPA in plastic bottled beverage samples by MDMIP-SPE coupled with high-performance liquid chromatography (HPLC) was developed. Advantages of such method may be counted as the mild working temperature during the synthesis, simplicity of extraction procedure, avoidance of leakage of template, time-saving, and high binding capacity and affinity. Several parameters affecting the extraction efficiency of the analytes including the sorbent mass, the pH of sample solution, the HAc percentage in the elute, and the desorption time were investigated. Under optimized conditions, the calibration graph was linear over the range of 11.4–4560 ng mL^?1 with the limit of detection of 0.083 ng L^?1. In addition, the higher enrichment factors (400-fold) and good recoveries (88.6–99.5%) with relative standard deviation (RSD) values less than 9.5% were achieved. Moreover, the developed extraction protocol simplified the process of traditional solid-phase extraction (SPE) provided the possibility for separation and enrichment of BPA from complicated food matrices.     

高效液相色谱-三重四极杆串联质谱法研究塑料接触材料中酚类化合物向奶油中的迁移

建立奶油中14 种酚类化合物高效液相色谱-三重四极杆串联质谱的同时测定方法，研究裱花蛋糕塑料接触材料中酚类化合物在真实样品奶油中的迁移情况。塑料样品经奶油浸泡，乙腈-甲醇提取，T3色谱柱分离，以负离子-多反应监测模式进行测定，基质外标法定量；分析双酚A（bisphenol A，BPA）和4-壬基酚（4-nonylphenol，4-NP）在奶油样品中的迁移规律，用于14 种酚类化合物在奶油中迁移量的测定研究。结果表明，14 种酚类化合物的检出限为0.15～0.75 μg/kg，定量限为0.5～2.5 μg/kg，线性关系良好，相关系数均大于0.99；酚类物质在动物和植物奶油中的加标回收率分别为78.2%～117.1%、79.4%～114.6%，相对标准偏差分别为1.07%～12.1%、1.12%～12.5%；塑料接触材料中BPA和4-NP在奶油中的迁移量随着温度的升高和时间的延长逐渐增大。采用本方法对市售塑料蛋糕装饰摆件等在动物奶油中的迁移量等进行测定，迁出化合物BPA和双酚S迁移量最高值分别为4.61、0.94 μg/kg；4-NP迁移量最高值为125.1 μg/kg，检出样品数量最多。酚类化合物迁移到食品中的风险性应引起关注。     

Molecularly Imprinted Nanosilica Solid-Phase Extraction for Bisphenol A in Fish Samples

This paper reports a method using molecularly imprinted nanosilica as the solid-phase extraction sorbent to extract bisphenol A (BPA) from fish samples. The selective extraction efficiency of BPA from its structure-analogous by molecularly imprinted solid-phase extraction (MISPE) was compared with commercial C18 SPE column. The reproducibility of MISPE and optimal flow rate of sample were studied. There was a linear correlation in the concentration range of 0.7–114.1 μg l^?1 of BPA (r?=?0.997). The limit of detection (LOD) based on three times ratio of signal to noise was 0.11 μg l^?1. Under optimal conditions, the proposed method was applied to the analysis of BPA in fish samples. The amount of BPA in bream was 4.00 μg kg^?1, and both concentrations of BPA in crucian and weever were below the LOD. The recoveries of BPA standard solution spiked with fish samples were in the range of 92.56–102.3 % with the relative standard deviation less than 10 %.     

固相萃取-超高效液相色谱-串联质谱法测定饮用水中双酚A和双酚S

建立一种饮用水中痕量双酚A和双酚S的固相萃取-超高效液相色谱-串联质谱检测方法。水样中双酚A和双酚S经HLB固相萃取柱富集,甲醇洗脱并浓缩,再以1 mmol/L氟化铵-乙腈为流动相,经C18色谱柱分离,采用电喷雾离子源、质谱多反应监测模式分析。该方法对水样体积为500 mL时双酚A和双酚S检出限分别可达到1.0 ng/L和0.2 ng/L,在低、中、高3 个加标水平下两者的平均回收率分别为88.3%～114.8%和83.7%～98.2%,相对标准偏差分别为10.0%～16.2%和5.9%～12.3%。该方法灵敏度高、定性准确、操作简单高效,适用于饮用水中双酚A和双酚S的定性定量分析。     

Solid-phase extraction for selective determination of bisphenol A in drinks and fruits by dummy surface molecularly imprinted polymer with direct synthetic method

A reliable and selective method was developed for the determination of bisphenol A (BPA) in drinks and fruit using dummy surface molecularly imprinted polymer (DSMIP) as a solid-phase extraction (SPE)-enrichment and separation sorbent coupled with high-performance liquid chromatography (HPLC). Tetrabromobisphenol A (TBBPA), whose structure is similar to BPA, was selected as a dummy template molecule. DSMIP has a higher selectivity for BPA than surface non-imprinted polymer (SNIP) when used as sorbents for SPE. Potential factors affecting the extraction efficiency, including conditioning, sample loading, washing and elution, and the breakthrough volume were optimised. Under the optimum experimental conditions, the recoveries of BPA in drinks and fruit were in the range from 98% to 105% with relative standard deviations (RSDs) below 7%, and a limit of detection (LOD) of 3 ng ml^?1. The developed extraction protocol eliminated the effect of template leakage on quantitative analysis and could be applied to the trace determination of BPA in complicated functional samples.     

表面氨基化的Fe3O4/SiO2复合磁性纳米粒子提取白酒中羧酸的研究

利用化学共沉淀法制备磁性四氧化三铁纳米粒子,并用SiO2 和3- 氨丙基三乙氧基硅烷(APTES)依次对磁性纳米颗粒进行表面修饰,成功获得表面氨基改性后的磁性Fe3O4/SiO2 复合纳米粒子;采用红外光谱(IR)、透射电子显微镜(TEM)对氨基改性前后的Fe3O4/SiO2 复合纳米粒子的形态、结构进行表征。并利用- NH2 在常温下易与羧基反应的原理,用氨基改性后的磁性Fe3O4/SiO2 复合纳米粒子提取白酒中的羧酸类物质,用气相色谱- 质谱(GC-MS)联用对提取情况进行研究。结果表明：氨基改性后的磁性Fe3O4/SiO2 复合纳米粒子与白酒中的羧基能够发生较好的键合反应,从而实现提取白酒中羧酸的效果。     

肉类食品中磺胺类磁性纳米微粒的制备及其性能研究

Fe3O4磁性纳米粒子作为一种新型多功能材料,因其独特的磁学特性被广泛应用于材料及生物医学等领域。通过共沉淀法制备Fe3O4磁性纳米粒子,聚乙二醇(PEG)进行改性,通过计算机模拟Fe3O4晶体结构,红外光谱对样品进行分析,并进一步进行流变学、磁光性等性能研究。期望可以将磁纳米粒子与分子印迹技术相结合,制备出用于快速检测肉类食品中磺胺残留的新型磁性分子印迹材料。     

Determination of bisphenol A in milk and dairy products by high-performance liquid chromatography with fluorescence detection

This study was conducted to develop a selective and sensitive method for the determination of bisphenol A (BPA) levels in milk and dairy products. A method based on solvent extraction with acetonitrile and solid-phase extraction (SPE) was developed for the analysis of BPA in milk, yogurt, cream, butter, pudding, condensed milk, and flavored milk, and a method using two SPE cartridges (OASIS HLB and Florisil cartridge) for skim milk was also developed. The developed methods showed good recovery levels (77 to 102%) together with low detection limits (1 microg/liter for milk, yogurt, pudding, condensed milk, flavored milk, and skim milk and 3 microg/liter for cream and butter). These methods are simple, sensitive, and suitable for the analysis of BPA in milk and dairy products. When 40 milk and dairy products were analyzed by the proposed methods, BPA was not identified in noncanned products, but its levels ranged from 21 to 43 microg/kg in canned products, levels that were 60- to 140-fold lower than the migration limits in the European Union and Japan.     

Determination of Estrogens in Milk Samples by Magnetic‐Solid‐Phase Extraction Technique Coupled With High‐Performance Liquid Chromatography

A magnetic‐solid‐phase extraction method coupled with high‐performance liquid chromatography and diode array detection has been developed for simultaneous determination of 3 estrogens in milk samples. In this work, Fe₃O₄ NPs were synthesized by a simple chemical co‐precipitation reaction, and the surface of Fe₃O₄ was modified with cetyltrimethyl ammonium bromide (CTAB; designed as Fe₃O₄@CTAB). The synthesized Fe₃O₄@CTAB NPs were characterized by Fourier transformed infrared spectroscopy, scanning electron microscopy, and transmission electron microscope. Fe₃O₄@CTAB NPs have high binding affinity toward estrone (E1), 17β‐estradiol (17β‐E2), and diethylstilbestrol (DES). Fe₃O₄@CTAB NPs can be easily separated from sample solutions using an external magnet due to the high super‐paramagnetic property. The separation, preconcentration procedure is fast and will be completed in 2 min. Estrogens linear dynamic ranges were achieved in the range of 10 to 1000 ng/mL with regression coefficients (R²) higher than 0.9992. The limits of detection were between 0.26 and 0.61 ng/mL. Parameters influencing the recoveries were investigated and optimized. The proposed method was used for the determination of E1, 17β‐E2, and DES in milk samples, and recoveries were ranged from 91.3% to 105.0%, with the relative standard deviations in the range of 2.7% to 4.0%.     

Solid phase extraction of large volume of water and beverage samples to improve detection limits for GC-MS analysis of bisphenol A and four other bisphenols

Solid phase extraction (SPE) of large volumes of water and beverage products was investigated for the GC-MS analysis of bisphenol A (BPA), bisphenol AF (BPAF), bisphenol F (BPF), bisphenol E (BPE), and bisphenol B (BPB). While absolute recoveries of the method were improved for water and some beverage products (e.g. diet cola, iced tea), breakthrough may also have occurred during SPE of 200 mL of other beverages (e.g. BPF in cola). Improvements in method detection limits were observed with the analysis of large sample volumes for all bisphenols at ppt (pg/g) to sub-ppt levels. This improvement was found to be proportional to sample volumes for water and beverage products with less interferences and noise levels around the analytes. Matrix effects and interferences were observed during SPE of larger volumes (100 and 200 mL) of the beverage products, and affected the accurate analysis of BPF. This improved method was used to analyse bisphenols in various beverage samples, and only BPA was detected, with levels ranging from 0.022 to 0.030 ng/g for products in PET bottles, and 0.085 to 0.32 ng/g for products in cans.     

功能化磁性吸附材料制备及其在食品重金属检测中的应用

以Fe3O4作为载体,L-半胱氨酸(含巯基)作为功能单体,设计合成一种针对重金属吸附的L-半胱氨酸功能化Fe3O4磁性材料,并通过透射电镜及X射线光电子能谱等手段对材料进行表征。表征结果显示,磁性Fe3O4微球被硅胶层包裹在内,形貌上呈现典型"核-壳"结构,材料表面S元素负载量达8.2%(硫原子百分比)。以该材料作为固相萃取的吸附剂,吸附等温方程符合Langmuir吸附模型,Cd2+和Cu2+的最大吸附容量分别为238.1 mg/g和227.3 mg/g。结合石墨炉原子吸收光谱法,构建基于食品中痕量Cd2+和Cu2+的检测方法。系统考察影响吸附效率的多个参数,包括吸附选择性、吸附液pH值、吸附时间等。在优化条件下,该方法对Cd2+和Cu2+检测的线性范围均为:0.2μg/L^5.0μg/L,相关系数R2>0.997 0,检出限分别为0.12、0.13μg/L。将该方法用于实际样品的检测,回收率为87.0%~94.0%,相对标准偏差小于6.0%。     

Migration of plasticisers from Tritan™ and polycarbonate bottles and toxicological evaluation

This study is aimed to compare Tritan™ and polycarbonate (PC) from a point of view of migration of monomers and additives and toxicological evaluation. Migration assays were performed according with Commission Regulation (UE) No. 10/2011. Samples were incubated at 40 °C for three consecutive periods of 10 days. Identification and quantification of the compounds intended to migrate was done using solid phase extraction (SPE) followed by gas chromatography coupled to mass spectrometry (GC–MS) in scan mode. Compounds identified in Tritan™ were 2-phenoxyethanol (2-PE), 4-nonylphenol (4-NP), bisphenol A (BPA), benzylbuthyl phthalate (BBP) and dimethyl isophthalate (DMIP) at levels from 0.027 ± 0.002 to 0.961 ± 0.092 μg/kg, although in the 3rd migration period, BBP and DMIP were the only compounds detected well below the specific migration limit. On the other hand, BPA was the only compound detected in PC polymers at a mean concentration of 0.748 μg/kg. In vitro bioassays for (anti)estrogenic, (anti)androgenic as well as retinoic acid- and vitamin D-like activity were negative for Tritan™ and PC migrates. BPA and DMIP were estrogenic in high concentrations. Exposure of the estrogen-sensitive molluskan sentinel Potamopyrgus antipodarum confirmed the estrogenic activity of BPA in vivo at 30 μg/L.     

Fractionation and determination of aluminum and iron in soil water samples using SPE cartridges and ICP-AES

The use of commercially available solid phase extraction (SPE) cartridges for the fractionation of Al and Fe in soil water is described. The quantitative determination was done by inductively coupled plasma atomic emission spectrometry (ICP-AES). Different types of SPE cartridges, based on cation exchange, anion exchange, and chelation were studied. To avoid pH changes, the SPE cartridge should be conditioned with a buffer that has a pH close to that of the sample. Both strong cation exchange (SCX) and chelation were found to work well, whereas low recovery was observed for Al when anion exchange was used. For Fe, the sum of the anionic and cationic fractions that passed through the cartridges was nearly 100%. The results obtained for Al for 23 soil water samples using a SPE/SCX cartridge and ICP-AES were compared with equilibrium calculations using the program ALCHEMI and also with a fractionation method that was based on separation on a manually prepared SCX column and detection by molecular spectrophotometry, after complexation with pyrocatechol violet (SCX-PCV method). The SPE/SCX-ICP-AES results for the labile Al fraction (Al bound to the SCX cartridge) showed an acceptable correlation with the results obtained by the equilibrium calculations, except for the samples with the highest DOC concentrations, whereas the values obtained for labile Al by the more traditional SCX-PCV method were much lower. We recommend that the SPE/SCX-ICP-AES procedure described in this work be selected for the fractionation of Al and Fe species in soil and freshwater samples.     

粮食真菌DNA快速高通量提取方法的建立与应用

目的 建立一种高效、快速、高通量的粮食中真菌DNA提取和分析方法,并应用于小麦产脱氧雪腐镰刀菌烯醇(deoxynivalenol, DON)镰刀菌污染状况研究。方法 基于磁珠纯化技术,开发了一种粮食基质中真菌DNA的快速提取方法—月桂酰肌氨酸钠(sodium lauroyl sarcosine, SLS)磁珠法,结合前期采用实时荧光定量PCR法(quantitative real-time PCR, qPCR)和微滴式数字PCR法(droplet digital PCR, ddPCR)建立的小麦中3-乙酰基脱氧雪腐镰刀菌烯醇(3-acetyldeoxynivalenol, 3-ADON)和15-乙酰基脱氧雪腐镰刀菌烯醇(15-acetyldeoxynivalenol, 15-ADON)两种产DON毒素化学型镰刀菌及禾谷镰刀菌复合群分析方法,对其提取效果进行了验证并分析了我国2021年新收获小麦产DON镰刀菌的污染水平。结果 与十六烷基三甲基溴化铵(cetyl trimethyl ammonium bromide,CTAB)法、柱式法试剂盒和磁珠法试剂盒相比较,本研究建立的SLS磁珠法裂解过程无需水浴,配合自动化提取设备工作,整个提取时间小于1 h,对禾谷镰刀菌复合群的提取率最优,而对3-ADON和15-ADON化学型镰刀菌的提取率与经典CTAB法、磁珠法试剂盒没有显著性差异,并且显著性优于柱式法试剂盒。在对2021年收获的120个小麦样品监测结果显示,产DON镰刀菌的生物量与DON毒素水平之间具有极显著的相关性(P<0.01)。结论 SLS磁珠法适用于从基质复杂的粮食样品中提取真菌DNA,操作简便快速、提取率高,更易实现大样本量的分子生物学准确定量检测需求。     

双水相萃取大豆苯丙氨酸研究

采用十六烷基三甲基溴化铵(CTAB)和十二烷基硫酸钠(SDS)表面活性剂体系形成双水相,研究大豆蛋白水解液中L–苯丙氨酸分配及萃取效果。CTAB/SDS双水相体系萃取L–苯丙氨酸结果表明,当双水相体系CTAB与SDS摩尔比为0.256,提取液初始苯丙氨酸含量为0.02克,Na2SO4浓度为0.23mol/L时,萃取率最高可达96.9%。     

表面增强拉曼光谱法快速测定保健酒中西地那非

目的 建立金核银壳结构纳米颗粒(Au@Ag NPs)的表面增强拉曼光谱法(surface-enhanced Raman scattering, SERS)快速检测保健酒中非法添加物西地那非的分析方法。方法 制备3种纳米粒子Ag、Au、Au@Ag NPs为SERS基底, 比较3种基底的增强效果。样品前处理基于溶剂萃取法, 利用二氯甲烷对保健酒中的西地那非进行简单提取, 通过调节体系pH值, 得到最佳提取率和SERS增强效果。结果 Au@Ag NPs的SERS增强效应优于Au NPs和Ag NPs; 用0.1 mol/L氢氧化钾调节溶液pH值可有效提高二氯甲烷的提取效果, 再用0.1 mol/L稀盐酸溶解挥发后残留物, 使得西地那非在pH调节后更有利于吸附在Au@Ag NPs表面, 获得更强的SERS信号。西地那非的检出限为0.5 mg/L, 在0.5~10 mg/L浓度范围内线性关系较好, 相关系数(r2)为0.9472, 回收率为86.0%~95.8%之间, 相对标准偏差(relative standard deviation, RSD)为3.6%~5.9%。 结论 SERS技术灵敏度高、特异性强, 可用于快速检测保健酒中的西地那非, 为快速筛查大量样品提供新方法。