固相萃取-高效液相色谱联用检测饮用水中的磺酰脲类除草剂

本研究基于固相萃取-高效液相色谱联用技术,建立了同时检测饮用水中两种磺酰脲类除草剂-苯磺隆、氯磺隆农药残留的方法。用甲基丙烯酸、乙二醇二甲基丙烯酸酯、偶氮二异丁腈分别作为功能单体、交联剂和引发剂,合成新型的高选择性材料,并将此吸附材料用做固相萃取的吸附剂。同时对洗脱剂的种类、体积以及样品的pH进行了优化。结果表明,在0.1 mg/L~5 mg/L的范围内两种物质线性关系良好,最低检出限分别为0.74μg/L和0.81μg/L,7次重复实验精密度分别为1.30%和2.10%。最佳的洗脱条件下,在饮用水中加标三个不同的浓度(10μg/L、15μg/L、20μg/L)的苯磺隆和氯磺隆混合物,经固相萃取后测得两种目标物的回收率可达到70.14~80.24%和76.52~106.03%。结果表明该方法可以用于饮用水中磺酰脲类除草剂的定量研究。     

食品中磺酰脲类除草剂的高效液相色谱分析

建立一种同时测定磺酰类除草剂的高效液相色谱法(high performance liquid chromatography,HPLC)方法,以利于对农产品质量进行准确定量与有效监管。7种磺酰脲类除草剂(甲磺隆、氯磺隆、苄嘧磺隆、苯磺隆、吡嘧磺隆、甲磺胺磺隆和丙苯磺隆)经甲醇提取,C18固相萃取小柱萃取净化后,高效液相色谱测定,用C18色谱柱分离,以乙腈-甲醇-盐酸为流动相,梯度洗脱,紫外检测器在波长为220、230、240 nm处测定。方法的线性范围为0.5μg/mL^100.0μg/mL,检出限为0.011μg/mL^0.025μg/mL,标准溶液测定的保留时间和峰面积的相对标准偏差分别为0.18%~0.89%和2.57%~5.57%。将所建立的方法用于大豆、玉米和大米样品的分析,标回收率在81.0%~116.1%。本法准确快速,20 min内可完成一次分析周期,适用于食品样品中磺酰脲类除草剂的快速测定。     

食品中磺酰脲类除草剂的高效液相色谱分析

以藜麦麸皮为主要原料,应用超临界CO_2萃取技术提取藜麦麸皮皂苷,并应用响应面法对提取工艺进行优化。结果表明,最佳工艺参数为超临界压力37 MPa,超临界温度60℃,萃取时间96 min,乙醇浓度74%,在此条件下,藜麦麸皮皂苷提取率为0.96%。影响藜麦麸皮皂苷提取率因素由大到小依次为超临界压力萃取时间超临界温度乙醇浓度。通过超临界技术提取藜麦麸皮皂苷对藜麦麸皮附加值提高有借鉴意义,为藜麦麸皮进一步开发新产品提供技术参考。     

Simultaneous Determination of Six Parabens in Foods by Matrix Liquid-Phase Dispersion Extraction Combined with High-Performance Liquid Chromatography

A novel microextraction method termed matrix liquid-phase dispersion extraction (MLPDE) was presented in this paper. This method was adopted for the extraction of preservatives including methylparaben, ethylparaben, propylparaben, butylparaben, isopropylparaben, and isobutylparaben from different solid food samples. The extracted analytes were subjected to high-performance liquid chromatography (HPLC) analysis immediately. In this method, the food sample (0.50 g) was added previously to a syringe and then rinsed with hot water (45 °C). Subsequently, 2 ml extraction solvent (methanol) was added into the syringe. After ultrasonic extraction, food sample was dispersed into the methanol phase and a cloudy suspension came into being. Under the pressure of the plunger, methanol carrying the target analytes passed through 0.45 μm membrane and 10.0 μl of the eluent was injected into HPLC system. The important parameters including temperature, pH and volume of water, extraction solvent and its volume, sodium chloride addition, sample weight, and ultrasonic time as well as matrix effect were investigated. Under the optimum conditions, recoveries of the studied preservatives ranged from 93.7 % to 107.9 %. The intra-day and inter-day precisions (relative standard deviations) were less than 5.16 % and 5.32 %, respectively. The linear ranges of the method were 0.947–400 mg/kg with the correlation coefficients of 0.9988 to 0.9999. The limits of detection were 0.285 to 1.122 mg/kg. MLPDE is a very simple, rapid, cheap, and efficient method for extraction of nonpolar organic compounds from solid food samples. The proposed method has been successfully applied to the separation and quantification of six parabens in different solid food samples.     

Molecularly Imprinted Solid-Phase Extraction Coupled with High-Performance Liquid Chromatography for the Determination of Trace Trichlorfon and Monocrotophos Residues in Fruits

In this study, a novel molecularly imprinted polymer (MIL@MIP) that could selectively recognize the trichlorfon and monocrotophos was synthesized using metal-organic framework MIL-101 as support material. The prepared MIL@MIP was characterized by Fourier transform infrared, thermogravimetric analysis, scanning electron microscope, static adsorption, kinetic adsorption, and competitive adsorption analyses. Using this material as sorbent, a new method of molecularly imprinted solid-phase extraction coupled with high performance liquid chromatography for simultaneous determination of trichlorfon and monocrotophos was established. Under optimal conditions, the limit of detection (LOD) of this method for trichlorfon and monocrotophos detection was 0.011 and 0.015 mg/kg, respectively. The relative standard deviation (RSD) for five replicates of 0.05 mg/L trichlorfon and monocrotophos mixed solutions was within the range of 1.8 to 3.7 %. Apple and pear samples spiked with the two kinds of organophosphate pesticides were extracted and determined by using this method with good recoveries ranging from 86.5 to 91.7 %. Moreover, this method was successfully applied for the detection of the two organophosphate pesticides in strawberry samples.     

固相分散萃取-液相色谱法测定奶酪中3种雌激素

建立了同时测定奶酪中炔雌醇、己烯雌酚和双烯雌酚三种雌激素的高效液相色谱分析方法。采用固相分散萃取技术处理样品,弗罗里硅土为分散剂、乙腈为萃取剂,经氮气流浓缩,反相色谱分离,紫外230 nm检测得出结果。3种激素回收率分别为89.16%,98.22%和83.22%,相对标准偏差2.98%,1.20%和2.75%,方法检出限分别为0.25,0.25和0.12μg/g。对市售奶酪进行了实际测定,三种雌激素均未检出。     

Determination of Major Isoflavones in Soy Drinks by Solid-Phase Micro Extraction Coupled to Liquid Chromatography

A simple method for determination of major isoflavones (daidzein, genestein, genistin) and equol, a daidzein metabolite, has been developed using solid-phase micro extraction coupled to liquid chromatography with diode array UV detection. All the aspects influencing adsorption (fibre coating, extraction time, temperature, pH and salt addition) and desorption of the analytes (desorption and injection time and minimize carryover) were carefully investigated. The limits of detection obtained using a polydimethylsiloxane /divinylbenzene fiber coating were in the range 4 (genistein) to 38 (genistin) nM. The method proved to be useful for determination of analytes in soy-based products. Daidzein, genistein, and genistin were found in all samples (three soy milks and two blended rice/soy beverages) at concentrations ranging from 0.8?±?0.2 (daidzein) to 180.4?±?12.1 (genistin) μM, while glycitein and equol were found in three and in one of the drinks at levels between 1.7?±?0.1 and 5.0?±?0.2 μM and at 2.7?±?0.2 μM, respectively. The procedure was used to define the binding constants of isoflavones with serum albumin bovine that were found from 2.5?×?10⁴ (daidzein) to 2.9?×?10⁵ (genistein) L mol^?1. The method proposed restricts the use of organic solvents and can be used widely in most laboratories with standard equipment. In addition, it is suitable for easily studying the isoflavone interaction with the main constituents in plants, e.g., proteins and lipids, to evaluate their bioavailability and to clarify the controversial question on benefits for or damage to human health resulting from soy intake.     

基于离子液体的基质固相分散萃取结合高效液相色谱法测定肌肉组织中的氟喹诺酮类抗生素

将基质固相分散、离子液体均相液-液微萃取和高效液相色谱法相结合,建立一种用于肌肉组织中依诺沙星、培氟沙星、诺氟沙星和恩诺沙星4种氟喹诺酮类药物的分析方法。首先以硅胶为分散剂,以200μL 1-己基-3-甲基咪唑四氟硼酸盐([C_6mim]BF_4)离子液体为萃取剂,p H 1.0水溶液为洗脱剂,采用基质固相分散法处理样品,目标分析物被转移至洗脱液中后,再以六氟磷酸铵为离子对试剂,采用均相液-液微萃取法分离、富集目标分析物于离子液体相中,最后通过高效液相色谱-二极管阵列检测器对目标物进行定量分析。结果表明,各化合物在线性范围内具有较好的线性关系(r0.997 4),检出限为2.9~8.6μg/kg,加标回收率在87.9%~105.3%之间,其相对标准偏差为2.2%~8.6%。本法操作简单,不使用有机溶剂,可广泛应用于动物肌肉组织中氟喹诺酮类抗生素的萃取与检测。     

多壁碳纳米管基质固相分散-高效液相色谱测定牛奶中6种四环素

以多壁碳纳米管为吸附材料,建立基质固相分散萃取高效液相色谱法测定牛奶中6种四环素。将多壁碳纳米管、EDTA、草酸和样品研磨混匀装柱,经含甲酸的甲醇洗脱后HPLC多波长紫外检测。6种四环素的检出限0.01～0.03μg/mL,回收率78.7%～105.2%,相对标准偏差小于12%。多壁碳纳米管基质固相分散萃取牛奶中四环素的回收率优于C18,可推广到食品等复杂样品中其他农兽药多残留分析。     

Graphene Oxide-Reinforced Hollow Fiber Solid-Phase Microextraction Coupled with High-Performance Liquid Chromatography for the Determination of Cephalosporins in Milk Samples

An effective and sensitive method to determine six cephalosporins (cefadroxil, cephapirin sodium, cefixime, cefuroxime sodium, cefoxitin sodium, and ceftiofur hydrochloride) in milk samples was developed using graphene oxide-reinforced hollow fiber solid-phase microextraction (GO-HF-SPME). After extraction, analytes were desorbed and analyzed using high-performance liquid chromatography-photodiode array detection (HPLC-PDA). The graphene oxide (GO) was dispersed in N,N-dimethyl formamide by ultrasonication and then immobilized into the pores of a hollow fiber (HF). Several factors of GO-HF-SPME experiment, such as the pH of the sample solution, type of organic desorption solvent, pH of the desorption solvent, extraction time, and desorption time, were optimized to achieve the highest extraction efficiency. Under the optimized extraction conditions, the method showed good linear ranges (0.05–10 μg/mL) with correlation coefficients higher than 0.9950, low limits of determination (LODs, 0.01–0.02 μg/mL), and good recoveries (71–108 %) at three different spiked levels. The results demonstrated that GO-HF-SPME would be a promising method for the enrichment of cephalosporins in dairy products.     

Rapid and Selective Determination of Trace Benzimidazole Fungicides in Fruit Juices by Magnetic Solid-Phase Extraction Coupled with High-Performance Liquid Chromatography-Fluorescence Detection

In this paper, a new method was established for the determination of benzimidazole fungicides in fruit juices by magnetic solid-phase extraction coupled with high-performance liquid chromatography-fluorescence detection. The extraction adsorbent was synthesized to form a core–shell Fe₃O₄@SiO₂ structure surface functionalized with benzenesulfonic acid. The negative charges of the benzenesulfonic acid groups can promote strong electrostatic interaction with positively charged analytes to exhibit efficient and selective extractive ability. After the extraction, the magnetic adsorbent can be rapidly isolated from the matrix by an external magnet. Main factors influencing the extraction efficiency including amount of adsorbent, solution pH, extraction time, and volume of desorption solution were studied and optimized. Under the optimal conditions, recoveries of the spiked samples ranged from 83 to 96 % with the relative standard deviations lower than 10 %. The limits of detection were 0.55 and 0.14 μg?kg^?1 for carbendazim and thiabendazole, respectively. The proposed method was successfully applied for selective and efficient determination of benzimidazole fungicides in various juice samples.     

Air-Agitated Cloud-Point Extraction Coupled with High-Performance Liquid Chromatography for Determination of Heterocyclic Aromatic Amines in Smoked Sausages

An air-agitated cloud-point extraction procedure (AACPE), which is a new generation of cloud-point extraction procedure, has been investigated for extraction and preconcentration of four heterocyclic amines (i.e., 2-Amino-3,4-dimethyl-3H-imidazo[4,5-f]quinoline (MeIQ), 2-Amino-3,4,8-trimethyl-3H-imidazo[4,5-f]quinoxaline (4,8-DiMeIQx), 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), and 1-methyl-9H-pyrido[3,4-B]indole (harmane)) prior to high-performance liquid chromatography (HPLC). In order to enhance the extraction efficiency, the mixture of the aqueous sample solution and extraction solvent (Triton X-114) was repeatedly aspirated and dispensed using a syringe. Various parameters affecting the extraction efficiency of the AACPE procedure, including type and amount of salt, concentration of Triton X-114, extraction time (or number of air agitations), and centrifugation time, were investigated. No temperature controller was necessary. Under the optimum extraction condition, the linearity was achieved between 0.005 and 1.00 mg kg^?1 with the correlation coefficient (R ²) > 0.999. The low limit of detections (LODs) ranged from 0.001 to 0.003 mg kg^?1 with high enrichment factor (EF) more than 80. Matrix-matched calibration has been used for analysis of the target analytes in real samples. The applicability of the developed procedure was successfully evaluated by the determination of the heterocyclic amines in smoked sausage samples.     

固相萃取柱净化-超高效液相色谱-串联质谱法快速测定液态乳中14 种真菌毒素

建立使用固相萃取柱净化液态乳中14 种真菌毒素（黄曲霉毒素B1、黄曲霉毒素B2、黄曲霉毒素G1、黄曲霉毒素G2、黄曲霉毒素M1、赭曲霉毒素A、橘霉素、T-2毒素、杂色曲霉素、伏马毒素B1、伏马毒素B2、玉米赤霉烯酮、脱氧雪腐镰刀菌烯醇、青霉酸）多残留的超高效液相色谱-串联质谱检测方法。样品经含0.1%甲酸-乙腈沉淀蛋白和提取,固相萃取柱Oasis PRiME HLB净化后,以0.1%甲酸溶液与乙腈为流动相,经ACQUITY UPLC HSS T3色谱柱（2.1?mm×100?mm,1.8?μm）分离,梯度洗脱,采用电喷雾-正离子多反应监测模式,外标法定量。结果表明：14?种真菌毒素的定量限（RSN≥10）为0.5～5?μg/kg,高、中、低3?个添加水平时,平均回收率为67.7%～112.7%,相对标准偏差为0.43%～7.28%。该方法的检测速度快,净化效果较好,基质干扰较少,灵敏度高,结果准确、可靠,可用于液态乳中真菌毒素的检测分析。     

高效液相色谱-荧光检测器测定蜂王浆中氟喹诺酮类药物残留的研究

本研究采用液液萃取进行样品前处理,用带荧光检测器的液相色谱仪检测蜂王浆中的5 种QNs,具有方法简单、快速、准确、试剂用量少、检测成本低的特点。方法检测限为氧氟沙星5μg/kg,恩诺沙星、环丙沙星、诺氟沙星2.5μg/kg,丹诺沙星1μg/kg,能够满足目前对蜂王浆中QNs 允许限量的检测要求。     

Determination of Diazinon Pesticide Residue in Tomato Fruit and Tomato Paste by Molecularly Imprinted Solid-Phase Extraction Coupled with Liquid Chromatography Analysis

Food Analytical Methods - In the present study, an optimized molecularly imprinted polymer (MIP) was prepared and evaluated as a selective sorbent in solid-phase extraction and analysis in tomato...     

固相萃取-超高效液相色谱荧光法测定植物油中苯并(a)芘

采用中性氧化铝小柱净化样品,建立固相萃取-超高效液相色谱荧光法测定植物油中苯并(a)芘的方法。样品以正己烷为提取剂,净化、蒸发浓缩后正己烷溶解,荧光检测器检测。流动相为乙腈-水(75:25,V/V),流速0.5mL/min,外标法定量。苯并(a)芘在0.10～50.0μg/L质量浓度范围内线性关系良好,相关系数R2为0.9998;在空白样品中添加3个水平的标准品,回收率在91.7%～97.5%之间,相对标准偏差均小于2%(n＝3);最低检出限为0.01μg/kg,定量限为0.03μg/kg。方法操作简便、分析时间短、稳定性好、选择性好、灵敏度高,为植物油中苯并(a)芘的测定提供参考。     

基质固相分散-液相色谱法测定柑桔中唑螨酯残留

为优化唑螨酯在柑桔中残留分析方法,采用基质固相分散萃取、HPLC检测,结果表明:柑桔样品中唑螨酯适于基质固相分散萃取,以氧化铝作为分散剂,乙酸乙酯为洗脱剂,淋出液过氧化铝柱净化后HPLC测定,最低检出浓度为0.0625mg/kg,当桔皮、桔肉样品中添加浓度为0.1～1.0mg/kg时,方法的回收率在81.9%～96.3%之间,相对标准偏差为3.73%～7.54%,满足残留分析的要求。     

Matrix Solid-Phase Dispersion Extraction and Capillary Electrophoresis Determination of Tetracycline Residues in Milk

A capillary zone electrophoresis method was proposed for simultaneous detection and quantification of three tetracycline antibiotics in commercial milk samples, i.e., tetracycline, oxytetracycline, and doxycycline. The influences of the electrolyte composition, pH, as well as temperature and applied voltage on separation were investigated. The optimal running buffer was 30 mM Na₂HPO₄ and 1 mM EDTA at pH 11.5, with 3 s hydrodynamic injection, 25 kV applied voltage, and UV detection at 268 nm. Matrix solid-phase dispersion procedure was used for sample pretreatment. Several solid support materials were investigated, and silica with bonded C₁₈ chains (C₁₈) was used as sorbent. Electrophoretic analysis was completed in less than 6 min, with LODs ranging from 0.0745 μg/mL for oxytetracycline to 0.0808 μg/mL for doxycycline. The recoveries obtained were between 93.4% and 102%.