固相萃取-HPLC法测定浓缩梨汁中噻菌灵、多菌灵的残留量

研究了一种可同时测定浓缩梨汁中噻菌灵和多菌灵残留量的固相萃取-高效液相色谱分析方法.浓缩梨汁样品与水按一定比例稀释后,经过调pH、离心、过滤,用混合相固相萃取小柱(Mixed-mode SPE)进行提取、净化,用配有二级管阵列检测器(DAD)的液相色谱仪检测,外标法定量.使用噻菌灵和多菌灵对照品进行添加回收率测定,结果显示本方法对噻菌灵的最低检出限为0.020 mg/kg,回收率为80.5%~84.3%;对多菌灵的最低检出限为0.020 mg/kg,回收率为83.2%~92.5%;测定的相对标准偏差均不大于5%.本方法简单、快速、准确,能满足常规噻菌灵和多菌灵残留量检测的需要.     

固相萃取-高效液相色谱法同时测定噻菌灵和多菌灵在浓缩菠萝汁中的残留量

建立了一种可同时测定浓缩菠萝汁中噻菌灵和多菌灵残留量的反相高效液相色谱分析法。浓缩菠萝汁样品与水按一定比例稀释后,经过调节溶液的pH值、离心、过滤,用混合相固相萃取小柱(Mixed-mode SPE)进行提取、净化,并用配有二极管阵列检测器(DAD)的液相色谱仪检测,外标法定量。使用噻菌灵和多菌灵对照品进行添加回收率测定,结果显示,本方法对噻菌灵的检出限为0.020 mg/kg,回收率为75.7%~93.3%;对多菌灵的检出限为0.020 mg/kg,回收率为80.8%~99.2%;测定的相对标准偏差均不大于5.7%。本方法简单、快速、准确,能满足常规噻菌灵和多菌灵残留量检测的需要。     

超高效液相色谱-串联质谱法快速测定浓缩果汁中噻菌灵和多菌灵的残留量

建立了同时测定浓缩果汁中噻菌灵和多菌灵残留的超高效液相色谱-串联质谱快速检测法。样品用乙酸乙酯提取,以ACQUITY UPLC BEH C18色谱柱(50 mm×2.1 mm, 1.7 μm)进行超高效液相色谱分离,以电喷雾电离串联质谱正离子多反应监测(MRM)模式进行测定,以基质匹配标准溶液外标法定量。结果表明:在试验条件下,噻菌灵和多菌灵在0.5~10 μg/kg范围内线性关系良好,相关系数大于0.99,不同基质中的检出限(S/N=3)范围为0.12~0.23 μg/kg。在0.5、1.0和5.0 μg/kg 3个水平下噻菌灵和多菌灵的加标回收率为76.98%~108.7%,相对标准偏差(RSD)为2.95%~9.99%。同时,本研究对浓缩果汁中噻菌灵和多菌灵残留检测的基质效应进行了考察。本方法具有操作简便、快速、准确的特点,可用于浓缩果汁中噻菌灵和多菌灵残留量的日常检测。     

浓缩刺梨汁中噻菌灵和多菌灵残留量的高效液相色谱法测定

研究了一种可同时测定浓缩刺梨汁中噻菌灵和多菌灵残留量的固相萃取-高效液相色谱法。浓缩刺梨汁样品与水按一定比例稀释后，经过调pH、离心、过滤，用混合相固相萃取小柱（Mixed—mode SPE）进行提取、净化，用配有二级管阵列检测器（DAD）的液相色谱仪检测，外标法定量。用噻菌灵和多菌灵对照品进行添加回收率测定，结果显示本方法对噻菌灵的测定低限为0．020mg／kg，回收率为77．5％～87．1％；对多菌灵的测定低限为0．020mg／kg，回收率为74．0％～96．3％；测定的相对标准偏差均不大于7．4％。本方法能满足常规噻菌灵和多菌灵残留量检测的需要。     

固相萃取-高效液相色谱法测定饮料中多菌灵和噻菌灵

本研究采用HiCapt CT固相萃取(SPE)柱对食品中的多菌灵和噻菌灵进行富集净化,建立了高效液相色谱-紫外检测法测定饮料中的农药多菌灵和噻菌灵残留的分析方法。多菌灵和噻菌灵的检出限分别为0.23μg/L、0.22μg/L,定量限分别为0.74μg/L、0.70μg/L,回收率分别为81.74%~87.45%、87.26%~94.22%。该方法日内和日间相对标准偏差(RSD)分别小于7.5%和8.7%。所建立的方法可以有效除去果汁中的基质干扰,同时具备简单、快速、灵敏的优点,可用于果汁中多菌灵和噻菌灵的检测。     

苹果中多菌灵、噻菌灵和甲基托布津的高效液相色谱法分析

建立了同时检测苹果中多菌灵、噻菌灵和甲基托布津残留量的高效液相色谱(HPLC)分析方法.样品经乙酸乙酯提取,旋转蒸发仪浓缩,氮气吹干甲醇定容后,采用配有二极管阵列检测器(DAD)的HPLC测定,外标法定量.在添加不同浓度的标准品时,多菌灵、噻菌灵和甲基托布津的添加回收率分别为87.7%～118.7%、72.8%～80.3%、64.0%～66.8%.方法对多菌灵、噻菌灵和甲基托布津3种农药的检出限较低,分别为0.134、0.230和0.250mg/L,可以满足苹果汁中多菌灵、噻菌灵和甲基托布津的残留限量检测要求.检测果皮样品中的农药残留量,多菌灵的残留量为7.24×10-2mg/kg,噻菌灵和甲基托布津未检出,低于国标中规定的残留限量标准.     

分散微固相萃取-超高效液相色谱-高分辨质谱法测定葡萄酒和啤酒中多菌灵和噻菌灵

基于强阳离子交换填料（PCX）,采用分散微固相萃取前处理技术,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,建立了一种快速测定葡萄酒和啤酒中多菌灵和噻菌灵的方法。通过对分散微固相萃取技术中PCX用量、洗脱溶剂中氨水的体积分数、乙腈的体积分数和洗脱体积的优化,实现了样品中多菌灵和噻菌灵的有效净化。经BEH C₁₈（50 mm×2.1 mm,1.7 μm）色谱柱分离后,通过静电场轨道阱质谱靶向单一离子监测（targeted single ion monitoring,tSIM）结合数据依赖的二级质谱扫描（data dependent tandem mass spectrometry,ddMS²）采集模式进行定性定量分析。待测物多菌灵和噻菌灵在一定浓度范围内均呈良好线性关系,相关系数R²≥0.9999。在葡萄酒和啤酒基质中,多菌灵和噻菌灵的检出限分别为0.02和0.01 μg/L,定量限分别为0.06和0.03 μg/L。在0.1、1.0、100 μg/L 3个添加水平下,多菌灵和噻菌灵的加标回收率分别为95.6%~110.2%和87.5%~102.8%,日内精密度（RSD_r）分别为1.8%~5.2%和1.3%~4.8%,日间精密度（RSD_R）分别为4.3%~8.7%和4.8%~9.4%。该方法快速、简便、灵敏,适用于葡萄酒和啤酒中多菌灵和噻菌灵的残留检测。     

高效液相色谱法测定柑橘中多菌灵、噻菌灵、甲基硫菌灵和硫菌灵残留量

应用高效液相色谱法测定了柑橘中多菌灵、噻菌灵、甲基硫菌灵和硫菌灵的残留量。样品用乙腈提取后,经氨基活性碳复合固相萃取小柱净化处理,以甲醇-水混合溶液为流动相梯度洗脱,经ZORBAX Extend-C18(150 mm×4.6 mm,5μm)色谱柱分离,在267 nm波长处,用紫外检测器检测。4种菌灵农药的质量浓度在0.1~10.0 mg.L-1范围与其峰面积呈线性关系,检出限(3S/N)均为0.05 mg.kg-1。方法对多菌灵、噻菌灵、甲基硫菌灵和硫菌灵的平均回收率在75.0%~98.7%之间,相对标准偏差(n=7)在3.2%~14.3%之间。     

固相萃取-离子交换色谱法测定浓缩苹果汁中残留的苯菌灵、多菌灵、噻菌灵

建立固相萃取-离子交换色谱法测定浓缩苹果汁中苯菌灵、多菌灵和噻菌灵的残留量。样品直接用水稀释后,于80 ℃下将苯菌灵完全转化为多菌灵,再经SCX固相萃取柱富集,采用LC-SCX离子交换色谱柱(25 cm×4.6 mm,5 μm)分离,二极管阵列检测器检测,以0.1 mol/L KH2PO4溶液(pH 2.5)-乙腈(体积比为70 ∶30)为流动相,在1.0 mL/min下等度洗脱,于282 nm波长下检测。在0.02～2.0 mg/L范围内,多菌灵和噻菌灵的峰面积与其浓度呈良好的线性关系,最低检出限均可达到0.004 mg/kg,回收率为94.2%～100.4%,相对标准偏差低于4.2%。该方法简便、快速、灵敏、准确,可用于浓缩苹果汁中苯菌灵、多菌灵和噻菌灵残留量的检测。     

HPLC法同时测定苹果及浓缩苹果汁中吡虫清等4种农药的残留量

建立了反相高效液相色谱-双波长检测法同时测定苹果及浓缩苹果汁中多菌灵、噻菌灵、吡虫啉、吡虫清4种农药残留量的方法。苹果样品经乙腈提取,加水稀释,而浓缩苹果汁样品直接用体积分数20%乙腈稀释后,利用CH2Cl2液-液萃取净化。分析时用C18色谱柱分离,以乙腈-0.05%冰乙酸系统梯度洗脱,选择246 nm和280 nm双波长检测。该方法4种农药的线性关系良好(r≥0.9999),检出限均为0.002 mg/kg,加标回收率在84.3%~109.1%范围内,相对标准偏差为2.0%~5.4%。本方法能够满足农药残留检测要求。     

高效液相色谱法测定香蕉中的多菌灵、噻菌灵、甲基硫菌灵

采用高效液相色谱法测定香蕉中的多菌灵、噻菌灵、甲基硫菌灵。样品经乙腈提取、硅胶柱净化后用HPLC法测定,外标法定量。对样品前处理和色谱分析条件进行了研究和优化。3种杀菌剂在确定的浓度范围内线性良好,相关系数r≥0．999。添加3个浓度水平标准品的回收率分别为：多菌灵80．5％～91．2％,噻菌灵81．2％～86．9％．68．9％～72．6％。该法对多菌灵、噻菌灵、甲基硫菌灵3种杀菌剂的检出限较低,分别为0．008,0．009,0．015mg／kg。该方法可满足香蕉中多菌灵、噻菌灵、甲基硫菌灵的残留限量检测要求。     

Application of a mixed-mode solid-phase extraction and cleanup procedure for LC/MS determination of thiabendazole and carbendazim in apple juice

Recently, a mixed-mode solid-phase extraction (SPE) procedure was developed for rapid extraction and cleanup for determination of the fungicides thiabendazole and carbendazim in various fruit juices. This paper reports the application of that sample preparation procedure to the liquid chromatographic/mass spectrometric determination of these fungicides in apple juice with detection by positive electrospray ionization mass spectrometry (ESI/MS). Response was linear for sample concentrations from 2 to 500 microg/L (ppb). Recoveries averaged 74% (9% RSD) for carbendazim and 93% (9% RSD) for thiabendazole. After SPE cleanup, no matrix supression was observed for the ESI+ response for either compound studied. The method was applied to the analysis of incurred residues in 4 store-bought apple juices; carbendazim levels ranged from 10 to 70 microg/L and thiabendazole levels ranged from less than 2 to 130 microg/L.     

Determination of carbendazim,thiabendazole, and<Emphasis Type="Italic"> o-</Emphasis>phenylphenol residues in lemons by HPLC following sample clean-up by ion-pairing

An efficient analytical method is presented involving effective sample clean-up with solid-phase extraction and HPLC-UV analysis for the simultaneous determination of carbendazim, thiabendazole, and o-phenylphenol residues in lemons. Sample preparation involves extraction with acetonitrile acidified with trifluoroacetic acid and an ethyl acetate/petroleum ether mixture. Purification of the crude extract was carried out with liquid–liquid partitioning after addition of an aqueous ammonia solution. Final clean-up was performed on polymeric reversed-phase cartridges pretreated with sodium dodecyl sulfate. Chromatographic analysis was performed on a reversed-phase HPLC column isocratically eluted with an acetonitrile/water/ammonia mixture and UV detection at 254 nm. The chromatographic method is repeatable, reproducible, and sensitive. Fungicide recoveries from lemon samples fortified at levels of 5 and 1 mg kg^–1 were 81–85% for carbendazim, 96–98% for thiabendazole, and 81–106% for o-phenylphenol with coefficients of variation of 2.5–7.4%. Detection limits for carbendazim, thiabendazole, and o-phenylphenol in lemons were 0.21, 0.27, and 0.51 mg kg^–1, respectively.     

1,3,5‐Triethynylbenzene and melamine as monomers to synthesize three‐dimensional network porous aromatic frameworks based silica/florisil for determination of carbendazim and thiabendazole in spinach

In this study, the new and efficient three‐dimensional network porous aromatic frameworks materials called Silica‐PAFs‐a, Florisil‐PAFs‐a, Silica‐PAFs‐b, and Florisil‐PAFs‐b were first synthesized. The properties of materials were analyzed by five characterization methods. The materials were used as adsorbents in pipette‐tip solid‐phase extraction for the effective determination of carbendazim and thiabendazole in spinach sample. Meanwhile, the obtained materials were tested by static adsorption and dynamic adsorption. The result showed that the specific surface area of materials greatly increased after introducing three‐dimensional network porous aromatic frameworks. Microstructural modification exposed a large number of amino reactive groups that made them have a better adsorption amount for the two targets. The calibration graphs of carbendazim and thiabendazole in methanol were linear over 0.10–300.0 µg/mL, and the limits of detection and quantification were 0.00546 and 0.0182 µg/mL, and 0.00741 and 0.0247µg/mL respectively. A reliable analytical method was developed for recognition targets in spinach sample by Silica‐PAFs‐b with satisfactory extraction recoveries (96.25 and 100.51%). The proposed method using the material was applied for trace analysis of the carbendazim and thiabendazole residue.     

Trace determination of carbendazim, fuberidazole and thiabendazole in water by application of multivariate calibration to cross-sections of three-dimensional excitation-emission matrix fluorescence

The simultaneous determination of carbendazim, fuberidazole and thiabendazole was accomplished by cross-section (CS) fluorimetry in combination with multivariate calibration algorithms. The total luminescence information of the compounds was used to optimise the linear trajectories of the CS. A comparison between principal component regression (PCR) and two partial least squares (PLS) algorithms, PLS-1 and PLS-2, with different pre-processing methodologies was made. The final model, which applied the PLS-1 method, built using pesticide standard and emission spectra, was successfully used for the determination of these compounds in synthetic mixtures. However, a different PLS-1 multivariate calibration model, based on CS through the total luminescence spectroscopic data, was necessary for determining the cited pesticides in water samples. Mean centring was the best pre-processing technique in both PLS-1 models. This later calibration model was built from ultra-pure water samples spiked with known carbendazim, fuberidazole and thiabendazole concentrations, after solid-phase extraction (SPE). The method, which had a precision better than 5%, was shown to be suitable for carbendazim, fuberidazole and thiabendazole monitoring in water samples at trace levels.     

Analyses of pesticide residues in fruit-based baby food by liquid chromatography/electrospray ionization time-of-flight mass spectrometry

A liquid chromatography/electrospray ionization time-of-flight mass spectrometry (LC/ESI-TOFMS) method has been developed for the determination of 12 pesticides (namely, carbendazim, thiabendazole, imazalil, tridemorph, triadimefon, bitertanol, prochloraz, flutriafol, myclobutanil, iprodione, diphenylamine and procymidone) in fruit-based baby food (multi-fruit jars and juices intended for infant consumption). The developed method consists of a sample treatment step based on liquid-liquid extraction using acetonitrile, followed by a clean-up step based on dispersive solid-phase extraction (SPE) with a primary-secondary amine (PSA). Multi-fruit and apple juices were processed by a SPE procedure using Oasis HLB cartridges. Subsequent identification and quantitation was accomplished by LC/ESI-TOFMS analysis: the confirmation of the target pesticides was based on accurate mass measurements of selected ions (protonated molecules ([M+H]+) and fragment ions). Confirmation studies were accomplished at low concentration levels (10 microg kg-1) and accuracy errors lower than 2 ppm were obtained in most cases. Baby food extracts spiked at 10 microg kg-1 fortification level yielded average recoveries in the range 78-105% with relative standard deviations less than 10% for most of the analytes. Limits of detection (LODs) were between 0.1 and 4 microg kg-1 depending on the pesticide studied. Finally, the proposed method was applied to a total of 33 baby food samples from Spain and the United Kingdom. Although imazalil, thiabendazole and carbendazim were detected in a high number--over 60%- of baby food samples, none of the samples tested were found to be above the 0.01 mg kg-1 EU standard.