Novel approaches to analysis of 3-chloropropane-1,2-diol esters in vegetable oils

A sensitive and accurate method utilizing ultra-high performance liquid chromatography (U-HPLC) coupled to high resolution mass spectrometry based on orbitrap technology (orbitrapMS) for the analysis of nine 3-chloropropane-1,2-diol (3-MCPD) diesters in vegetable oils was developed. To remove the interfering triacylglycerols that induce strong matrix effects, a clean-up step on silica gel column was used. The quantitative analysis was performed with the use of deuterium-labeled internal standards. The lowest calibration levels estimated for the respective analytes ranged from 2 to 5 μg kg⁻¹. Good recovery values (89–120%) and repeatability (RSD 5–9%) was obtained at spiking levels of 2 and 10 mg kg⁻¹. As an alternative, a novel ambient desorption ionization technique, direct analysis in real time (DART), hyphenated with orbitrapMS, was employed for no separation, high-throughput, semi-quantitative screening of 3-MCPD diesters in samples obtained by chromatographic fractionation. Additionally, the levels of 3-MCPD diesters measured in real-life vegetable oil samples (palm oil, sunflower oil, rapeseed oil) using both methods are reported. Relatively good agreement of the data generated by U-HPLC-orbitrapMS and DART-orbitrapMS were observed. With regard to a low ionization yield achieved for 3-MCPD monoesters, the methods presented in this paper were not yet applicable for the analysis of these contaminants at the naturally occurring levels.     

Analysis of multiple mycotoxins in cereals under ambient conditions using direct analysis in real time (DART) ionization coupled to high resolution mass spectrometry

Direct analysis in real time (DART) ionization coupled to an (ultra)high resolution mass spectrometer based on orbitrap technology (orbitrapMS) was used for rapid quantitative analysis of multiple mycotoxins isolated from wheat and maize by modified QuEChERS procedure. After initial evaluation of ionization efficiencies for major groups of mycotoxins achievable with DART technology, sample preparation procedure and instrument parameter settings were optimized to obtain sensitive and accurate determination of most intensively ionizing toxins (deoxynivalenol, nivalenol, zearalenon, actyldeoxynivalenol, deepoxy-deoxynivalenol, fusarenon-X, altenuene, alternariol, alternariolmethylether, diacetoxyscirpenol, sterigmatocystin). The lowest calibration levels (LCLs) estimated for the respective analytes ranged from 50 to 150 μg kg⁻¹. Quantitative analysis was performed either with the use of matrix-matched standards or by employing commercially available ¹³C-labeled internal standards (available for deoxynivalenol, nivalenol and zearalenon). Good recoveries (100-108%) and repeatabilities (RSD 5.4-6.9%) were obtained at spiking level 500 μg kg⁻¹ with isotope dilution technique. Based on matrix-matched calibration, recoveries and repeatabilities were in the range 84-118% and 7.9-12.0% (RSD), respectively. The trueness of data obtained for deoxynivalenol and zearalenon in wheat/maize by DART-orbitrapMS was demonstrated by analysis of certified reference materials (CRMs). Good agreement of these results with data generated by validated ultra-high pressure liquid chromatography-time-of-flight mass spectrometry method was documented.     

Development and validation of a liquid chromatography/tandem mass spectrometric method for the determination of 39 mycotoxins in wheat and maize

This paper describes the first validated method for the determination of 39 mycotoxins in wheat and maize using a single extraction step followed by liquid chromatography with electrospray ionization triple quadrupole mass spectrometry (LC/ESI-MS/MS) without the need for any clean-up. The 39 analytes included A- and B-trichothecenes (including deoxynivalenol-3-glucoside), zearalenone and related derivatives, fumonisins, enniatins, ergot alkaloids, ochratoxins, aflatoxins and moniliformin. The large number and the chemical diversity of the analytes required the application of the positive as well as the negative ion ESI mode in two consecutive chromatographic runs of 21 min each. The solvent mixture acetonitrile/water/acetic acid 79 + 20 + 1 (v/v/v) has been determined as the best compromise for the extraction of the analytes from wheat and maize. Raw extracts were diluted 1 + 1 and were injected without any clean-up. Ion-suppression effects due to co-eluting matrix components were negligible in the case of wheat, whereas significant signal suppression for 12 analytes was observed in maize, causing purely proportional systematic errors. Method performance characteristics were determined after spiking blank samples on multiple levels in triplicate. Coefficients of variation of the overall process of <5.1% and <3.0% were obtained for wheat and maize, respectively, from linear calibration data. Limits of detection ranged from 0.03 to 220 microg/kg. Apparent recoveries (including both the recoveries of the extraction step and matrix effects) were within the range of 100 +/- 10% for approximately half of the analytes. In extreme cases the apparent recoveries dropped to about 20%, but this could be compensated for to a large extent by the application of matrix-matched standards to correct for matrix-induced signal suppression, as only a few analytes such as nivalenol and the fumonisins exhibited incomplete extraction. For deoxynivalenol and zearalenone, the trueness of the method was confirmed through the analysis of certified reference materials.     

高效液相色谱-线性离子阱/静电场轨道阱高分辨质谱法快速筛查和确证纺织品中禁用的偶氮染料

建立了高效液相色谱-线性离子阱/静电场轨道阱高分辨质谱(HPLC-LTQ/Orbitrap MS)快速筛查确证纺织品中禁用的偶氮染料的方法。样品在柠檬酸缓冲液中由连二亚硫酸钠还原成芳香胺,经硅藻土提取柱净化后,用Acquity UPLC BEH C18柱(50 mm×2.1 mm, 1.7 μm)分离,以甲醇和0.1%(v/v)甲酸作为流动相进行梯度洗脱,电喷雾正离子(ESI+)模式电离,高分辨质谱一级全扫描用于筛选分析,数据依赖扫描模式的二级碰撞诱导解离(CID)谱图用于确证,对纺织品样品中的偶氮染料进行定性鉴别。在0.05~2.00 mg/L范围内,21种致癌芳香胺的线性相关系数均大于0.99。通过实际样品的加标回收测定,回收率范围为65.5%~111.5%,相对标准偏差(n=6)为0.87%~2.49%。该方法的定量限可以达到0.08 mg/kg,可用于纺织品中禁用偶氮染料的实际检验工作。     

Development and Validation of a Dispersive Solid Phase Extraction Liquid Chromatography Mass Spectrometry Method with Electrospray Ionization for the Determination of Multiclass Pesticides and Metabolites in Meat and Milk

A dispersive solid phase extraction–liquid chromatography tandem mass spectrometry method with electrospray ionization was validated in food of animal origin for the determination of multiclass pesticide residues and their metabolites. A simple and low-cost sample preparation procedure using freezing as the clean-up step was used to identify and quantify analytes belonging to 39 different chemical classes in meat and milk matrices. Mean recoveries in the range of 70–120% with relative standard deviations <10% were obtained for the majority of the analytes. The limit of quantification of the method was 10 µg/kg. The matrix effects were statistically evaluated and the quantification of the analytes was conducted using calibration curves constructed with matrix matched calibration standards covering concentrations from 5 to 200 µg/kg. The proposed method was applied in 86 samples of animal origin taken from the Greek market, two of which were found positive for pesticides.     

超高效液相色谱-四极杆/静电场轨道阱高分辨质谱对粮谷产品中20种真菌毒素的快速筛查和确证

建立了超高效液相色谱-四极杆/静电场轨道阱高分辨质谱快速筛查和确证粮谷产品中20种真菌毒素的方法。样品经乙腈（含2%（体积分数）甲酸）提取,用Captiva EMR-Lipid小柱净化,采用Thermo Hypersil Gold C₁₈柱（100 mm×2.1 mm,1.9 μm）分离,用四极杆/静电场轨道阱高分辨质谱进行分析。在全扫描模式下以分析物的保留时间和一级母离子信息实现快速筛查,以自动触发采集的二级碎片离子信息进行确证。结果显示,目标分析物在各自的质量浓度范围内线性关系良好（相关系数r²>0.99）,方法检出限为0.25~20 μg/kg,回收率为72.9%~117.8%,相对标准偏差为2.9%~15.2%（n=6）。该方法灵敏度高,结果准确、可靠,适用于粮谷产品中20种真菌毒素的快速筛查和确证。     

Analytical method for the determination of mycotoxins in indoor/outdoor airborne particulate matter by HPLC-MS-MS

An effective analytical method for the screening of mycotoxins, in indoor/outdoor airborne particulate matter, was developed and method performance data are presented. Mycotoxins are natural compounds produced, in particular conditions, as secondary metabolites by filamentous fungi and moulds, and, after their production, they can be transported far from their source. To simulate real samples, an urban dust (reference material 1649a) free from mycotoxins was used as matrix and spiked by the most common mycotoxins, chosen on the basis of studies carried out previously in other real matrices: deoxynivalenol, aflatoxin B1, ochratoxin A, T-2 toxin, zearalenone and sterigmatocystin. The analytical method was optimised and structured in four successive steps: (1) accelerated solvent extraction of the (spiked) analytes from matrix, (2) solid-phase purification (SPE) of the previous extract, (3) pre-concentration of the eluates from SPE and (4) analysis of the concentrated eluates by high performance liquid chromatography tandem mass spectrometry in multiple reaction monitoring mode. After a proper sampling campaign, the method was applied to real indoor and outdoor particulate matter samples, where the clean-up step showed to be very effective and fundamental to avoid misleading analytical results.     

A liquid chromatography/tandem mass spectrometric multi-mycotoxin method for the quantification of 87 analytes and its application to semi-quantitative screening of moldy food samples

This paper describes the extension of a previously published method based on liquid chromatography/electrospray ionization tandem mass spectrometry (HPLC/ESI-MS/MS) from 39 to currently 87 analytes. Besides the mycotoxins for which regulated concentrations exist, the method now comprises not only almost all mycotoxins for which standards are commercially available, but also a number of other important metabolites produced by fungi involved in food spoilage. The method is based on a single extraction step using an acidified acetonitrile/water mixture followed by analysis of the diluted crude extract. Method performance characteristics were determined after spiking breadcrumbs as model matrix at multiple concentration levels. With very few exceptions, coefficients of variation of the whole procedure of <5% and repeatabilities at the highest spiking level of <7% were obtained. Limits of detection ranged between 0.02 and 225 μg kg⁻¹. The quantitative determination of ergopeptides was disturbed by epimerization due to the acidic conditions. From the remaining 77 analytes, the apparent recoveries of nine substances deviated significantly from the CEN target range of 70–110% due to incomplete extraction and/or matrix effects. In principle, the latter can be compensated for by the application of matrix-matched calibration. The developed method was applied to 18 moldy samples (including bread, fruits, vegetables, jam, cheese, chestnuts and red wine) from private households. This study revealed the great value of the described method: 37 different fungal metabolites were identified at concentrations of up to 33 mg kg⁻¹, and some of these have never been reported before in the context of moldy food products. Figure ESI (+) MS/MS chromatogram (total ion current of all MRMs) of a sample of moldy dark bread     

Development of sensitive and rapid analytical methodology for food analysis of 18 mycotoxins included in a total diet study

A rapid and sensitive method for the determination of 18 mycotoxins in 24 different food matrices has been developed and validated. With the exception of beverages and oil samples, a simple extraction with acetonitrile:water 80:20 (0.1% formic acid) was applied. Fruit juice, wine and beer samples were simply diluted with water containing 0.1% formic acid. Oil samples were partitioned with acetonitrile/hexane in order to remove fats. Analyses were made by ultra-high performance liquid chromatography (UHPLC) coupled to tandem mass spectrometry with triple quadrupole. Validation was carried out in all selected matrices using blank samples spiked at two analyte concentrations. Extraction recoveries between 70 and 120% and relative standard deviations lower than 20% were obtained for the wide majority of analyte–matrix combinations. Matrix-matched calibration was used for a correct quantification in order to compensate for matrix effects. Limits of quantification were lower than maximum permitted levels for every regulated mycotoxin–matrix combination. The acquisition of three SRM transitions per compound allowed the unequivocal confirmation of positive samples, supported by the accomplishment of ion intensity ratios and retention time when compared with reference standards. The developed methodology was applied to the analysis of 240 samples within a total diet study performed at Comunidad Valenciana (Spain). The most frequently found mycotoxins were deoxynivalenol, fumonisin B1, ochratoxin A and zearalenone at low μg kg⁻¹ levels, mainly in bread, breakfast cereals and beer.     

超高效液相色谱-四极杆/静电场轨道阱高分辨质谱法测定焙烤食品及其原料中11种真菌毒素

建立了超高效液相色谱-四极杆/静电场轨道阱高分辨质谱(UPLC-HRMS)测定焙烤食品及其原料中11种真菌毒素的检测分析方法。样品经20 mL含1%(体积分数)甲酸的乙腈-水(9∶1,v/v)溶液提取,经2.0 g无水硫酸、0.5 g氯化钠和300 mg C18盐析、净化后进行检测。采用CORTECS C18色谱柱(100 mm×2.1 mm,1.6μm),以含0.1%(体积分数)甲酸的2 mmol/L乙酸铵溶液和含0.1%(体积分数)甲酸的2 mmol/L乙酸铵甲醇溶液为流动相进行梯度洗脱。结果显示,11种真菌毒素在各自的质量浓度范围内线性关系良好(相关系数r2≥0.996 0),方法的定量限为0.15~20.00μg/kg,样品加标回收率为64.38%~122.61%,相对标准偏差为1.52%~12.99%(n=6)。该方法简单快速、灵敏度高、结果准确、可靠,利用该方法可有效测定焙烤食品及其原料中常见真菌毒素的含量。     

Development of an economic ultrafast liquid chromatography with tandem mass spectrometry method for trace analysis of multiclass mycotoxins in Polygonum multiflorum

Rapid, economic, and highly effective determination of multiple mycotoxins in complex matrices has given huge challenges for the analytical method. In this study, an economic analytical strategy based on sensitive and rapid ultrafast liquid chromatography coupled to hybrid triple quadrupole/linear ion trap mass spectrometry technique was developed for the determination of seven mycotoxins of different chemical classes (aflatoxin B₁, B₂, G₁, and G₂, ochratoxin A, T‐2 toxin, and HT‐2 toxin) in Polygonum multiflorum. Target mycotoxins were completely extracted using a modified quick, easy, cheap effective, rugged, and safe method without additional clean‐up steps. The types of extraction solvents and adsorbents for the extraction procedure were optimized to achieve high recoveries and reduce coextractives in the final extracts. Due to significant matrix effects for all analytes (≤68.9% and ≥110.0%), matrix‐matched calibration curves were introduced for reliable quantification, exploring excellent linearity for the seven mycotoxins with coefficients of determination >0.9992. The method allowed high sensitivity with limit of detection in the range of 0.031–2.5 μg/kg and limit of quantitation in the range of 0.078–6.25 μg/kg, as well as satisfactory precision with relative standard deviations lower than 8%. Recovery rates were between 74.3 and 119.8% with relative standard deviations below 7.43%. The proposed method was successfully applied for 24 batches of P. multiflorum samples, and six samples were found to be positive with aflatoxin B₁, B₂, G₁, or ochratoxin A. The method with significant advantages, including minimum analytical time, low time and solvent consumption, and high sensitivity, would be a preferred candidate for economic analysis of multiclass mycotoxins in complex matrices.     

Identification and determination of mycotoxins and food additives in feed by HPLC–high-resolution time-of-flight mass spectrometry

High-resolution time-of-flight mass spectrometry combined with high performance liquid chromatography is proposed for the detection and determination of 25 mycotoxins and 8 food additives (coccidiostats) in animal feed, using simplified and rapid sample preparation. We developed a procedure for the identification and determination of analytes by the standard addition method. The lower limit of the analytical range is 1 (400) µg/kg for mycotoxins; the analytical range for coccidiostats in feed is 10–200 mg/kg. The relative standard deviation of the results does not exceed 10%. The analysis time is 0.5–1 h.     

A new approach to the effective preparation of plasma samples for rapid drug quantitation using on-line solid phase extraction mass spectrometry.

A procedure that permits rapid development of an optimized solid phase extraction (SPE) method for the analysis of drugs in plasma by on-line solid phase extraction-mass spectrometry (SPE-MS) has been developed. This procedure employs the concept of manipulating the pH and the percentage of organic solvent in the chromatographic mobile phase to affect the retention behaviors of both the matrix components and the analytes of interest. This resulted in the effective removal of matrix interferences from biological samples during SPE. During a the method development, only generic HPLC gradient approaches were needed, and multiple samples were pooled so that several SPE methods could be investigated at once. The analysis time per sample was 1.3 minutes. Thus, the time involved in the entire method development (analysis of a set of samples) was less than one hour. With the knowledge of the retention behaviors of the analytes with respect to the pH and the percentage of organic, it was then possible to compose an optimized SPE-MS method. This method consisted of a base/organic and then an acid/organic washing step, followed by a rapid gradient elution step. Due to the rigorous washing procedure, most matrix interferences were removed, and analytes eluted off the SPE sorbent suffered from very little matrix interference. Thus, quantitation of drugs in plasma by a single quadrupole mass spectrometer could be accomplished, something that was not possible when only a generic gradient was used for on-line SPE-MS. In addition, both external and internal calibration curves could be obtained for the concentration range from 5 to 500 ng/mL with correlation coefficients of 0.99 (using 1/x as a weighting factor) and relative standard deviations (RSDs) less than 10%. The results achieved were comparable to those obtained by the use of a triple quadrupole mass spectrometer. Moreover, the robustness of the method was tested by continuously injecting plasma samples. During 136 runs, the absolute peak area variation for these three basic drugs was less than 15% without taking the signal variation from the mass spectrometer into account. Significantly, the on-line developed method can be directly transferred to a 96-well format SPE plate.     

An LC-ESI-MS method for the quantitative analysis of bile acids composition in fecal materials

In this work, a liquid chromatography coupled with electrospray ionization mass spectrometry (LC-ESI-MS) method was developed and validated for quantification of bile acids in fecal materials. Co-eluting matrix impurities in fecal materials have been shown to greatly suppress the ionization of analytes in mass spectrometry, which is known as the matrix effect. To correct large quantitative errors caused by the matrix effect, we developed a scheme that combined the standard addition method with internal standard (SA-IS). The fecal sample pretreatment involved a single step of extraction with ethanol. Bile acids were separated using a Luna C(18) column (150 mm, 2 mm i.d., 5 μm) with gradient elution. The deprotonated analytes were detected in selective ion monitoring mode. Our results showed that, by using this method, the accuracy of quantification was significantly improved in comparison to the conventional internal standard method. The linearity, sensitivity, accuracy and precision of the method were within the range of 0.05-5 μmol/L. This SA-IS method was successfully applied to the analysis of bile acids in the samples collected from patients diagnosed with inflammatory bowel disease.     

LC–high resolution MS in environmental analysis: from target screening to the identification of unknowns

This article provides an overview of the state-of-the-art and future trends of the application of LC–high resolution mass spectrometry to the environmental analysis of polar micropollutants. Highly resolved and accurate hybrid tandem mass spectrometry such as quadrupole/time-of-flight and linear ion trap/orbitrap technology allows for a more reliable target analysis with reference standards, a screening for suspected analytes without reference standards, and a screening for unknowns. A reliable identification requires both high resolving power and high mass spectral accuracy to increase selectivity against the matrix background and for a correct molecular formula assignment to unknown compounds. For the identification and structure elucidation of unknown compounds within a reasonable time frame and with a reasonable soundness, advanced automated software solutions as well as improved prediction systems for theoretical fragmentation patterns, retention times, and ionization behavior are needed.     

超高效液相色谱-电喷雾串联四极杆质谱法检测牛奶中22种喹诺酮类抗菌素

应用液相色谱-电喷雾串联四极杆质谱仪,检测牛奶中的喹诺酮类(QNs)抗菌素.样品经柠檬酸磷酸盐缓冲液(Mcllvaine)超声提取,采用固相萃取(SPE)方法净化提取液并对目标物质进行富集,用UPLC-MS/MS检测.实验通过空白基质溶液稀释标准,建立校正的标准曲线,可以降低基质对离子化的干扰.结果表明:吡哌酸、依诺沙星、西诺沙星、奥索利酸在3～300 μg/kg,帕珠沙星在5～500 μg/kg,氧氟沙星、加替沙星、司帕沙星在0 5～50 μg/kg,其余14种喹诺酮类化合物在1～100 μg/kg的线性范围内均具有良好的线性关系,相关系数在0 9851～0 9997之间,定量限(LOQ)为0 008～0 339 μg/kg.除了氟甲喹、萘啶酸、那氟沙星的回收率小于60%外,其它喹诺酮的回收率均在63.1%～94.6%之间,相对标准偏差为0 86%～13.12%.     

Multi‐residue analysis of eight thioamphetamine designer drugs in human urine by liquid chromatography/tandem mass spectrometry

An analytical procedure for the simultaneous determination in human urine of several thioamphetamine designer drugs (2C‐T and ALEPH series) is reported. The quantitative analysis was performed by liquid chromatography/tandem mass spectrometry and has been fully validated. The mass spectrometer was operated in positive‐ion, selected reaction monitoring (SRM) mode. In order to minimize interferences with matrix components and to preconcentrate target analytes, solid‐phase extraction was introduced in the method as a clean‐up step. The entire method was validated for selectivity, linearity, precision and accuracy. The method turned out to be specific, sensitive, and reliable for the analysis of amphetamine derivatives in urine samples. The calibration curves were linear over the concentration range of 1 to 100 ng mL^?1 for all drugs with correlation coefficients that exceeded 0.996. The lower limits of detection (LODs) and quantification (LOQs) ranged from 1.2 to 4.9 ng mL^?1 and from 3.2 to 9.6 ng mL^?1, respectively. Copyright © 2009 John Wiley & Sons, Ltd.     

液相色谱-串联质谱法同时测定动物血浆中21种霉菌毒素或其代谢物残留

建立了同时检测动物血浆中黄曲霉毒素B1等21种霉菌毒素或其代谢物残留的液相色谱-串联质谱方法.动物血浆样品中加入0.1％甲酸-乙腈溶液、NaCl和无水MgSO4进行萃取,无水MgSO4和C18,PSA,A-AL对提取液进行脱水净化,经浓缩、复溶和离心后,再进行测定.采用反相C18色谱柱分离,以0.1％甲酸-0.5 mmol/L乙酸铵溶液和0.1％甲酸-甲醇溶液作为流动相进行梯度洗脱,采用电喷雾离子源(ESI)多反应监测离子模式(MRM)进行检测,基质标准曲线外标法进行定量分析,线性范围在0.05 ～ 100 ng/mL之间,方法的定量限为0.05 ～0.5 ng/mL.在高、中、低3个添加浓度水平下,21种霉菌毒素的平均回收率为62.0％ ～ 116.4％,相对标准偏差小于19％.     

Quantitative determination of alpha-cyclodextrin in human plasma by liquid chromatography/positive ion electrospray mass spectrometry

A sensitive and selective method for the determination of alpha-cyclodextrin in human plasma is described using beta-cyclodextrin as an internal standard. After protein precipitation with perchloric acid, the analytes were isolated from human plasma by solid-phase extraction on Bond Elut C18 cartridges. The compounds were chromatographed on a narrow-bore aminopropyl column (125 x 2 mm i.d., 5 microm) and analyzed by electrospray ionization mass spectrometry in the positive selected-ion mode using the [M+NH4]+ ion. The lower limit of quantitation was 5 ng ml(-1) of human plasma. Linear calibration curves were obtained over the concentration range 5-1000 ng ml(-1) of human plasma. The intra- and inter-assay precisions were <18% and the accuracy was <10.5% over the entire concentration range. During the method development, the ionization efficiencies of the analytes in plasma samples originating from different sources were examined to overcome the matrix effect problems caused by co-eluting endogenous compounds. The method was successfully applied to pharmacokinetic studies in human volunteers.     

Determination of ochratoxin A and T-2 toxin in alcoholic beverages by hollow fiber liquid phase microextraction and ultra high-pressure liquid chromatography coupled to tandem mass spectrometry

A new method for the determination of ochratoxin A and T-2 toxin in alcoholic beverages (wine and beer) by hollow fiber liquid microextraction was optimized. The extraction step was followed by ultra high-pressure liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS). The extraction procedure was based on the extraction of mycotoxins from the sample to the organic solvent (1-octanol) immobilized in the fiber, and afterwards, they were desorbed in a mixture of acetonitrile/water (80:20, v/v) at pH 7 prior to chromatographic determination. Different variables affecting the extraction process such as organic solvent, salt content, extraction time and desorption solution were studied. The developed method was validated in wine and beer, using white wine and alcoholic beer as representative matrices for both types of samples. Relative recoveries higher than 70% were obtained for the selected mycotoxins. Good linearity (R² > 0.993) was obtained and quantification limits (0.02-0.09 μg L⁻¹) below European regulatory levels were achieved. Repeatability, expressed as relative standard deviation, was always lower than 12%, whereas interday precision was lower than 21%. The proposed method was applied to the analysis of several types of wines and beers and ochratoxin A was detected in a rosé wine at 1.1 μg L⁻¹.