Rapid and sensitive liquid chromatography with tandem mass spectrometry method for the simultaneous quantification of yonkenafil and its major metabolites in rat plasma

Yonkenafil is a promising drug for treatment of male erectile dysfunction. Previous studies showed that the piperazine‐N,N’‐deethylation metabolite, piperazine‐N‐deethylation metabolite, and piperazine‐N‐deethylation‐N,N’‐deethylation metabolite were the major metabolites of yonkenafil after extensive metabolism. We developed a sensitive and selective method for the simultaneous quantification of yonkenafil and its major metabolites using high‐throughput liquid chromatography with tandem mass spectrometry. Analytes and internal standard were extracted from a small quantity of plasma (50 μL) using liquid–liquid extraction with diethyl ether/dichloromethane (60:40, v/v), and the baseline separation was achieved on Zorbax SB‐C₁₈ column using ammonia/water/methanol (0.2:20:80, v/v/v) as the mobile phase. The assay was performed with an electrospray positive ionization mass spectrometry through the multiple‐reaction monitoring mode within 2 min. Calibration curve of the method was linear within the range of 1.00–1000 ng/mL for all the analytes with the intra‐ and interday precisions of 4.0–5.2 and 4.0–5.3% for yonkenafil, 3.1–4.9 and 3.1–5.2% for the piperazine‐N,N’‐deethylation metabolite, 4.8–6.8 and 4.8–7.3% for the piperazine‐N‐deethylation metabolite, and 2.9–6.1 and 5.4–6.3% for the piperazine‐N‐deethylation‐N,N’‐deethylation metabolite, respectively. The recoveries were above 90% with low matrix effects. The validated assay was successfully applied to support a preclinical pharmacokinetic study in six rats using a single oral dose of yonkenafil (8 mg/kg).     

Simultaneous determination of cyadox and its metabolites in plasma by high‐performance liquid chromatography tandem mass spectrometry

Cyadox is a novel antimicrobial growth‐promoter of the quinoxalines. For food safety and pharmacokinetic studies, a convenient, sensitive and reproducible LC‐ESI‐MS/MS method was developed for the simultaneous determination of cyadox and its major metabolites, quinoxaline‐2‐carboxylic acid, 1,4‐bisdesoxycyadox, cyadox‐1‐monoxide and cyadox‐4‐monoxide in chicken plasma. Plasma sample was subjected to a simple deproteinisation with acetonitrile. Analysis was performed on a C₁₈ column by detection with mass spectrometry in multiple reaction monitoring mode. A gradient elution program with 0.2% formic acid, methanol and acetonitrile was performed at a flow rate of 0.2 mL/min. The decision limits (CCαs) of five analytes in plasma ranged from 1.0 to 4.0 μg/L, and the detection capabilities (CCβs) were <10 μg/L. Acceptable precision and accuracy were obtained for concentrations over the standard curve range. The extraction recoveries of five analytes were between 87.4 and 93.9% in plasma at the spiked levels of 5 (10)–200 μg/L with the relative standard deviations <10% for each analyte. The developed method demonstrated a satisfactory applicability in real plasma samples.     

Ultra performance liquid chromatography-tandem mass spectrometry for the determination of 5-nitroimidazoles and their metabolites in egg

An ultra performance liquid chromatography (UPLC) coupled to tandem mass spectrometry (MS/MS) procedure was developed for the determination of five 5-nitroimidazoles (dimetridazole, ipronidazole, metronidazole, ronidazole and ternidazole) and three of their metabolites (1-methyl-2-hydroxymethyl-5-nitroimidazole, 1-(2-hydroxyethyl)-2-hydroxymethyl-5-nitroimidazole and 1-methyl-2-(2′-hydroxyisopropyl)-5-nitroimidazole) in egg matrices. Conditions for UPLC separation and electrospray ionization MS/MS in the positive ion mode were optimized. Samples were prepared by liquid-liquid extraction with buffered aqueous 2.5% trichloroacetic acid followed by solid-phase extraction on a Strata-X-C cartridge with reversed-phase and cation-exchange functionalities. The method’s performance was evaluated in accordance with Commission Decision 2002/657/EC, applying the alternative matrix-comprehensive in-house validation approach using specially designed InterVal software. The method was robust against different sample matrix and SPE cartridges, operator change, and changes in sample extract storage. Acceptable apparent recoveries (76 to 109%) were obtained for all analytes. The decision limits (CC_α) and detection capabilities (CC_α) were within the ranges of 0.19–2.62 and 0.26–4.29 μg kg⁻¹. For all compounds the calibration curve linearity was good with correlation coefficients greater than 0.99. Fifteen eggs and ten whole egg powder samples obtained commercially in Lithuania were analyzed by UPLC-MS/MS; none were found contaminated by 5-nitroimidazoles or their metabolites.     

Liquid chromatography tandem mass spectrometry for the simultaneous determination of mequindox and its metabolites in porcine tissues

A rapid liquid chromatography tandem mass spectrometric method was developed for the simultaneous determination of mequindox and its five metabolites (2-isoethanol mequindox, 2-isoethanol 1-desoxymequindox, 1-desoxymequindox, 1,4-bisdesoxymequindox, and 2-isoethanol bisdesoxymequindox) in porcine muscle, liver, and kidney, fulfilling confirmation criteria with two transitions for each compound with acceptable relative ion intensities. The method involved acid hydrolysis, purification by solid-phase extraction, and subsequent analysis with liquid chromatography tandem mass spectrometry using electrospray ionization operated in positive polarity with a total run time of 15 min. The decision limit values of five analytes in porcine tissues ranged from 0.6 to 2.9 μg/kg, and the detection capability values ranged from 1.2 to 5.7 μg/kg. The results of the inter-day study, which was performed by fortifying porcine muscle (2, 4, and 8 μg/kg), liver, and kidney (10, 20, and 40 μg/kg) samples on three separate days, showed that the accuracy of the method for the various analytes ranged between 75.3 and 107.2% with relative standard deviation less than 12% for each analyte.     

Analysis of amicarbazone and its two metabolites in grains and soybeans by liquid chromatography with tandem mass spectrometry

A sensitive, simple and reliable analytical method based on a modified quick, easy, cheap, effective, rugged, safe sample preparation and liquid chromatography with tandem mass spectrometry detection was developed for the simultaneous determination of amicarbazone and its two major metabolites desamino amicarbazone and isopropyl‐2‐hydroxy‐desamino amicarbazone residues in grains (rice, wheat, corn, buckwheat) and soybean. Several parameters, including liquid chromatography and tandem mass spectrometry conditions, extraction approaches and the adsorbents for clean‐up, which might influence the accuracy of the method, were extensively investigated. The established method was further validated by determining the linearity (R² > 0.99), fortified recovery (79–118%), precision (1–12%) and sensitivity (limit of quantification, 5 μg/kg for amicarbazone and desamino amicarbazone, and 10 μg/kg for isopropyl‐2‐hydroxy‐desamino amicarbazone). Finally, the established method was successfully applied to determine the residues of amicarbazone and its metabolites in 49 real samples of grain and soybean.     

Simultaneous determination of rabeprazole and its two active metabolites in human urine by liquid chromatography with tandem mass spectrometry and its application in a urinary excretion study

A simple and rapid liquid chromatography with tandem mass spectrometry method has been developed and validated for the determination of rabeprazole and its two active metabolites, rabeprazole thioether and desmethyl rabeprazole thioether, in human urine using donepezil as the internal standard. The sample preparation procedure involved a simple dilution of urine sample with methanol (1:3, v/v). The chromatographic separation was achieved on a Hedera ODS‐2 C₁₈ column using a mixture of methanol/10 mmol/L ammonium acetate solution (containing 0.05% formic acid; 55:45, v/v) as the mobile phase. The method was validated over the concentration ranges of 0.15–100 ng/mL for rabeprazole, 0.30–400 ng/mL for rabeprazole thioether, and 0.05–100 ng/mL for desmethyl rabeprazole thioether. The established method was highly sensitive with a lower limit of quantification of 0.15 ng/mL for rabeprazole, 0.30 ng/mL for rabeprazole thioether, and 0.05 ng/mL for desmethyl rabeprazole thioether. The intra‐ and interbatch precision was <4.5% for the low, medium, and high quality control samples of all the analytes. The recovery of the analytes was in the range 95.4–99.0%. The method was successfully applied to a urinary excretion profiles after intravenous infusion administration of 20 mg rabeprazole sodium in healthy volunteers.     

A new liquid chromatography-tandem mass spectrometry method for determination of parabens in human placental tissue samples

Endocrine disruptors are a group of organic compounds widely used, which are ubiquitous in the environment and in biological samples. The main effect of these compounds is associated with their ability to mimic or block the action of natural hormones in living organisms, including humans. Parabens (esters of p-hydroxybenzoic acid) belong to this group of compounds. In this work, we propose a new liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to asses the presence of parabens most commonly used in industrial applications (methyl-, ethyl-, propyl- and butyl-paraben) in samples of human placental tissue. The method involves the extraction of the analytes from the samples using ethyl acetate, followed by a clean-up step using centrifugation prior to their quantification by LC-MS/MS using an atmospheric pressure chemical ionization (APCI) interface in the negative mode. Deuterated bisphenol A (BPA-d₁₆) was used as surrogate. Found detection limits (LOD) ranged from 0.03 to 0.06 ng g⁻¹ and quantification limits (LOQ) from 0.1 to 0.2 ng g⁻¹, while inter- and intra-day variability was under 13.8%. The method was validated using standard addition calibration and a spike recovery assay. Recovery rates for spiked samples ranged from 82% to 108%. This method was satisfactorily applied for the determination of parabens in 50 placental tissue samples collected from women who live in the province of Granada (Spain).     

Determination of itopride in human plasma by liquid chromatography coupled to tandem mass spectrometric detection: application to a bioequivalence study

A simple method using a one-step liquid-liquid extraction (LLE) with butyl acetate followed by high-performance liquid chromatography (HPLC) with positive ion electrospray ionization tandem mass spectrometric (ESI-MS/MS) detection was developed for the determination of itopride in human plasma, using sulpiride as an internal standard (IS). Acquisition was performed in multiple reaction monitoring (MRM) mode, by monitoring the transitions: m/z 359.5 > 166.1 for itopride and m/z 342.3 > 111.6 for IS, respectively. Analytes were chromatographed on an YMC C₁₈ reverse-phase chromatographic column by isocratic elution with 1 mM ammonium acetate buffer-methanol (20: 80, v/v; pH 4.0 adjusted with acetic acid). Results were linear (r² = 0.9999) over the studied range (0.5-1000 ng mL⁻¹) with a total analysis time per run of 2 min for LC-MS/MS. The developed method was validated and successfully applied to bioequivalence studies of itopride hydrochloride in healthy male volunteers.     

Quantification of piperazine phosphate in human plasma by high-performance liquid chromatography-electrospray ionization tandem mass spectrometry employing precolumn derivatization with dansyl chloride

This paper describes a novel method that combines dansyl chloride (DNS-CL) derivatization with high-performance liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI/MS/MS) for the sensitive and selective determination of piperazine phosphate in human plasma. After addition of ondansetron hydrochloride as internal standard (IS), piperazine phosphate was derivatized and then extracted with ethyl acetate. After being evaporated and reconstituted, the sample was analyzed using LC-ESI/MS/MS. Separation was achieved using an Agilent ZORBAX SB-C₁₈ (150 mm × 2.1 mm I.D., 3.5 μm) column and isocratic elution with 10 mM ammonium acetate solution (pH 3.0)-methanol (50: 50, v/v). Detection was performed on a triple-quadrupole mass spectrometer utilizing electrospray ionization (ESI) interface operating in positive ion and selected reaction monitoring (SRM) mode with the precursor to product ion transitions m/z 320 → 171 for DNS-CL-piperazine phosphate and m/z 294 → 170 for the IS. The method was fully validated for its selectivity, sensitivity, linearity, precision, accuracy, recovery, matrix effect and stability. The coefficient (r) of piperazine phosphate with a linear range of 0.1-15 μg mL⁻¹ was 0.9974-0.9995. The limit of detection and lower limit of quantification in human plasma were 0.01 and 0.1 μg mL⁻¹, respectively. The validated LC-ESI/MS/MS method has been successfully applied to a bioequivalence study of piperazine phosphate trochiscus in Chinese healthy male volunteers.     

Simultaneous determination of a new phosphodiesterase-5 inhibitor DA-8159 and its active metabolite in human plasma by high performance liquid chromatography with tandem mass spectrometry

Summary An LC-MS-MS method for the simultaneous determination of DA-8159 and its active metabolite, DA-8164 in human plasma was developed. DA-8159, DA-8164 and the internal standard, sildenafil were extracted from human plasma with dichloromethane at basic pH. A reversephase HPLC separation was performed on Luna phenylhexyl column with the mixture of acetonitrile-ammonium formate (10 mM, pH 6.0) (60:40,v/v) as mobile phase. The detection of analytes was performed using an electrospray ionization tandem mass spectrometry in the multiple reaction monitoring mode. The method showed a satisfactory sensitivity (lower limits of quantification, 2.0 ng mL¹), precision, accuracy, recovery and selectivity. The successful determination of DA-8159 and DA-8164 in the plasma of a volunteer who ingested a single dose of 100 mg DA-8159 confirms that the present method can be used for plasma analysis for clinical trial.     

Rapid confirmatory method for the determination of 11 nitroimidazoles in egg using liquid chromatography tandem mass spectrometry

A rapid confirmatory method has been developed and validated for the simultaneous identification, confirmation and quantitation of 11 nitroimidazoles in eggs by liquid chromatography tandem mass spectrometry (LC–MS/MS). The method is validated in accordance with Commission Decision 2002/657/EC and is capable of analysing metronidazole (MNZ), dimetridazole (DMZ), ronidazole (RNZ), ipronidazole (IPZ) and their hydroxy metabolites MNZ-OH, HMMNI (hydroxymethyl, methyl nitroimidazole), IPZ-OH. The method is also capable of analysing carnidazole (CRZ), ornidazole (ORZ), tinidazole (TNZ) and ternidazole (TRZ). MNZ, DMZ and RNZ have been assigned a recommended level (RL) of 3 μg kg⁻¹ by the Community Reference Laboratory (CRL) in Berlin. The developed method described in this study is easily able to detect all the nitroimidazole compounds investigated at this level and below. Egg samples are extracted with acetonitrile, and NaCl is added to help remove matrix contaminants. The acetonitrile extract undergoes a liquid–liquid wash step with hexane; it is then evaporated and reconstituted in mobile phase. The reconstituted samples are analysed by liquid chromatography tandem mass spectrometry (LC–MS/MS). The decision limits (CCα) range from 0.33 to 1.26 μg kg⁻¹ and the detection capabilities (CCβ), range from 0.56 to 2.15 μg kg⁻¹. The results of the inter-assay study, which was performed by fortifying hen egg samples (n = 18) on three separate days, show the accuracy calculated for the various analytes to range between 87.2 and 106.2%. The precision of the method, expressed as %CV values for the inter-assay variation of each analyte at the three levels of fortification (3, 4.5 and 6.0 μg kg⁻¹), ranged between 3.7 and 11.3%. A Day 4 analysis was carried out to examine species variances in eggs from different birds such as duck and quail and investigating differences in various battery and free range hen eggs.     

超高效液相色谱-串联质谱法同时快速确证检测血浆和尿液中的42种精神药物及其代谢产物

针对公共卫生突发事件和临床毒物学检测实践中亟待解决的问题,建立了血浆和尿液中42种精神药物及其代谢产物的超高效液相色谱-串联质谱(UPLC-MS/MS)快速确证分析方法。样品经乙腈沉淀后,以乙酸铵和甲醇-乙腈(1:1, v/v)混合液作为流动相进行梯度洗脱,在Acquity UPLC BEH C18色谱柱上分离后用电喷雾串联质谱法检测,采用正、负离子快速切换多反应监测模式监测,基质标准同位素内标法定量。血浆样品中待测组分的加标回收率除了奋乃静、硫利哒嗪和氯丙嗪的分别为37.6%～57.5%, 36.3%～48.3%和52.4%～67.4%外,尿液样品中待测组分的加标回收率除了曲唑酮和地西泮的分别为100%～142%和108%～177%外,血浆和尿液中其余待测组分的加标回收率分别为60.2%～125%和64.5%～126%,相对标准偏差分别为0.8%～26%和2.6%～18%(n=6);除了巴比妥类药物的检出限为20～100 mg/L外,其余药物的检出限均为0.05～2.0 mg/L。该方法简单、快速、特异性强、灵敏度高。     

Development and validation of a hydrophilic interaction liquid chromatography-tandem mass spectrometry method for the quantification of regadenoson in human plasma and its pharmacokinetic application

Regadenoson, the first selective adenosine A_2A receptor agonist, is used to perform exercise stress test during radionuclide myocardial perfusion imaging. To detect the concentration of regadenoson in human plasma, a simple, fast, and sensitive tandem mass spectrometry method was established herein. Acetonitrile was used as a protein precipitation agent. Chromatographic separation was completed in 6.5 min using a BEH HILIC column (50 × 2.1 mm, 1.7 μm). The mobile phase consisted of 10 mmol/L ammonium acetate/acetonitrile (gradient elution). To quantify regadenoson and regadenoson-d3, an API 4000 mass spectrometry in multiple reaction monitoring mode with transitions of 391.3→259.2 and 394.3→262.2, respectively, was utilized. The calibration curve was linear in the range of 0.100–50.0 μg/L, and the intrabatch and interbatch precisions were <9.7% and <13.0%, respectively, and the accuracy was 2.0–6.9%. There was no apparent matrix effect for regadenoson or regadenoson-d3. The developed method was used to study the pharmacokinetic characteristics of regadenoson in healthy Chinese subjects.     

基于超滤离心前处理的液相色谱-串联质谱法手性拆分人血浆中的亚叶酸和5-甲基四氢叶酸非对映异构体及其药代动力学应用

建立了液相色谱-串联质谱（HPLC-MS/MS）同时测定人血浆中的亚叶酸和5-甲基四氢叶酸两对非对映异构体的方法。血浆经蛋白质沉淀-超滤离心处理后,以甲氨蝶呤为内标,乙腈-10 mmol/L pH 8.0醋酸铵为流动相,通过手性HSA色谱柱（150 mm×4 mm,5 μm）进行梯度洗脱。亚叶酸非对映异构体在25~5000 μg/L范围内、5-甲基四氢叶酸非对映异构体在12.5~2500 μg/L范围内,线性关系均良好。本方法在灵敏度、精密度、准确度、基质效应、提取回收率、稳定性等方面均得到充分验证,并成功应用于125 mg/m²亚叶酸和62.5 mg/m²左旋亚叶酸的药代动力学研究。结果显示：在125 mg/m²亚叶酸剂量组,左亚叶酸和左旋-5-甲基四氢叶酸的血浆峰浓度（C_max）为（3137.917±408.837）和（1679.633±244.132）μg/L,从时间点0到最后可定量时间点的药物代谢动力学时间曲线下面积（AUC_0-t）为（7504.883±1185.101）和（14001.214±2868.949）μg/L;在62.5 mg/m²左亚叶酸剂量组,左亚叶酸和左旋-5-甲基四氢叶酸的C_max为（3187.917±387.298）和（1739.204±224.755）μg/L,AUC_0-t为（7426.664±854.825）和（14884.331±1843.353）μg/L。两剂量组主要药物代谢动力学参数均无显著差异,特征一致,吸收的速度和程度一致,能够为后期进行左亚叶酸钠生物等效性研究提供技术支持。     

Simultaneous determination of metformin and gliclazide in human plasma by liquid chromatography-tandem mass spectrometry: application to a bioequivalence study of two formulations in healthy volunteers

A rapid and sensitive liquid chromatography/tandem mass spectrometry (LC/MS/MS) method was developed and validated to simultaneously determine gliclazide and metformin in human plasma using huperzine A as the internal standard (IS). After acetonitrile-induced protein precipitation of the plasma samples, gliclazide, metformin and the IS were subjected to LC/MS/MS analysis using electro-spray ionization (ESI). Chromatographic separation was performed on a Hypersil BDS C18 column (50 mm x 2.1 mm, i.d., 3 microm). The method had a chromatographic running time of 2.0 min and linear calibration curves over the concentration ranges of 10-10,000 ng ml(-1) for gliclazide and 7.8-4678.9 ng ml(-1) for metformin. The recoveries of the method were found to be 71-104%. The lower limits of quantification (LOQ) of the method were 10.0 and 7.8 ng ml(-1) for gliclazide and metformin, respectively. The intra- and interday precision was less than 15% for all quality control samples at concentrations of 100, 500, and 2000 ng ml(-1). The validated LC/MS/MS method has been used to study bioequivalence in healthy volunteers. These results indicate that the method was efficient with a very short running time (2.0 min) for metformin and gliclazide compared to the methods reported in the literature. The presented method had acceptable accuracy, precision and sensitivity and was used in clinical bioequivalence study.     

液相色谱-串联质谱法测定吉非替尼中4种基因毒性杂质

建立了一种同时测定吉非替尼中4种基因毒性杂质3-氯-4-氟苯胺、3,4-二氟苯胺、3-氟-4-氯苯胺和3,4-二氯苯胺的高效液相色谱-串联质谱（HPLC-MS/MS）方法。用Inertsil ODS-3柱（100 mm×3.0 mm,3μm）为色谱柱,以0.1%（体积分数,下同）甲酸水溶液-0.1%甲酸乙腈溶液为流动相,在电喷雾正离子模式下进行测定。该方法在特异性、线性、精密度、准确性、稳定性和耐用性方面得到了验证。4种基因毒性杂质在0.6~96.0μg/L范围内与峰面积呈良好线性关系。检测限和定量限分别为0.2~2.0μg/L和0.6~6.0μg/L。所有杂质的回收率为91.0%~98.5%。检测后,在批号16052301和R16052501-1样品中仅检测到3-氯-4-氟苯胺,但低于杂质限度（6 mg/L）。该方法简便可靠,可用于吉非替尼中4种基因毒性杂质的测定,并为质量控制提供参考。     

Determination of 48 pesticides and their main metabolites in water samples by employing sonication and liquid chromatography-tandem mass spectrometry

In this work, a rapid and sensitive analytical multiresidue method has been developed for the simultaneous determination of 48 pesticides and 19 metabolites in waters (tap, leaching and sewage), using liquid chromatography-tandem mass spectrometry (LC-MS/MS) with triple quadrupole in selected reaction monitoring (SRM) mode. The procedure involves initial single phase extraction of samples with acetonitrile by sonication, followed by liquid-liquid partition aided by “salting out” process using NaCl. Matrix influence on recoveries was evaluated for the three waters. More than 50% of the compound presented very low signal suppression. The method presents good linearity over the range assayed 10-500 μg L⁻¹ and the most frequent detection limits was 0.05 ng mL⁻¹. The average recovery by the LC-MS/MS method obtained for these compounds varied from 74.6 to 111.2% with a relative standard deviation between 2.5 and 8.9%. The proposed method was used to determine pesticides levels in leaching water samples from 5 lysimeters from an experimental greenhouse located in Murcia.     

Development and validation of a liquid chromatography with tandem mass spectrometry method for the determination of isomangiferin in rat plasma with application to a preclinical pharmacokinetic study

A sensitive and specific liquid chromatography with tandem mass spectrometry method was firstly developed for the measurement of isomangiferin in rat plasma. Chloramphenicol was selected as the internal standard. Sample preparation was carried out through a simple one‐step protein precipitation procedure with methanol. Negative electrospray ionization was performed using multiple reaction monitoring mode with transitions of m/z 421.1/301.1 for isomangiferin, and 321.1/151.9 for chloramphenicol. The calibration curve was linear over the range of 0.1–600 ng/mL, with a lower limit of quantification at 0.1 ng/mL. The intra‐ and interday precisions (relative standard deviation) were no more than 8.2% and accuracies (relative error) were within the range of –8.4 to 2.2%. The recovery, matrix effect and stability under different conditions were all proved acceptable. The validated method has been successfully applied to a preclinical pharmacokinetic study of isomangiferin in rats for the first time.     

Method development for the determination of selected pesticides on tobacco by high-performance liquid chromatography-electrospray ionisation-tandem mass spectrometry

A method was developed for the quantitative determination of alachlor, benalaxyl, clomazone, diflubenzuron, dimethomorph, diphenamid, ethofumesate, metalaxyl, methoprene, metobromuron and piperonyl butoxide on tobacco. The pesticides were extracted with water and methanol from five different types of tobacco. The extracts were purified by partition on an extraction cartridge containing diatomaceous earth. The purified extracts were analysed by reversed-phase high-performance liquid chromatography connected to an atmospheric pressure ionisation–electrospray-triple quadrupole mass spectrometer operating in the positive ion mode. Two different transitions and their relative intensities were monitored for unambiguous identification. All pesticides presented overall recovery rates between 35% and 110%. The trueness is near 100% and the interday precision is below 15%. The limits of quantifications are equal or below the guidance residue levels proposed by the Agrochemical Advisory Committee of CORESTA, an association of organisations having scientific research relative to tobacco.