Determination of dithiocarbamate fungicide residues by liquid chromatography/mass spectrometry and stable isotope dilution assay

A rapid and very sensitive high-performance liquid chromatography/electrospray ionization mass spectrometry (LC/ESI-MS) method for the simultaneous determination of dithiocarbamate (DTC) fungicide residues in fruits and vegetables was developed. The surface extraction of samples used an alkaline buffer consisting of sodium hydrogen carbonate and DL-penicillamine. The three DTC subclasses, i.e. dimethyldithiocarbamates (DMDs), ethylenebis(dithiocarbamates) (EBDs), and propylenebis(dithiocarbamates) (PBDs), were separated on a Sequant ZIC-pHILIC column using an acetonitrile/10 mM ammonia gradient. Because of the instability of DTC residues extracted from plant samples, a stable isotope dilution assay was applied. For each DTC subclass, the limits of detection and quantification were approximately 0.03 mg kg(-1) and 0.05 mg kg(-1), respectively. Recoveries from grapes, cucumbers, tomatoes, and rucola, spiked in the range of 0.01-0.9 mg kg(-1), averaged between 90 and 100%.     

Determination of residues of 446 pesticides in fruits and vegetables by three-cartridge solid-phase extraction-gas chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry

A method was developed for determination of residues of 446 pesticides in fruits and vegetables through the use of cleanup by a 3-cartridge solid-phase extraction-gas chromatography/ mass spectrometry (GC/MS) and liquid chromatography/tandem mass spectrometry (LC/MS/MS). Fruit and vegetable samples (20 g) were extracted with 40 mL acetonitrile, salted out, and centrifuged. Half of the supernatant was passed into an Envi-18 cartridge, eluted with acetonitrile, and cleaned up with Envi-Carb and aminopropyl Sep-Pak cartridges in series after concentration of the eluates. Pesticides were eluted with acetonitrile-toluene (3 + 1, v/v), and eluates were concentrated to 0.5 mL and then added into internal standards after solvent exchange with 2 mL hexane and used for determination of 383 pesticides by GC/MS. The other half of the supernatant was concentrated to 1 mL and cleaned up with Envi-Carb and aminopropyl Sep-Pak cartridges in series. Pesticides were eluted with acetonitrile-toluene (3 + 1, v/v), and the eluates were concentrated to 0.5 mL, dried with nitrogen gas, diluted to 1.0 mL with acetonitrile-water (3 + 2, v/v), and used for determination of 63 pesticides by LC/MS/MS. The limit of detection for the method was 0.2-600 ng/g depending on the individual pesticide. In the method, fortification recovery tests at high, medium, and low levels were conducted on 6 varieties of fruits and vegetables, i.e., apples, oranges, grapes, cabbage, tomatoes, and celery, with average recoveries falling within the range of 55.0-133.8% for 446 pesticides, among which average recoveries between 60.0-120.0% accounted for 99% of the results. The relative standard deviation was between 2.1-39.1%, of which a relative standard deviation of 2.1-25.0% made up 96% of the results. Experiments proved that the method was applicable for determination of residues of 446 pesticides in fruit and vegetables.     

固相萃取–气相色谱–负化学源质谱法检测水果和蔬菜中的毒杀芬

采用改进的分散固相萃取(QuEchERs)法对样品进行前处理,建立水果和蔬菜中毒杀芬残留的气相色谱–负化学电离源质谱(GC–NCI–MS)检测方法。样品中的毒杀芬由正己烷提取,经吸附剂PSA+GCB净化,在GC–NCI–MS的选择离子扫描模式下进样分析。毒杀芬的色谱保留时间在12.5~18.0 min区间内,采用面积归一化法积分,外标法定量。毒杀芬质量浓度在0.050~2.000 mg/L范围内与色谱峰面积呈良好的线性关系,相关系数r=0.999 1。分别以蓝莓、黄桃、菠菜为基质,在0.025,0.050 mg/kg添加水平下,毒杀芬的回收率为107.2%~118.1%,测定结果的相对标准偏差为5.5%~8.8%(n=6),定量限为0.025 mg/kg。该方法检测快速,适用于水果和蔬菜中毒杀芬残留的日常检测。     

Simultaneous determination of aminopyralid, clopyralid, and picloram residues in vegetables and fruits using ultra-performance liquid chromatography/tandem mass spectrometry

A sensitive and effective method for the simultaneous quantitative determination of aminopyralid, clopyralid, and picloram in vegetables (eggplant, cucumber, and tomato) and fruits (apple and grape) was developed and validated using ultra-performance LC coupled with MS/MS. The three herbicides were successfully separated and independently confirmed in a single run. Different extraction and cleanup methods were used to optimize the pretreatment processes of the residue analysis method. The final method is straightforward and involves extraction with 1% formic acid-acetonitrile, and no complicated cleanup process is needed. Determination of the compounds was achieved within 3.0 min. Respective average recoveries using this method at four concentration levels (0.05, 0.1, 0.5, and 1.0 mg/kg) ranged from 66.5 to 109.4%, with RSDs in the range of 1.1-19.7% (n = 5) for all analytes. The LODs were below 0.010 mg/kg, and the LOQs did not exceed 0.036 mg/kg, which were lower than the maximum residue limits (MRLs) of 0.5-5.0 mg/kg clopyralid in vegetables and fruits samples, as established by the European Union. This study provides a theoretical basis for China to develop MRLs and an analytical method for aminopyralid, clopyralid, and picloram in vegetables and fruits.     

Multi-residue pesticide analysis in fruits and vegetables by liquid chromatography-time-of-flight mass spectrometry

In this work, a new multi-residue methodology using liquid chromatography-time-of-flight mass spectrometry (LC-TOF-MS) for the quantitative (routine) analysis of 15 pesticide residues has been developed. The analytical performance of the method was evaluated for different types of fruit and vegetables: pepper, broccoli, tomato, orange, lemon, apple and melon. The accurate mass measurements were compared in different matrices at significantly different concentration levels (from 0.01 to 0.5 mg/kg) obtaining accuracy errors lower than 2 ppm, which is well within the accepted limits for elemental confirmation. Linearity of response over two orders of magnitude was demonstrated (r > 0.99). Matrix effects resulting in suppression or enhancement of the response were frequently observed, most notably in broccoli and citrus. Instrumental limits of detection (LOD) were between 0.0005 and 0.03 mg/kg depending on the commodity and pesticide studied, all being within European Union regulations for food monitoring program. Finally, the methodology was applied to the analysis of two samples from an inter-laboratory exercise. The high degree of confirmation for target pesticides by accurate mass measurements demonstrated the applicability of the method in routine analysis. This study is a valuable indicator of the potential of LC-TOF-MS for quantitative multi-residue analysis of pesticides in vegetables and fruits.     

液相色谱-串联质谱法测定10种食品中四溴菊酯残留

建立了测定蔬菜、水果、茶叶、大豆等10种食品中四溴菊酯残留的高效液相色谱-串联质谱(HPLC-MS/MS)分析方法。样品以乙酸乙酯(蔬菜、水果、茶叶样品)或乙腈(大豆样品)为提取剂,上层有机相经浓缩、固相萃取小柱净化,流动相定容后,采用HPLC在Agilent ZORBAX Eclipse XDB C18色谱柱上,以甲醇和缓冲盐溶液(0.1%甲酸-10 mmol/L乙酸铵)为流动相进行梯度洗脱分离,以串联质谱在多反应监测(MRM)模式下测定,基质外标法定量。结果表明,四溴菊酯的质量浓度在20～1 000μg/L范围内线性关系良好,相关系数为0.999 8;在0.01、0.02、0.1 mg/kg(粮谷类、茶叶、大豆样品)和0.005、0.01、0.05mg/kg(果蔬类样品)加标水平下的回收率为75%～92%,相对标准偏差(RSDs)为4.0%～12.6%(n=6),定量下限(S/N≥10)为0.01 mg/kg(粮谷类、茶叶、大豆样品)和0.005 mg/kg(果蔬类样品)。该方法不受溴氰菊酯干扰,可直接测定四溴菊酯,克服了以往方法只能测定四溴菊酯和溴氰菊酯总量的不足。     

水果蔬菜中多种杀菌剂的基质固相分散液相色谱测定方法研究

采用基质固相分散(MSPD)代替液液分配和固相萃取,从蔬菜水果中提取、净化10种常用杀菌剂农药残留,用C18硅胶交联剂作为固相吸附剂,乙酸乙酯作为洗脱液,用HPLC/PDA和LC-MS进行分析检测。10种杀菌剂在0.5~5 mg/kg含量的添加回收率在65%~110%之间,相对标准偏差小于10%,使用HPLC、PDA和LC-MS的检出限分别在0.02~0.2 mg/kg和0.002~0.01 mg/kg之间。该方法节省溶剂,提取和净化一步完成,适用于新鲜水果和蔬菜中10种杀菌剂的残留分析。     

Determination of chlormequat and mepiquat in foods by liquid chromatography/mass spectrometry or liquid chromatography/tandem mass spectrometry: interlaboratory study

Interlaboratory validation studies have been performed on 2 methods for the determination of chlormequat (CLQ) and mepiquat (MPQ). Both methods used identical extraction procedures and stable isotope internal standardization but differed in the use of liquid chromatography/mass spectrometry (LC/MS) or LC/tandem mass spectrometry (LC/MS/MS) for the determination, the amount of internal standard used, and the expected limit of detection. After addition of deuterated internal standards, CLQ and MPQ were extracted with methanol-water and determined by LC//MS or LC/MS/MS with positive electrospray ionization. Eight European laboratories participated in the LC/MS method study, analyzing mushroom, pear, wheat flour, and fruit puree with residues of CLQ in the range 0.040-1.19 mg/kg and of MPQ in the range 0.041-0.39 mg/kg. For CLQ, the Horwitz ratio (HoRat) values for individual test materials/levels were in the range 0.85-1.13 with a mean of 1.00, showing good method performance. For MPQ, the Ho values for mushroom, pear (both levels), and wheat flour were in the range 0.83-0.94, again indicating good method performance. For the determination of MPQ in infant food (fruit puree) at 0.041 mg/kg, the Ho was 1.7 when a value of 0 reported by one participant was excluded. In the LC/MS/MS study, in which 11 laboratories participated, a separate sample set was analyzed with residues of CLQ in the range 0.007-1.03 mg/kg and of MPQ in the range 0.008-0.72 mg/kg. Ho values for CLQ were in the range 0.27-1.36 and for MPQ in the range 0.51-2.10, all corresponding to acceptable method performance.     

Applications of LC/ESI-MS/MS and UHPLC QqTOF MS for the determination of 148 pesticides in fruits and vegetables

This paper presented the applications of liquid chromatography electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) and ultra-high-pressure liquid chromatography electrospray ionization quadrupole time-of-flight mass spectrometry (UHPLC QqTOF MS) for the determination of 148 pesticides in fruits and vegetables. Pesticides were extracted from fruits and vegetables using a buffered QuEChERS method. Quantification was achieved using matrix-matched standard calibration curves with isotopically labeled standards or a chemical analog as internal standards in an analytical range from 5 to 500 μg/kg. The method performance parameters including overall recovery, intermediate precision, and measurement uncertainty were evaluated according to a statistically designed experiment, i.e., a nested design. For LC/ESI-MS/MS, 95% of the pesticides had recoveries between 81% and 110%; 97% had an intermediate precision ≤20%; and 95% (in fruits) or 93% (in vegetables) showed measurement uncertainty ≤40%. Compared to LC/ESI-MS/MS, UHPLC QqTOF MS showed a relatively poor repeatability and large measurement uncertainty. About 93% (in fruits) or 94% (in vegetables) of the pesticides had recoveries between 81% and 110%; 86% (in fruits) or 90% (in vegetables) had an intermediate precision ≤20%; and 79% (in fruits) or 88% (in vegetables) showed measurement uncertainty ≤40%. LC/ESI-MS/MS proved to be the first choice for quantification or pre-target analysis due to its superior sensitivity and good repeatability. UHPLC QqTOF MS provided accurate mass measurement and isotopic patterns, and was an ideal tool for post-target screening and confirmation.     

固相萃取-气相色谱/质谱法分析水果和蔬菜中残留的嘧菌酯

建立了多种水果和蔬菜中嘧菌酯残留的气相色谱/质谱分析方法。首先用乙酸乙酯-环己烷(体积比为1∶1)对样品中的嘧菌酯进行超声波提取,经硅胶固相萃取小柱对样品提取液进行净化、富集,采用气相色谱/质谱法以选择离子监测模式(m/z 344,372,388,403定性,m/z 344定量)进行检测。实验结果表明,嘧菌酯在0.01～1.0 mg/kg浓度范围内呈线性,其相关系数r>0.99。在低、中、高3个添加水平,嘧菌酯的回收率为85.2%～98.2%,相对标准偏差为5.8%～21.5%。方法的检测限不大于0.01 mg/kg,定量限不大于0.05 mg/kg。     

Multi-residue screening of pesticides in vegetables,fruits and baby food by stir bar sorptive extraction-thermal desorption-capillary gas chromatography-mass spectrometry

The performance of stir bar sorptive extraction (SBSE) for the enrichment of pesticides from vegetables, fruits and baby food samples is discussed. After extraction with methanol, an aliquot is diluted with water and SBSE is performed for 60 min. By applying a new thermal desorption unit (TDU), fully automated and unattended desorption of 98 stir bars is feasible, making SBSE very cost-effective. The presence of pesticide residues is elucidated with the retention time locked gas chromatography–mass spectroscopy method (RTL-capillary GC–MS). With SBSE–RTL-capillary GC–MS operated in the scan mode, more than 300 pesticides can be monitored in vegetables, fruits and baby food. The multi-residue method (MRM) described provides detectabilities from the mg/kg (ppm) to the sub-μg/kg (ppb) level, thereby complying with the maximum residue levels (MRLs) set by regulatory organizations for pesticides in different matrices. Several examples, i.e. pesticide residues in lettuce, pears, grapes and baby food, illustrate the potential of SBSE–RTL-capillary GC–MS.     

Determination of chlorantraniliprole residues in crops by liquid chromatography coupled with atmospheric pressure chemical ionization mass spectrometry/mass spectrometry

An analytical method is presented for the determination of chlorantraniliprole residues in crops. Chlorantraniliprole residues were extracted from crop matrixes with acetonitrile after a water soak. The extracts were passed through a strong anion-exchange (SAX) SPE cartridge stacked on top of a reversed-phase (RP) polymer cartridge. After both cartridges were rinsed and vacuum-dried, the SAX cartridge was removed, and chlorantraniliprole was eluted from the RP polymer cartridge with acetonitrile. The acetonitrile eluate was evaporated to dryness, reconstituted, and analyzed using an LC/MS/MS instrument equipped with an atmospheric pressure chemical ionization source. The method was successfully validated at 0.010, 0.10, and 10 mg/kg for the following crop matrixes: potatoes, sugar beets (tops), lettuce, broccoli, soybeans, soybean forage, tomatoes, cucumbers, oranges, apples, pears, peaches, almonds (nutmeat), rice grain, wheat grain, wheat hay, corn stover, alfalfa forage, cottonseed, grapes, and corn grain. The average recoveries from all crop samples fortified at the method LOQ ranged from 91 to 108%, with an overall average recovery of 97%. The average recoveries from all crop samples fortified at 10 times the method LOQ ranged from 89 to 115%, with an overall average recovery of 101%. For all of the fortified control samples analyzed in this study, the overall average recovery was 99%.     

Multi-residue determination of plant growth regulators in apples and tomatoes by liquid chromatography/tandem mass spectrometry

A sensitive and rapid multi-residue analytical method for plant growth regulators (PGRs) (i.e., chlormequat, mepiquat, paclobutrazol, uniconazole, ethephon and flumetralin) in apples and tomatoes was developed using high-performance liquid chromatography/tandem mass spectrometry (HPLC/MS/MS). A homogenised sample was extracted with a mixture of methanol/water (90:10, v/v) and adjusted to pH <3 with formic acid. Primary secondary amine (PSA) adsorbent was used to clean up the sample. The determination was performed using electrospray ionisation (ESI) and a triple quadrupole (QqQ) analyser. Under the optimised method, the results showed that, except for ethephon, the recoveries were 81.8-98.1% in apples and tomatoes at the spiked concentrations of 0.005 to 2 mg/kg, with relative standard deviations (RSDs) of less than 11.7%. The limits of quantification (LOQs) were lower than their maximum residue limits (MRLs). The procedure was concluded as a practical method to determine the PGR residues in fruit and vegetables and is also suitable for the simultaneous analysis of the amounts of samples for routine monitoring. The analytical method described herein demonstrates a strong potential for its application in the field of PGR multi-residue analysis to help assure food safety.     

Development and validation of a routine multiresidue method for determining 140 pesticides in fruits and vegetables by gas chromatography/tandem quadrupole mass spectrometry

A GC/tandem quadrupole MS/MS method was developed and validated for the determination of the residues of 140 pesticides in fruits and vegetables. Pesticides were extracted from samples by using a miniaturized acetonitrile-based extraction technique known as the quick, easy, cheap, effective, rugged, and safe (QuEChERS) method. Validation studies were carried out on carrots, tomatoes, and strawberries. In order to reduce systematic errors due to a matrix-induced effect, quantification was carried out using matrix-matched standard calibration curves. The recovery and precision results satisfied the European Union criteria (i.e., average recoveries were in the range 70-120% with RSDs < or = 20%) for 125 of the 140 pesticides at a spiking level of 0.01 mg/kg. At the higher spiking levels, there were just two instances of overall average recovery < 70% (chlorothalonil and captan). The measurement uncertainty was estimated following a "top down" approach as being 21 and 35%, on average, based on validation and ongoing recovery data, respectively (coverage factor k = 2, confidence level 95%). Practical application to 541 samples of apples, tomatoes, strawberries, cucumbers, currants, mushrooms, carrots, peppers, pears, onions, and gooseberries under strict QC conditions demonstrated the ruggedness of the total procedure.     

Determination of dithiocarbamates and metabolites in plants by liquid chromatography-mass spectrometry

A quantitative matrix solid-phase dispersion and liquid chromatography-atmospheric pressure chemical ionization mass spectrometry (LC-APCI-MS) method is outlined for the simultaneous analysis of dithiocarbamates (DTCs) and their degradation products in plants. Compounds analyzed are dazomet, disulfiram, thiram and the metabolites ethylenthiourea and propylenthiourea. The performance of two different sample preparation protocols, the proposed one and other based on solid-phase extraction, as well as, of both atmospheric pressure ionization sources, APCI and electrospray, were compared. The effect of several parameters on the extraction, separation and detection was studied. Dithiocarbamates and metabolites were dispersed with carbograph, eluted with a mixture of dichloromethane-methanol, and then, identified by monitoring the base peak of the spectra corresponding to [M + H]+. The method was validated for avocados, cherries, lemons, nuts, oat, oranges, peaches, rice and tomatoes. Average recoveries varied from 33 to 109%, and relative standard deviation were between 4 and 21% with limits of quantification ranged from 0.25 to 2.5 mg kg(-1), except for thiram and disulfiram, which were not recovered from fruits with high acid content. The procedure was applied to the determination of DTCs and their metabolites in fruits, vegetables and cereals taken from different markets of Valencia, Spain.     

Determination of pesticide residues in foods by acetonitrile extraction and partitioning with magnesium sulfate: collaborative study

A collaborative study was conducted to determine multiple pesticide residues in fruits and vegetables using a quick, simple, inexpensive, and effective sample preparation method followed by concurrent analysis with gas chromatography/mass spectrometry (GC/MS) and liquid chromatography/ tandem mass spectrometry (LC/MS/MS). For short, the method is known as QuEChERS, which stands for quick, easy, cheap, effective, rugged, and safe. Twenty representative pesticides were fortified in 3 matrixes (grapes, lettuces, and oranges) at 3 duplicate levels unknown to the collaborators ranging from 10 to 1000 ng/g. Additionally, 8 incurred pesticide residues were determined. Thirteen laboratories from 7 countries provided results in the study, and a variety of different instruments were used by collaborators. The QuEChERS procedure simply entails 3 main steps: (1) a 15 g homogenized sample is weighed into a 50 mL centrifuge tube to which 15 mL acetonitrile containing 1% HOAc is added along with 6 g MgSO4 and 1.5 g NaOAc, and the tube is shaken and centrifuged; (2) a portion of the extract is mixed with 3 + 1 (w/w) MgSO4-primary secondary amine sorbent (200 mg/mL extract) and centrifuged; and (3) the final extract is analyzed by GC/MS and LC/MS/MS. To detect residues <10 ng/g in GC/MS, large-volume injection of 8 microL is typically needed, or the extract can be concentrated to 4 g/mL in toluene, in which case 2 microL splitless injection is used. In the study, the averaged results for data from 7-13 laboratories (not using internal standardization) for the 18 blind duplicates at the 9 spiking levels in the 3 matrixes are as follows [%recovery and reproducibility relative standard deviation (RSD(R), %)]: atrazine, 92 (18); azoxystrobin, 93 (15); bifenthrin, 90 (16); carbaryl, 96 (20); chlorothalonil, 70 (34); chlorpyrifos, 89 (25); cyprodinil, 89 (19); o,p'-DDD, 89 (18); dichlorvos, 82 (21); endosulfan sulfate, 80 (27); imazalil, 77 (33); imidacloprid, 96 (16); linuron, 89 (19); methamidophos, 87 (17); methomyl, 96 (17); procymidone, 91 (20); pymetrozine, 69 (19); tebuconazole, 89 (15); tolylfluanid (in grapes and oranges), 68 (33); and trifluralin, 85 (20). For incurred pesticides, kresoxim-methyl (9.2 +/- 3.2 ng/g) and cyprodinil (112 +/- 18) were found in the grapes; permethrins (112 +/- 41), lamda-cyhalothrin (58 +/- 11), and imidacloprid (12 +/- 2) were determined in the lettuces; and ethion (198 +/- 36), thiabendazole (53 +/- 8), and imazalil (13 +/- 4) were determined in the oranges. Chlorpyrifosmethyl (200 ng/g) was used as a quality control standard added during sample homogenization and yielded 86% recovery and 19% RSD(R). Intralaboratory repeatabilities for the method averaged 9.8% RSD for all analytes. The results demonstrate that the method is fit-for-purpose to monitor many pesticide residues in fruits and vegetables, and the Study Director recommends that it be adopted Official First Action.     

高效液相色谱-二极管阵列检测法测定小麦粉及面粉改良剂中福美双

福美双是重要的二硫代氨基甲酸酯(DTC)杀菌剂,在小麦中使用限量以1 mg/kg二硫化碳(CS2)计.目前我国相关检测方法是针对二硫代氨基甲酸酯一类的化合物,二硫代氨基甲酸酯通过与酸反应生成CS2,采用光谱法或色谱法测定CS2,间接实现二硫代氨基甲酸酯测定.该方法无法特异性实现对福美双的检测,因此开展小麦粉中福美双检测...     

气相色谱-三重四极杆串联质谱法快速测定蔬菜水果中129种农药的残留量

采用QuEChERS方法结合气相色谱-串联质谱法(GC-MS/MS)建立了蔬菜、水果中129种农药残留同时检测的分析方法。试样用1%乙酸乙腈均质提取,采用混合型固相分散萃取剂净化后,用GC-MS/MS在多反应离子监测(MRM)模式下进行检测,外标法定量。结果表明,129种药物在一定的含量范围内线性关系良好,相关系数(r2)均大于0.98;不同基质在10 μg/kg添加水平下大部分农药的平均回收率为66.2%～124.7%,相对标准偏差(RSD)为0.9%～24.4%;方法的定量限(LOQ)为0.03～16.7 μg/kg。结果表明,该方法简便快速、灵敏可靠、经济有效,适用于蔬菜、水果中农药多残留的同时快速筛查测定。     

Determination of histamine in tomatoes by liquid chromatography/mass spectrometry

The histamine level in tomato fruits and pastes was determined by 2 orthogonal techniques as a means of comparing accuracy. Close statistical agreement was found between assays for free histamine by capillary electrophoresis (with UV absorbance detection), and for the dansyl derivative by reversed-phase liquid chromatography (LC). Both techniques have adequate sensitivity for the analysis of endogenous histamine in tomatoes, but LC/electrospray tandem mass spectrometry was more sensitive by at least an order of magnitude, down to a level of 0.05 mg/kg.     

超高效液相色谱-串联质谱法测定蔬菜和水果中腈吡螨酯残留量

建立了蔬菜和水果中腈吡螨酯残留量的超高效液相色谱-串联质谱(UPLC-MS/MS)分析方法。样品经乙腈均质提取,混合使用乙二胺-N-丙基硅烷(PSA)和C18两种基质分散净化剂净化,净化液过膜后直接进行UPLC-MS/MS检测。通过考察腈吡螨酯在不同果蔬样品中的基质效应发现,采用UPLC-MS/MS检测蔬菜和水果中腈吡螨酯残留量时,腈吡螨酯在不同种类样品中存在不同程度的基质减弱效应,采用空白基质溶液稀释标准建立校正的标准曲线外标法定量以消除基质效应。结果表明,腈吡螨酯在0.05~10μg/L浓度范围内具有良好的线性关系,相关系数不低于0.999 6。在0.000 05~2 mg/kg范围内进行加标回收率实验,平均回收率为81.1%~99.3%,相对标准偏差为4.7%~9.3%,方法的定量下限为0.043μg/kg,检出限为0.013μg/kg。