Levels of bisphenol A in canned liquid infant formula products in Canada and dietary intake estimates

A sensitive, efficient, and reproducible method, based on solid phase extraction and derivatization with acetic anhydride followed by gas chromatography-mass spectrometry in selected-ion monitoring mode, was developed for the determination of bisphenol A (BPA) in liquid infant formula. The method quantification limit was 0.5 ng g(-1). Extraction recoveries were 85-94% over the concentration range of 2.5-20 ng g(-1). Good reproducibility of the method was observed at levels of 0.54 and 10.4 ng g(-1) with relative standard deviations of 5.0 and 2.8%, respectively. The method was used to analyze samples of 21 canned liquid infant formula products for BPA. BPA was detected in all samples at levels ranging from as low as 2.27 ng g(-1) to as high as 10.2 ng g(-1). The probable daily intakes of BPA due to consumption of canned liquid infant formula were estimated for infants from premature to 12-18 months of age. The maximum probable daily intake of BPA was 1.35 microg kg(-1) of body weight day(-1) for 0-1-month-old infants with the maximum formula intake, which is below the provisional tolerable daily intake for BPA established by Health Canada, 25 microg kg(-1) of body weight day(-1).     

Simultaneous quantitation of 2-acetyl-4-tetrahydroxybutylimidazole, 2- and 4-methylimidazoles, and 5-hydroxymethylfurfural in beverages by ultrahigh-performance liquid chromatography-tandem mass spectrometry

An ultrahigh-performance liquid chromatography (UHPLC) tandem mass spectrometric (MS/MS) method was developed for the simultaneous quantification of 2-acetyl-4-tetrahydroxybutylimidazole (THI), 2- and 4-methylimidazoles (2-MI and 4-MI), and 5-hydroxymethylfurfural (HMF) in beverage samples. A C30 reversed-phase column was used in this method, providing sufficient retention and total resolution for all targeted analytes, with an MS/MS instrument operated in selected reaction monitoring (SRM) mode for sensitive and selective detection using isotope-labeled 4-methyl-d(3)-imidazole (4-MI-d(3)) as the internal standard (IS). This method demonstrates lower limit of quantification (LLOQ) at 1 ng/mL and coefficient of determination (r(2)) >0.999 for each analyte with a calibration range established from 1 to 500 ng/mL. This method also demonstrates excellent quantification accuracy (84.6-105% at 5 ng/mL, n = 7), precision (RSD < 7% at 5 ng/mL, n = 7), and recovery (88.8-99.5% at 10, 100, and 200 ng/mL, n = 3). Seventeen carbonated beverage samples were tested (n = 2) in this study including 13 dark-colored beverage samples with different flavors and varieties and 4 light-colored beverage samples. Three target analytes were quantified in these samples with concentrations in the range from 284 to 644 ng/mL for 4-MI and from 706 to 4940 ng/mL for HMF. THI was detected in only one sample at 6.35 ng/mL.     

Analysis of patulin in apple juice by diphasic dialysis extraction with in situ acylation and mass spectrometric determination.

A procedure combining diphasic dialysis extraction with in situ acylation and gas chromatography/mass spectrometry (GC/MS) determination was developed for detection and quantification of the mycotoxin patulin in apple juice. Apple juice samples spiked with 4-N,N-dimethylaminopyridine were dialyzed using methane chloride and acetic anhydride inside dialysis tubing. Patulin was derivatized into its acetate and collected in the tubing after diphasic dialysis and was directly determined using GC/MS with the selective ion monitoring mode without further concentration and cleanup steps. Quantification was carried out by a calibration curve with an internal standard of correlation. The appropriate parameters of both dialysis and derivatization were examined. The linear range of the calibration curve was found to be 10-250 microg/L for patulin, and the limit of quantification was 10 microg/L. Levels of patulin ranging from 0 to 107.2 microg/L with 77-109% recovery were found in 10 apple samples. The technique combining diphasic dialysis extraction and acylation was demonstrated and showed potential for other applications.     

珠三角地区鱼塘水体中双酚A污染及其生态风险评价

对地处珠三角的中山市鱼塘表层水及底泥中双酚A(BPA)污染水平进行了测定分析,结果表明:鱼塘表层水样品中BPA检出率为100%,底泥样品中BPA检出率为44.4%.鱼塘表层水中BPA残留量为0.96～4.51μg·L-1,平均浓度为3.29μg·L-1;底泥中BPA含量较低,浓度范围为0.19～1.31 ng·g-1(干重),平均浓度为0.23 ng·g-1(干重).相关及回归分析表明,除pH及COD外,BPA残留量与大部分环境因子关系不密切.参照EC/PNEC体系,BPA在中山鱼塘水体中的残留水平不会导致生态风险.     

Liquid chromatography-electrospray ionization-mass spectrometry method in multiple reaction monitoring mode to determine 17alpha-ethynylestradiol residues in cattle hair without previous digestion

A liquid chromatography-mass spectrometric (LC-MS/MS) method has been developed for determination of ethynylestradiol residues in cattle hair. Hair samples were pulverized with a cryogenic mill followed by a simple extraction with acetonitrile. A dansyl derivatization procedure to improve ethynylestradiol detection was used before the LC-MS/MS analysis in multiple reaction monitoring (MRM) mode using alpha-estradiol as an internal standard. The method was validated following the latest EU guidelines using blank hair samples spiked at 2 ng g(-1). The detection capability (CCbeta) was less than 2 ng g(-1), and the decision limit (CCalpha) was 1 ng g(-1). Incurred samples obtained 56 days after cow treatment with ethynylestradiol were analyzed, and the presence of ethynylestradiol in the hair was confirmed in all cases.     

Determination of low levels of perchlorate in lettuce and spinach using ion chromatography-electrospray ionization mass spectrometry (IC-ESI-MS)

A sample preparation method was developed to quantify environmentally relevant (low micrograms per liter) concentrations of perchlorate (ClO4(-)) in leafy vegetables using IC-ESI-MS. Lettuce and spinach were macerated, centrifuged, and filtered, and the aqueous extracts were rendered water-clear using a one-step solid-phase extraction method. Total time for extraction and sample preparation was 6 h. Ion suppression was demonstrated and was likely due to unknown organics still present in the extract solution after cleanup. However, this interference was readily eliminated using a Cl(18)O4(-) internal standard at 1 microg/L in all standards and samples. Hydroponically grown perchlorate-free butterhead lettuce was spiked to either 10.3 or 37.7 microg/kg of fresh weight (FW), and recoveries were between 91 and 98% and between 93 and 101%, respectively. Five types of lettuce and spinach from a local grocery store were then analyzed; they contained from 0.6 to 6.4 microg/kg of FW. Spike recoveries using the store-bought samples ranged from 89 to 100%. The method detection limit for perchlorate in plant extracts is 40 ng/L, and the corresponding minimum reporting limit is 200 ng/L or 0.8 microg/kg of FW.     

Determination of 2,4,6-trichloroanisole and 2,4,6-tribromoanisole in wine using microextraction in packed syringe and gas chromatography-mass spectrometry

A selective and fast method for the quantitative determination of 2,4,6-trichloroanisole (TCA) and 2,4,6-tribromoanisole (TBA) in wine was developed. Microextraction in packed syringe (MEPS) was optimized for the extraction and preconcentration of the analytes using extremely small volume samples (0.1-1 mL). For GC-EI-MS, the limit of detection (LOD) for red and white wine was in the range 0.17-0.49 microg L(-1) for TCA and TBA. In addition to GC-EI-MS both GC-NCI-MS and GC-HRMS were used to further improve both selectivity and sensitivity. The lowest LODs were achieved using GC-HRMS in the EI mode. In red and white wine samples the LODs were between 0.22-0.75 ng L(-1) for TCA and TBA. The reproducibility and linearity for the GC-HRMS method was good, with RSD-values of 4-10% for spiked red wine samples at 1 ng L(-1) and linearity with R (2) > 0.962 over a concentration range of 1 to 100 ng L(-1).     

Naturally occurring estrogens in processed milk and in raw milk (from gestated cows)

The occurrence of the steroid hormones estrone (E1), 17alpha-estradiol (alphaE2), 17beta-estradiol (betaE2), and estriol (E3) in processed bovine milk with different fat contents and in raw milk from (non)gestated cows was investigated. Following liquid extraction, optional enzymatical deconjugation, C18 solid-phase extraction, and derivatization, estrogens were analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Free and deconjugated E1 (6.2-1266 ng/L) was the major estrogen followed by alphaE2 (7.2-322 ng/L) and betaE2 (5.6-51 ng/L), whereas E3 was detected regularly at the detection limit of 10 ng/L. The lowest and highest concentrations were determined in raw milk from nonpregnant and from cows in the third trimester of gestation, respectively. The estrogen concentration in processed milk coincides with that of raw milk between first and second trimesters, reflecting the contribution of lactating pregnant cows to the final consumable product. The daily intake of total investigated estrogens through milk is 372 ng, which is dramatically more than currently recognized.     

Accelerated solvent extraction of ochratoxin a from rice samples

In this paper, accelerated solvent extraction (ASE) for the analysis of ochratoxin A (OTA) is applied for the first time. Optimization of the method is given for the extraction of OTA from rice samples. Several parameters such as type of solvent, temperature, pressure, static time, and cell size were investigated thoroughly to find the optimal extraction conditions. The optimum ASE operating conditions were methanol as extraction solvent, 1500 psi, 40 degrees C, 5 min of static time, 50% flush volume, 60 s of purge, 1 cycle, and 11 mL cell size. The total extraction time was approximately 15 min. OTA was determined by liquid chromatography coupled with a fluorescence detector and confirmed by methyl ester derivatization. The analytical performance of the method was monitored with quality control parameters. Finally, the optimized method was used to evaluate 12 rice samples, 1 of which was positive with an OTA content of 4.17 ng/g. The proposed method offers the possibility of a fast and simple process to obtain a quantitative extraction of OTA.     

Migration of bisphenol A from polycarbonate baby and water bottles into water under severe conditions

The isotope dilution headspace solid-phase microextraction and gas chromatography-mass spectrometry method for bisphenol A (BPA) developed previously was used successfully in a BPA migration study at 70 degrees C of polycarbonate baby and reusable water bottles recently sold in Canada by using the whole bottles instead of pieces cut from the bottles. Migration of BPA from the PC bottles heated at 70 degrees C was found to increase over the time in the quadratic equations. Migration levels of BPA in water varied from 228 to 521 microg L (-1) or from 0.26 to 0.90 microg cm (-2) after being heated at 70 degrees C for 6 days. The average migration rates of BPA from the PC bottles into water at 70 degrees C ranged from 1.84 to 4.83 ng cm (-2) h (-1).     

Simultaneous analysis of free and conjugated estrogens, sulfonamides, and tetracyclines in runoff water and soils using solid-phase extraction and liquid chromatography-tandem mass spectrometry

The ability to monitor multiple analytes from various classes of compounds in a single analysis can increase throughput and reduce cost when compared to traditional methods of analyses. This method for analyzing free (parent estrogen) and conjugated estrogens (metabolites) along with sulfonamides and tetracyclines utilizes a high pH (10.4) mobile phase with an ammonium hydroxide buffer for both positive- and negative-mode electrospray ionization. A single-step sample preparation by solid-phase extraction (SPE) was used to isolate and concentrate all analytes simultaneously. The analytical method was developed and validated for recoveries at 3 concentration levels for water and soil and produced recoveries of 42-123% and 21-105% respectively. Method detection limits ranged from 0.3 to 1.0 ng/L for water samples and 0.01 to 0.1 ng/g for soils. The method quantification limit ranged from 0.9 to 3.3 ng/L for water samples and 0.06 to 0.7 ng/g for soils. The single-point standard addition calibration procedure was validated across a linear range of MQL to 100 ng/L with ≥82% accuracy against a matrix matched standard curve. Furthermore, sorption of tetracyclines onto glassware was investigated and minimized by 10% using nitric acid-rinsed glassware, while separation parameters were further optimized based on retention time and signal responses. This method has been used for the quantification of estrogens, tetracyclines, and sulfonamides in soil and runoff waters with multiple compounds detected simultaneously in a single analysis.     

Assay of ochratoxin A in wine and beer by high-pressure liquid chromatography photodiode array and gas chromatography mass selective detection.

To routinely assay the concentrations of ochratoxin A (OTA) in wines and beers, two new methods were developed and evaluated. The first utilized solid-phase extraction on a C(18) cartridge to achieve a 100-fold sample concentration followed by high-performance liquid chromatography on a C(18) column with gradient elution and quantitation at 333 nm by means of a photodiode array detector. Positive confirmation can be carried out by purity and match-factor analysis as well as peak shift following esterification with BF(3). Total run time is 28 min. The limits of detection (LOD) and quantitation (LOQ) are 0.05 and 0.10 microg/L, respectively. Recovery and imprecision ranged from 83 to 94% and from 4.0 to 8.9%, respectively. With a throughput of 35 assays per working day, this method is ideal for routine OTA analysis. It was used to survey the concentrations of OTA in 942 wines (2 of which gave values between 0.1 and 0.2 microg/L) and 107 beers (2 of which gave values between 0.05 and 0.1 microg/L). OTA was detected more frequently in red than white wines, with the highest incidence in red wines from Spain and Argentina. There was no association between OTA and country of origin or beverage type among the beers analyzed. The second method utilized gas chromatography with mass selective detection monitoring eight specific ions, preceded by extraction in dichloromethane and derivatization with bis[trimethylsilyl]trifluoroacetamide. LOD and LOQ were 0.1 and 2 microg/L, respectively; recovery and imprecision were 69-75 and 9.0-11.1%, respectively. The method is not suitable for routine quantitation but is potentially useful as a confirmatory tool for samples with OTA > or =0.1 microg/L.     

Determination of postharvest fungicides in fruit juices by solid-phase extraction followed by liquid chromatography electrospray time-of-flight mass spectrometry

A multiresidue method using liquid chromatography-time-of-flight mass spectrometry (LC-TOFMS) has been developed for the quantitative analysis of five widely used postharvest fungicides (carbendazim, thiabendazole, imazalil, prochloraz, and iprodione) and two of their transformation products (imazalil and prochloraz metabolites) in fruit juices. LC-TOFMS in positive electrospray ionization mode was used to quantify and confirm trace levels of these fungicides in fruit juices. The proposed method consists of a sample treatment step based on solid-phase extraction using hydrophilic-lipophilic-balanced polymer-based reverse-phase SPE cartridges (Oasis HLB) and methanol as an eluting solvent. Fruit-juice extracts spiked at different fortification levels (10 and 20 microg L(-1)) yielded average recoveries in the range of 71-109% with RSD (%) below 15%. Subsequent identification, confirmation, and quantitation were carried out by LC-TOFMS analysis. The confirmation of the target species was based on accurate mass measurements of protonated molecules ([M+H]+) and fragment ions, obtaining routine accuracy errors lower than 2 ppm in most cases. The obtained limits of detection (LODs) of the proposed method were in the range of 0.08-0.45 microg L(-1). Finally, the proposed method was successfully applied to the analysis of 23 fruit juice samples collected from different European countries and the United States, showing the potential applicability of the method in routine analysis. Over 50% of the samples tested contained pesticide residues, but relatively low concentration levels were found.     

Gas chromatographic determination of N-nitrosamines in beverages following automatic solid-phase extraction

A semiautomatic method for the determination of seven N-nitrosamines in beverages by gas chromatography with nitrogen-phosphorus detection is proposed. Beverage samples are aspirated into a solid-phase extraction module for preconcentration and cleanup. The influence of the experimental conditions was examined by using various sorbents among which LiChrolut EN was found to provide quantitative elution and the highest preconcentration factors of all. The proposed method is sensitive, with limits of detection between 7 and 33 ng/kg, and precise, with relative standard deviations from 4.3% to 6.0%. The recoveries of N-nitrosamines from beverage samples spiked with 0.5 or 1 microg/kg concentrations of these compounds ranged from 95% to 102%. The method was successfully applied to the determination of residues of the studied N-nitrosamines in beverages including beer, wine, liquor, whisky, cognac, rum, vodka, grape juice, cider, tonic water, and soft drinks. The analytes were only detected in beer samples, positives being confirmed by gas chromatography coupled with impact ionization mass spectrometry.     

Speciation analysis of mercury in cereals by liquid chromatography chemical vapor generation inductively coupled plasma-mass spectrometry

A simple and rapid procedure for the separation and determination of inorganic, methyl, and ethyl mercury compounds was described using liquid chromatography (LC) followed by vapor generation inductively coupled plasma-mass spectrometry (VG-ICP-MS). Well resolved chromatograms were obtained within 5 min by reversed-phase liquid chromatography with a C8 column as the stationary phase and a pH 4.7 solution containing 0.5% v/v 2-mercaptoethanol and 5% v/v methanol as the mobile phase. The separated mercury compounds were converted to mercury vapors by an in situ nebulizer/vapor generation system for their introduction into ICP. The concentrations of NaBH4 and HNO3 required for vapor generation were also optimized. The method was applied for the speciation of mercury in reference materials NIST SRM 1568a Rice Flour and NIST SRM 1567a Wheat Flour and also rice flour and wheat flour samples purchased locally. The accuracy of the procedure was verified by analyzing the certified reference material NRCC DOLT-3 Dogfish Liver for methyl mercury. Precision between sample replicates was better than 13% for all the determinations. The detection limits of the mercury compounds studied were in the range 0.003-0.006 ng Hg mL(-1) in the injected solutions, which correspond to 0.02-0.06 ng g(-1) in original flour samples. A microwave-assisted extraction procedure was adopted for the extraction of mercury compounds from rice flour, wheat flour, and fish samples using a mobile phase solution.     

Sample extraction method combining micellar extraction-SPME and HPLC for the determination of organochlorine pesticides in agricultural soils

A method for the determination of organochlorine pesticides in soil samples combining microwave assisted micellar extraction (MAME) with solid-phase microextraction (SPME) and high-performance liquid chromatography-UV has been developed. A mixture of two nonionic surfactants (polyoxyethylene 10 lauryl ether and polyoxyethylene 10 stearyl ether) was used for the extraction of pesticides from agricultural soils, and different types of SPME fibers were compared. The different parameters which affect extraction efficiency in the SPME procedure were optimized such as extraction time and temperature. The method developed involves extraction and preconcentration for the target analytes in soil samples. The analytical parameters were also studied and good recoveries obtained, RSD being lower than 10% and detection limits ranging between 36 and 164 ng g(-1) for the pesticides studied. The proposed method was successfully applied to the determination of some organochlorine pesticides in several kinds of agricultural soil samples with different characteristics.     

Determination of bisphenol a and bisphenol B residues in canned peeled tomatoes by reversed-phase liquid chromatography

Bisphenol A (BPA) and bisphenol B (BPB) concentrations were determined in peeled canned tomatoes of different brands bought in Italian supermarkets. Tomato samples analyzed were packaged in cans coated with either epoxyphenolic lacquer or low BADGE enamel. A solid phase extraction (SPE) was performed on C-18 Strata E cartridge followed by a step on Florisil cartridge. Detection and quantitation were performed by a reversed phase high-performance liquid chromatography (RP-HPLC) method with both UV and fluorescence detection (FD). On the total of 42 tested tomato samples, BPA was detected in 22 samples (52.4%), while BPB was detected in 9 samples (21.4%). BPA and BPB were simultaneously present in 8 of the analyzed samples. The levels of BPA found in this study are much lower than the European Union migration limits of 3 mg/kg food and reasonably unable to produce a daily intake exceeding the limit of 0.05 mg/kg body weight, established by European Food Safety Authority.     

Determination of fluoroquinolones in milk samples by postcolumn derivatization liquid chromatography with luminescence detection

A liquid chromatography (LC) method with luminescence detection for the determination of eight quinolone antibiotics is reported. The system encompasses three consecutive steps: (a) chromatographic separation using reverse-phase mode (RP-LC), (b) postcolumn derivatization reaction, and (c) luminescence detection by monitoring fluorescence (FL) and time-resolved (TR) signals. The derivatization step is based on the reaction between quinolones and terbium(III) to form luminescent chelates, which were determined at lambda(ex) 340 and lambda(em) 545 nm (FL mode) or at lambda(ex) 281 and lambda(em) 545 nm (TR mode). Dynamic ranges of the calibration graphs, obtained with standard solutions of analytes and FL and TR modes, respectively, were 190-3500 and 316-2000 ng mL-1 for marbofloxacin, 8-3500 and 8.1-1500 ng mL-1 for ciprofloxacin, 6.2-3500 and 13-1500 ng mL-1 for danofloxacin, 7.4-3500 and 8.4-1500 ng mL-1 for enrofloxacin, 14-3500 and 20-2000 ng mL-1 for sarafloxacin, 12.5-3500 and 13.9-1200 ng mL-1 for difloxacin, 7.6-3500 and 13-3000 ng mL-1 for oxolinic acid, and 9-2000 and 130-3000 ng mL-1 for flumequine. Limit of detection values obtained using FL and TR modes, respectively, were 60 and 95 ng mL-1 for marbofloxacin, 2 and 2.4 ng mL-1 for ciprofloxacin, 1.9 and 3.9 ng mL-1 for danofloxacin, 2.2 and 2.5 ng mL-1 for enrofloxacin, 3.8 and 7 ng mL-1 for sarafloxacin, 4 and 4.2 ng mL-1 for difloxacin, 2.3 and 4 ng mL-1 for oxolinic acid, and 2.7 and 40 ng mL-1 for flumequine. The precision was established at two concentration levels of each analyte and expressed as the percentage of relative standard deviation with values ranging between 1.9 and 7.8%. The validation procedure for the analysis of samples was carried out using European Community recommendations, and the decision limit and detection capability were calculated for bovine whole milk. The method was applied to whole, semiskimmed, and skimmed milk samples spiked with the target analytes, and the recoveries ranged between 93.3 and 106.0%.     

Steviol quantification at the picomole level by high-performance liquid chromatography

A simple and highly sensitive reversed-phase high-performance liquid chromatographic method (RP-HPLC) has been developed for the determination of steviol (SV) using dihydroisosteviol (DHISV) as an internal standard (IS). SV and DHISV were derivatized by reaction of the acids with 4-(bromomethyl)-7-methoxycoumarin in an aprotic solvent (DMF or acetone). The resulting ester derivatives were separated on an ODS column (250 x 4.6 mm i.d., 5 microm particle size) using fluorescence detection with excitation at 321 nm and emission at 391 nm. The mobile phase consisted of acetonitrile/water (80:20 v/v) with a flow rate of 1 mL min(-)(1). A linear relationship was observed for concentrations between 0.5 and 50 microg/mL of SV, and the detection limit was 100 pg. For application of this method to samples of beer fortified with stevioside, a simple procedure for extraction of the beer with diethyl ether and derivatization in DMF was applied. Whereas beer samples spiked with SV gave a linear response over the range 0.1-15 microg/mL beer, no SV could be detected in beer samples enriched in stevioside that had been stored for over 3 years. The application of the method to plant samples involved preparation of an acid fraction containing the SV analyte, derivatization, and sample cleanup using small silica columns and thin-layer chromatography. A sensitive determination of 594 ng of steviol present in 100 mg of dry plant material was performed with high precision and accuracy.     

Monoclonal enzyme immunoassay for the analysis of carbaryl in fruits and vegetables without sample cleanup

The N-methylcarbamate pesticide carbaryl is one of the most important insecticides used worldwide. In the present work, the validation of a monoclonal antibody-based enzyme immunoassay (ELISA) for the determination of this compound in fruits and vegetables is described. The immunoassay is a competitive heterologous ELISA in the antibody-coated format, with an I(50) value for standards in buffer of 101.0 +/- 26.9 ng/L and with a dynamic range between 31.6 and 364.0 ng/L. For recovery studies, peppers, cucumbers, strawberries, tomatoes, potatoes, oranges, and apples were spiked with carbaryl at 10, 50, and 200 ppb. After liquid extraction, analyses were performed by ELISA on both extracts purified on solid-phase extraction (SPE) columns and crude, nonpurified extracts. Depending on the crop and the fortification level, recoveries in the 59.0--120.0% range were obtained for purified samples and in the 70.0--137.7% range for crude extracts. The carbaryl immunoassay performance was further validated with respect to high-performance liquid chromatography (HPLC) with postcolumn derivatization and fluorescence detection (EPA Method 531.1). Samples were spiked with carbaryl at several concentrations and analyzed as blind samples by ELISA and HPLC after SPE cleanup. The correlation between methods was excellent (y = 1.04x + 0.71, r(2) = 0.992, n = 33), with HPLC being more precise than ELISA (mean coefficients of variation of 5.2 and 12.0%, respectively). The immunoassay was then applied to the analysis of nonpurified extracts of the same samples. Results also compared very well with those obtained by HPLC on purified samples (y = 1.28x - 0.59, r(2) = 0.987, n = 33) while maintaining similar precision. Therefore, the developed immunoassay is a suitable method for the quantitative and reliable determination of carbaryl in fruits and vegetables even without sample cleanup, which saves time and money and considerably increases sample throughput.