Analyzing antibiotic residues in honey samples using liquid chromatography-tandem mass spectrometry.

This study aimed to present a sensitive, accurate, and precise analytical method for the determination of 32 antibiotics from 5 groups (sulfonamides, macrolides, aminoglycosides, tetracyclines, and quinolones) and some individual antibiotics (lincomycin, griseofulvin, and 5-hydroxy-flunixin) in 63 honey samples collected from Tehran market. In the presented method, the samples were hydrolyzed by 1% HFBA (hepta fluoro butyric acid) in water, purified on Strata XL polymeric reversed-phase cartridges, and finally analyzed by reversed-phase ion-pair liquid chromatography-electrospray ionization tandem mass spectrometry (RP-IP-LC-ESI-MS/MS). Good performance characteristics were gained for recovery, precision, range, and linearity, the limit of detections (LODs), and the limit of quantifications (LOQs). According to the presented results and considering the absence of permissible limits for antibiotics in honey, 74.6% of the tested samples had antibiotic residues more than the LOQ of the method. The results show that the validated method is suitable for simultaneously detecting antibiotic residues in honey.

Multivariate Optimization and Validation of a Modified QuEChERS Method for Determination of PAHs and PCBs in Grilled Meat by GC-MS.

Polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) are recognized as carcinogens and mutagenic food contaminants that threaten public health. As for food safety aspects, control of these contaminants in processed and fatty food is necessary. In this study, eleven factors were screened by the Plackett-Burman design, and four variables were chosen to optimize with the central composite design (CCD) for the improvement of extraction and cleanup procedures of these food contaminants. The optimized variables include 5 g of sample, 2 mL mixture of 2/2/1 ethyl acetate/acetone/isooctane, 1.6 g of ammonium formate, 0.9 g of sodium chloride, and 0.25 g of sorbent Z-Sep+. A 5 min cleanup vortex time with the spike calibration curve strategy, analyzed by gas chromatography-mass spectrometry (GC-MS), led to the validated limits of quantification (LOQs) for 16 PAHs and 36 PCBs of 0.5-2 and 0.5-1 ng/g, respectively, and recoveries of 72-120%, with an average relative standard deviation (%RSD) of 17, for PAHs, and 80-120%, with an %RSD of 3, for PCBs. The method introduces excellent accuracy, precision, and efficiency, and minimizes matrix effects, and ensures a control procedure, adopted with international standards, for food authorities to determine the contaminants of interest in processed meat, and consequently, prevent food-borne disease to improve public health indices.

Pesticide residues in dates using a modified QuEChERS method and GC-MS/MS.

The aim of this study was to develop a convenient, fast, effective and safe analytical method (QuEChERS) to determine 198 pesticide residues in multi-source date palm fruits using gas chromatography-tandem mass spectrometry (GC-MS/MS). The calibration curves for most pesticides were linear in the range of 15-150 µg/kg, with r2 values higher than 0.9934 and the relative standard deviation for all pesticides was ≤20%. The mean recovery rate of pesticides was 70-120% and limits of detection (LODs) and limits of quantification (LOQs) were in the range of 5-14 µg/kg and 14-40 µg/kg, respectively. The validated procedure was used to monitor pesticide residues in 30 fresh date samples. It could be concluded that the modified QuEChERS extraction method was efficient in analysing pesticide residues in dates palm and none of the samples contained residues above the MRLs.

Simultaneous Analysis and Efficient Separation of Anabolic Androgenic Steroids in Dietary Supplement by a Validated HPTLC Method.

Background: Using sports supplements is common among athletes. The presence of anabolic steroids in sports supplements as a hormonal contaminant can increase production efficiency. Since anabolic steroids cause health problems and result in positive doping tests in athletes, it is important to investigate their presence in the supplement preparations consumed by athletes. Objectives: This paper aims to simultaneously determine ten anabolic steroids by high-performance thin-layer chromatography (HPTLC) method in sports supplements. Methods: Chromatographic analysis was conducted on glass silica gel 60F254 plates. The extracts loaded on silica gel plates are subjected to programed multiple development (PMD) to separate anabolic androgenic steroids (AASs). Densitometric scanning is carried out at the wavelength of 245 and 366nm. The method was validated according to the ICH guidelines. Results: Spots at retardation factor (Rf) 0.72 (elution system 1), 0.4 (elution system 1), 0.29 (elution system 2), 0.25 (elution system 2), 0.1 (elution system 1), 0.65 (elution system 2), 0.59 (elution system 1), 0.44 (elution system 1), 0.8 (elution system 3), and 0.82 (elution system 3) values were recognized as 19-nor androstenedione, 19-nortestosterone, methyl testosterone, clostebol, stanozolol, trenbolone enanthate, oxymetholone, oxandrolone, testosterone enanthate, and nandrolone decanoate, respectively. The linear ranges were 25 - 250 µg/mL for oxymetholone, 7 - 50 µg/mL for 19-nor androstenedione, 19-nortestosterone, and oxandrolone, and 3 - 20 µg/mL for methyl testosterone, clostebol, stanozolol, trenbolone enanthate, testosterone enanthate, and nandrolone decanoate. The developed method is validated by acceptable precision (CV < 20%) and good accuracy (94% < R < 114%). The value of limit of detection (LOD) for all derivatives was in the range of 0.02 - 0.16 µg/spot (20-160 µg/g of supplement), while limit of quantitation (LOQ) was found to be in the range of 0.06 - 0.5 µg/spot (60 - 500 µg/g of supplement). Fifty sports supplement samples as real sample were collected and analyzed. None of the samples screened positive using the HPTLC method. Conclusions: In the present study, the fast, cheap, and simple HPTLC method could be used for the multi-residue analysis of ten anabolic androgenic steroids in sports supplements.

Comparison of near-infrared (NIR) and mid-infrared (MIR) spectroscopy based on chemometrics for saffron authentication and adulteration detection.

In this work, the potential of near-infrared (NIR) and mid-infrared (MIR) spectroscopy along with chemometrics was investigated for authentication and adulteration detection of Iranian saffron samples. First, authentication of one-hundred saffron samples was examined by principal component analysis (PCA). The results showed the NIR spectroscopy can better predict the origin of samples than the MIR. Next, partial least squares-discriminant analysis (PLS-DA) was developed to detect four common plant-derived adulterants (i.e., saffron style, calendula, safflower, and rubia). In all cases, PLS-DA classification figures of merit in terms of sensitivity, specificity, error rate and accuracy were satisfactory for both NIR and MIR datasets. The built models were then successfully validated using test set and also commercial samples. Finally, partial least squares regression (PLSR) was used to estimate the amount of adulteration. In this case, only NIR showed a good performance with regression coefficients (R2) in range of 0.95-0.99.

Survey of protein-based sport supplements for illegally added anabolic steroids methyltestosterone and 4-androstenedione by UPLC-MS/MS.

There is some evidence that marketable supplements contain hormones not declared on the product label. The presence of these androgenic anabolic steroids (AAS) in sports supplements can be considered an adulteration and affect the health of consumers, who are predominantly athletes. This study aimed to measure anabolic hormones (methyltestosterone and 4-androstenedione) in sport supplements. Ultra Performance Liquid chromatography coupled mass spectrometry (UPLC-MS/MS) with electrospray ionization (ESI) in positive mode was employed under the Multiple Reaction Monitoring (MRM) ion program. To overcome matrix effects and quantify the selected analyte, the calibration curve was made using Matrix Match method. The LOQ and LOD were 1 ng/g and 0.3 ng/g for both analytes. The recovery of 4-androstenedione and methyltestosterone was in the range of 86.87-107.35 and 77.31-113.98, respectively. In terms of reproducibility, CV % for 4-androstenedione and methyltestosterone ranged from 6.56 to 16.87% and 1.45-15.12%, respectively. 4-androstenedione was found in 11 samples including 9 whey as 1.578 ±â€¯0.154 ng/g and 2 whey albumin samples with an amount of 1.134 ng/g and 1.474 ng/g. Consequently, continuous controlling of sport supplements comprising intentionally or unintentionally added androgens could be important for health and discuss in the context of compliance with anti-doping.

Combining multivariate image analysis with high-performance thin-layer chromatography for development of a reliable tool for saffron authentication and adulteration detection.

In this work, high-performance thin-layer chromatography (HPTLC) coupled with multivariate image analysis (MIA) is proposed as a fast and reliable tool for authentication and adulteration detection of Iranian saffron samples based on their HPTLC fingerprints. At first, the secondary metabolites of saffron were extracted using ultrasonic-assisted solvent extraction (UASE) which was optimized using central composite design (CCD). Next, the RGB coordinates of HPTLC images were used for estimation of saffron origin based on principal component analysis (PCA). The PCA scores plot showed that saffron samples were clustered into two clear-cut groups which was 92% matched with the geographical origins of the samples. In the next step, common plant-derived adulterants of saffron including safflower, saffron style, calendula, and rubia were investigated with MIA analysis of HPTLC images using partial least squares-discriminant analysis (PLS-DA) at 5-35% (w/w) levels. The PLS-DA results showed proper classification of saffron and adulterants with sensitivity 99.14%, specificity 96.94%, error rate 1.96% and accuracy 98.04. Also, the effect of HPTLC injection volume on the performance of the proposed strategy was evaluated. The ability of the proposed method was then investigated by analyzing two additional sample sets including mixed samples of four plant-derived adulterants and adulterated commercial samples. Sensitivity and specificity of this model were 100% which confirmed its validity.

The concentration and probabilistic health risk assessment of pesticide residues in commercially available olive oils in Iran.

This study was undertaken to analyze 29 pesticides residues in 37 commercially olive oil collected samples from Iran's markets using Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) approach along with acetonitrile for the extraction, surface adsorbents for clean-up procedure, following with a gas chromatography-mass spectroscopy (GC-MS). In order to eliminate the matrix effect, the calibration curves were drawn using spiked samples with the Area under curve (AUC) portion calculation of pesticide residue to AUC internal standard (Triphenyl Methane (TPM)). Moreover, the probabilistic health risk assessment includes non-carcinogenic and carcinogenic risk were estimated by target hazard quotient (THQ), total target hazard quotient (TTHQ) and cancer risk (CR) using the Monte Carlo Simulation (MCS) method. The calibration curves were linear in the range of 10-1500 ng/g, and R2 was higher than 0.994. All pesticides recoveries as average were in the range of 77.97-112.65%. The respective numbers attributed to LOD and LOQ were 3-5 ng/g and 8-15 ng/g. Results showed that 29.7% of samples were contaminated by pesticides which according to Iranian regulation, while in 7 cases banned pesticides were detected. Only 4 samples are noncompliant with EU regulation. The rank order of pesticides based on THQ was Heptachlor > DDT > Pretilachlor. Also, TTHQ for adults was 0.139; and children 0.467. The rank order of pesticides based on CR was Heptachlor > DDT. Consumers (adults and children) are not at non-carcinogenic risk due to ingestion of oil olive content (THQ and TTHQ < 1 value) but are at considerable carcinogenic (CR > 1E-6). According to the observed profile of pesticide in olive oil samples, which are mostly banned according to Iranian regulation, further improvements in agriculture procedures of cultivated olive in Iran, as well as required assessments of imported olive oil, was recommended.

Probabilistic non-carcinogenic and carcinogenic risk assessments (Monte Carlo simulation method) of the measured acrylamide content in Tah-dig using QuEChERS extraction and UHPLC-MS/MS.

A modified "Quick, Easy, Cheap, Effective, Rugged, and Safe" QuEChERS in combination with Ultra-High Performance Liquid Chromatography/tandem mass spectrometry (UHPLC-MS/MS) method was optimized for the determination of acrylamide content in different types of tah-dig (rice, bread, and potato). Also, the non-carcinogenic and carcinogenic risks (target hazard quotient (THQ) and incremental lifetime cancer risk (ILCR)) due to ingestion of acrylamide via tah-dig in the adults and children were assessed by Monte Carlo simulation (MCS) method. The recoveries of acrylamide at five concentration levels (n = 3) ranged from 83.82% to 106.41%. The repeatability of the proposed method was demonstrated with RSD% in the range of 11.3-20%. In addition, the limits of detection and quantification were reported as 5 ngg-1 and 15 ngg-1, respectively. The mean levels of the acrylamide contents in rice tah-dig, bread tah-dig, and potato tah-dig were measured as 24.65 ngg-1, 39.48 ngg-1, and 714.11 ngg-1, respectively. The highest acrylamide content was determined in potato tah-dig (2100 ngg-1) and the lowest acrylamide in rice tah-dig (≤LOQ). Based on the conducted risk assessment, the P (95%) of cumulative probability in the MCS method, the lowest and highest THQ was observed in the adults (ingestion bread tah-dig: 1.29E-2), and children (ingestion potato tah-dig: 1.90E+00), respectively. Additionally, the lowest and highest ILCR were reported in adults (ingestion bread tah-dig: 1.29E-5) and children (ingestion potato tah-dig: 7.49E-3), respectively. The rank order of type tah-dig based on THQ and ILCR for all groups of consumers was potato tah-dig > rice tah-dig > bread tah-dig. There is a considerable non-carcinogenic risk for the children due to ingestion potato tah-dig (THQ > 1). Additionally, the significant carcinogenic risk for the Iranian adults and children due to consumption of rice, bread, and potato tah-dig (ILCR > 1.00E-5) was observed.

Exposure Assessment for Some Pesticides through Rice Consumption in Iran Using a Multiresidue Analysis by GC-MS.

In communities which consume rice as main food, importance of risk assessment for contaminants is always taken into consideration by health authorities. The present study is an attempt for monitoring of 56 pesticides from different chemical groups in rice samples collected from local markets in Tehran and estimation of daily intake of interested pesticides through this monitoring. A valid method based on spiked calibration curves and QuEChERS sample preparation was developed for determination of pesticides residue in rice by GC/MS. The analytical results of the proposed method were in good agreement with the proficiency test (FAPAS 0969). One-hundred-thirty-five rice samples were analyzed and 11 pesticide residues were found in 10.4% of the samples. Of which 5.2% were contaminated with unregulated pesticides. None of the samples, which were contaminated with regulated pesticides, had contamination higher than maximum residue limit. The mean estimated dose (ED) was calculated with respect of mean of contamination and mean daily consumption of rice. ED of the found pesticides is much lower than the related ADIs.

Comparison of risperidone and aripiprazole in the treatment of preschool children with disruptive behavior disorder and attention deficit-hyperactivity disorder: A randomized clinical trial.

Although pharmacotherapy with atypical antipsychotics is common in child psychiatry, there has been little research on this issue. To compare the efficacy and safety of risperidone and aripiprazole in the treatment of preschool children with disruptive behavior disorders comorbid with attention deficit-hyperactivity disorder (ADHD). Randomized clinical trial conducted in a university-affiliated child psychiatry clinic in southwest Iran. Forty 3-6-year-old children, diagnosed with oppositional defiant disorder comorbid with ADHD, were randomized to an 8-week trial of treatment with risperidone or aripiprazole (20 patients in each group). Assessment was performed by Conners' rating scale-revised and clinical global impressions scale, before treatment, and at weeks 2, 4, and 8 of treatment. The data were analyzed by SPSS version 16. Mean scores between the two groups were compared by analysis of variance and independent and paired t-test. Mean scores of Conners rating scales were not different between two groups in any steps of evaluation. Both groups had significantly reduced scores in week 2 of treatment (P = 0.00), with no significant change in subsequent measurements. Rates of improvement, mean increase in weight (P = 0.894), and mean change in fasting blood sugar (P = 0.671) were not significantly different between two groups. Mean serum prolactin showed a significant increase in risperidone group (P = 0.00). Both risperidone and aripiprazole were equally effective in reducing symptoms of ADHD and oppositional defiant disorder, and relatively safe, but high rates of side effects suggest the cautious use of these drugs in children.

A Multi Residue GC-MS Method for Determination of 12 Pesticides in Cucumber.

Cucumber is one of the main vegetables in Iranian food basket. A wide range of pesticides are used for crops protection during the cultivation of vegetables such as cucumber due to heavy pest infestation. Analysis of pesticide residues in food and other environmental commodities have become essential requirement for consumers, producers, and food quality control authorities. This study was aimed at determination of pesticides residues in cucumber as a main vegetable in Iranian food basket. A reliable, rapid and accurate method based on spiked calibration curves and modified QuEChERS sample preparation was developed for determination of 12 pesticide residues in cucumber by gas chromatography-mass spectrometry (GC/MS). The use of spiked calibration standards for constructing the calibration curve substantially reduced adverse matrix-related effects. The recovery of pesticides at 5 concentration levels (n = 3) was in the range of 80.6-112.3. The method was proved to be repeatable with RSD lower than 20%. The limits of detection and quantification for all pesticides were <10 ng/g and <25 ng/g, respectively. The developed method was used for simultaneous determination of the selected pesticides in 60 greenhouse and garden cucumber samples. Among the 60 analyzed samples, 41.7% of them were contaminated with pesticide residues which 31.7% of samples had pesticide residues lower than maximum residue limit and 10% of samples had residue higher than maximum residue limit.

Simultaneous Determination of 17 Pesticide Residues in Rice by GC/MS using a Direct Sample Introduction Procedure and Spiked Calibration Curves.

A reliable, rapid and accurate method based on spiked calibration curves and direct sample introduction was developed for determination of 17 pesticide residues in rice by gas chromatography-mass spectrometry single quadrupole selected ion monitoring GC/MS-SQ-SIM. Sample preparation is based on extraction with acetonitrile without clean up. The use of spiked calibration curves for constructing the calibration curve substantially reduced adverse matrix-related effects. The average recovery of pesticides at 6 concentration levels was in range of 97.5-102.1%. The method was proved to be repeatable with RSDr in range of 0.7%-19.8%for all of the concentration levels. The limits of detection and limit of quantifications for all the pesticides were < 10 ng/g and < 25 ng/g, respectively. The developed method was applied for simultaneous determination of the selected pesticides in 23 rice samples collected from Tehran retail market in March 2009. Although many studies have been conducted regarding the determination of pesticides by using GC-MS, this is the first attempt in Iran using GC-MS-SIM technique that successfully can determine 17 pesticides with difference in physicochemical properties in rice.

An applicable strategy for improvement recovery in simultaneous analysis of 20 pesticides residue in tea.

It is important to have a reliable method to analyze pesticides in tea, a beverage commonly consumed in Iran. A validated method was developed for the determination of 20 pesticides in tea based on QuEChERS sample preparation and capillary gas chromatography-quadrupole mass spectrometry in selective ion monitoring mode (GC-MS/SIM) using triphenyl methane (TPM) solution as an internal standard. We used fortified, extracted, and cleaned-up tea samples instead of calibration standards for quantitation, which substantially reduced adverse matrix-related effects and negative recovery affected by graphite carbon black (GCB) on pesticide analysis. The recovery of pesticides at 3 concentration (40, 60, and 240 ng/g) ranged from 79.5% to 111.4% (n = 3). The method had acceptable repeatability with RSDr < 20%. The limits of quantification (LOQ) for all pesticides were ≤20 ng/g. The analytical results of the proposed method were in good agreement with proficiency test results (FAPAS, 19116). The recoveries and repeatabilities were in accordance with the criteria set by SANCO Guideline. The validated method was suitable for the analysis of pesticides in tea.

Monitoring of some pesticides residue in consumed tea in Tehran market.

Tea is an agricultural product of the leaves, leaf buds, and internodes of various cultivars and sub-varieties of the Camellia sinensis plant, processed and vulcanized using various methods. Tea is a main beverage in Iranian food basket so should be free from toxic elements such as pesticides residue. There is no data bank on the residue of pesticides in the consumed black tea in Iran. The present study is the first attempt for monitoring of 25 pesticide residues from different chemical groups in tea samples obtained from local markets in Tehran, I.R. Iran during the period 2011. A reliable and accurate method based on spiked calibration curve and QuEChERS sample preparation was developed for determination of pesticide residues in tea by gas chromatography-mass spectrometry (GC/MS). The using of spiked calibration standards for constructing the calibration curve substantially reduced adverse matrix-related effects and negative recovery affected by GCB on pesticides. The recovery of pesticides at 3 concentration levels (n = 3) was in range of 81.4 - 99.4%. The method was proved to be repeatable with RSDr lower than 20%. The limits of quantification for all pesticides were ≤20 ng/g. 53 samples from 17 imported and manufactured brand were analyzed. Detectable pesticides residues were found in 28.3% (15 samples) of the samples. All of the positive samples were contaminated with unregulated pesticides (Endosulfan Sulfate or Bifenthrin) which are established by ISIRI. None of the samples had contamination higher than maximum residue limit set by EU and India.

Effect of cooking process on the residues of three carbamate pesticides in rice.

A gas chromatography mass spectrometry with spike calibration curve method was used to quantify three carbamate pesticides residue in cooked white rice and to estimate the reduction percentage of the cooking process duration. The selected pesticides are three carbamate pesticides including carbaryl and pirimicarb that their MRL is issued by "The Institute of Standards of Iran" and propoxur which is used as a widely consumed pesticide in rice. THE ANALYTICAL METHOD ENTAILED THE FOLLOWING STEPS: 1- Blending 15 g cooked sample with 120 mL acetonitrile for 1 min in solvent proof blender, 2- Adding 6 g NaCl and blending for 1 min, 3- Filtering upper layer through 25 g anhydrous Na2SO4, 4- Cleaning up with PSA and MgSO4, 5- Centrifuging for 7 min, 6- Evaporating about 0.3 mL and reconstituting in toluene till 1 mL, 7- Injecting 2 µL extract into GC/MS and analyzing by single quadruple selected ion monitoring GC/MS-SQ-SIM. The concentration of pesticides and the percentage of pesticides amounts after the cooking were determined by gas chromatography mass-spectrometry (GC/MS) using with interpolation of the relative peak areas for each pesticide to internal standard peak area in the sample on the spiked calibration curve. Calibration curve was linear over the range of 25 to 1000 ng/g, and LOQ was 25 ng/g for all three pesticides. The percent of loss for the three pesticides were 78%, 55% and 35% for carbaryl, propoxur and pirimicarb respectively. Different parameters such as vapor pressure, boiling point, and suspect ability of the compound to hydrolysis, could be responsible for the losing of pesticides during the cooking process.