Ionic Liquid-Based Dispersive Liquid–Liquid Microextraction Following High-Performance Liquid Chromatography for the Determination of Fungicides in Fruit Juices

This paper described an ionic liquid-based dispersive liquid–liquid microextraction (IL-DLLME) combined with high-performance liquid chromatography (HPLC) method to determine fungicides in fruit juices. In this method, 1-hexyl-3-methyli-midazolium hexafluorophosphate (HMIMPF₆) was used as extraction solvent, which dispersed into the fruit juices under vigorously shaking with the vortex. The effects of experimental parameters, such as extraction solvent volume, disperser solvent and its volume, vortex time, centrifugation time, sample pH, on the extraction efficiency were investigated. Under the optimum conditions, the linear correlation coefficients ranged from 0.9902 to 0.9979 for concentration levels of 0.02–2 mg l^?1, the extraction recoveries were ranged 66.2–92.9 % except pyrimethanil (39.5–44.6 %), The relative standard deviations (RSDs; n?=?6) ranged from 2.2 % to 11.6 %, and the limits of detection (LODs) for the fungicides were between 3.1 and 10.2 μg l^?1. Two real samples including apple and grape juices, spiked at two concentration levels were analyzed and yielded recoveries ranging from 71.3–93.1 % and 65.4–87.7 %, respectively.     

Detection of ochratoxin A in tropical wine and grape juice from Brazil

BACKGROUND: Ochratoxin A (OTA) is the main mycotoxin found in grapes, wines and grape juices and is considered one of the most harmful contaminants to human health. In this study, samples of tropical wines and grape juices from different grape varieties grown in Brazil were analysed for their OTA content by high‐performance liquid chromatography. RESULTS: The detection and quantification limits for OTA were 0.01 and 0.03 µg L^?1 respectively. OTA was detected in 13 (38.24%) of the samples analysed, with concentrations ranging from < 0.03 to 0.62 µg L^?1. OTA was not detected in any of the grape juice samples. Most of the red wine samples proved to be contaminated with OTA (75%), while only one white wine sample was contaminated. However, the OTA levels detected in all samples were well below the maximum tolerable limit (2 µg L^?1) in wine and grape juice established by the European Community and Brazilian legislature. CONCLUSION: The results of this study indicate a low risk of exposure to OTA by consumption of tropical wines and grape juices from Brazil. © 2012 Society of Chemical Industry     

Phytochemical Polyphenol Extraction and Elemental Composition of Vitis labrusca L. Grape Juices Through Optimization of Pectinolytic Activity

Grape juice is a natural source of polyphenols with potential health benefits. The aim of this study was to assess the optimized basis of the pectinolytic activity through a multivariate design for the bioactive enrichment of polyphenols in grape juices and to evaluate the effect of pectinases on the extraction of minerals by ICP-MS and FAAS. Grape juices were treated with pectinases Everzym® Color and Rapidase® Smart at different conditions of enzyme concentration (0.16–1.84 g L^?1), temperature (14.8–83.6?ºC), and incubation time (9.6–110.5 min), and the effect on total phenolics, anthocyanin content, and antioxidant activity of juices were determined by employing a second-order central composite design in combination with response surface methodology. The different conditions showed significant variations in polyphenol levels of grape juices. For both of the enzymes, the increase of temperature and enzyme concentration led to a higher extraction of polyphenols, with a significant effect. Estimated effects depict a good correlation among dependent variables. For Rapidase, the optimized extraction of polyphenols was determined at an enzyme concentration of 1.57 g L^?1 and at a temperature of 54.8?ºC. For Everzym, higher concentrations of polyphenols were obtained at the enzyme concentration of 1.30 g L^?1 at 46.8?ºC. The extraction using the Rapidase enzyme significantly increased the levels of Na, K, Mg, and Fe in grape juices (p?<?0.05). The pectinolytic activity increased the polyphenol and mineral concentrations in grape juices. In addition, the optimal conditions of the pectinolytic treatment comprise a feasible alternative to improve the bioactive potential of grape juices.     

Dispersive Liquid–Liquid Microextraction Followed by Capillary High-Performance Liquid Chromatography for the Determination of Six Sulfonylurea Herbicides in Fruit Juices

In this study a simple, rapid, and efficient method has been developed for the determination of six sulfonylurea herbicides (SUHs): triasulfuron, metsulfuron-methyl, chlorsulfuron, flazasulfuron, chlorimuron-ethyl, and primisulfuron-methyl in commercial grape and apple juice samples, using dispersive liquid–liquid microextraction coupled with capillary high-performance liquid chromatography with diode array detection. Various parameters that influence the extraction efficiency, such as the type and volume of extraction and disperser solvents, sample pH, and salt addition, were investigated and optimized. Under the optimum conditions, limits of detection and quantification of the method were in the ranges of 2–9 and 8–29 μg L^?1, respectively, lower than the maximum residue limits set by the European Union for the raw fruits, such as grape and apple. The intra- and inter-day relative standard deviations varied from 1.0 to 8.2 and 1.8 to 9.8 %, respectively, with recoveries between 72.0 and 109.5 % for commercial grape (both white and red) and apple juice samples, showing satisfactory accuracy for the determination of SUHs in fruit juices.     

Determination of Chlorantraniliprole Residues in Grape by High-Performance Liquid Chromatography

An effective analytical method for the residue analysis of a novel insecticide chlorantraniliprole and its dissipation in grape were studied. Chlorantraniliprole residues were extracted from grape samples with ethyl acetate. The extract was cleaned up with QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) method and determined by high-performance liquid chromatography with photodiode array detector (HPLC-DAD). At fortification levels of 0.06, 0.5, and 1.0 mg kg^?1 in grape, it was shown that recoveries ranged from 95.11 to 102 % with relative standard deviation (RSD) of 6 to 11 %. The limit of detection (LOD) and limit of quantification (LOQ) were found to be 0.02 and 0.06 mg kg^?1, respectively. The dissipation half-life time of chlorantraniliprole residues in grape was 2.70 days. According to maximum residue limit (MRL), the preharvest interval (PHI) of chlorantraniliprole on grape was 4 days after the treatment. Based on the results of this study and the relevant residue regulation, chlorantraniliprole residue levels will be acceptable when applied to grape in Egypt.     

高效液相色谱-荧光法同时检测葡萄汁中3 种苯并咪唑类农药

建立同时检测葡萄汁中3 种苯并咪唑类农药（多菌灵、噻菌灵、麦穗宁）残留的分散固相萃取处理结合高效液相色谱方法。样品经乙腈提取,无水MgSO4和NaCl盐析后,用N-丙基乙二胺固相萃取材料分散净化,然后采用高效液相色谱-荧光检测器根据不同的保留时间选择相应的最佳检测波长同时测定3 种农药。通过对提取盐、净化剂、色谱条件的优化,方法的加标回收率在85%～115%之间,相对标准偏差在1.95%～9.75%之间,多菌灵、噻菌灵和麦穗宁检出限分别达到17.60、1.20、0.06 μg/L。该方法简单、准确、重复性良好,满足葡萄汁中多种苯并咪唑类农药残留同时分析的需求。     

Determination of Triazole Fungicides in Liquid Samples Using Ultrasound-Assisted Emulsification Microextraction with Solidification of Floating Organic Droplet Followed by High-Performance Liquid Chromatography

An ultrasound-assisted emulsification microextraction with solidification of organic droplet method followed by high-performance liquid chromatography with diode array detection for six triazole fungicide determination (diniconazole, fluquinconazole, flusilazole, myclobutanil, tebuconazole, and tetraconazole) was developed. After some preliminary experiments, undecanol was chosen as extracting solvent using 50 μL for 10 mL of liquid sample. A central composite design was performed to obtain the best experimental conditions for the following variables NaCl concentration (250 g L^?1), extraction time (18 min), and temperature (30 °C) in ultrasonic bath. After the ultrasound-assisted extraction, two steps considering centrifugation (4,200 rpm, 10 min) and solidification (5 min, 3 °C) were done. Following these conditions, the method showed linearity higher than 0.9930 with the concentration ranged from 20 to 890 μg L^?1. The limits of detection obtained using calibration curves were from 10.9 to 17.2 μg L^?1 and the intra- and inter-day repeatability at two levels showed RSD values between 1.9 and 10.6 %. The enrichment factors for the studied triazoles were between 226 (flusilazole) and 255 (tebuconazole). Recovery studies at two spiked levels in apple and grape juices gave values from 64 to 112 %.     

Determination of multi-class pesticide residue in dietary supplements from grape seed extracts by ultra-high-performance liquid chromatography coupled to triple quadrupole mass spectrometry

A new method was developed and validated for the determination of multi-class pesticide residues in nutraceutical products obtained from grape seed extracts. The extraction procedure was based on QuEChERS methodology using ethyl acetate as solvent and a dispersive solid-phase extraction (dSPE) clean-up stage with C₁₈ was included to minimise matrix effects. Pesticides determination was achieved using ultra-high-performance liquid chromatography coupled to triple quadrupole mass spectrometry (UHPLC-QqQ-MS/MS); total running time was 11 min. Pesticides were quantified using matrix-matched calibration. The developed method was validated in terms of matrix effect, linearity, selectivity, limits of detection and quantification, trueness, repeatability and inter-day precision at three concentration levels (10, 50, 100 µg kg^?1). Suitable recovery values were obtained for 76% of analysed pesticides at the lowest concentration (10 µg kg^?1). For most of the compounds, relative standard deviation values were lower than 20% and 25% for intra- and inter-day precision, respectively. Finally, 106 pesticides were determined, and the method was applied to seven dietary supplements from grape seed extract, obtaining various positive results for piperonyl butoxide, cyromazine and diniconazole at concentrations ranging from 2.0 to 13.4 µg kg^?1.     

温控辅助离子液体分散液液微萃取-高效液相色谱检测果汁中杀菌剂残留

建立温控辅助离子液体分散液液微萃取结合高效液相色谱-二极管阵列检测器法检测果汁中7 种杀菌剂农药残留的新方法。对影响萃取效果的因素萃取剂和分散剂类型及体积、溶解温度、萃取时间和离心时间进行优化。在优化后的方法条件下,7 种杀菌剂富集倍数可达64～101;方法检出限在4.3～13.0 μg/L之间;在0.02、0.05 mg/L和0.10 mg/L三个水平下加标,果汁（苹果汁、梨汁、葡萄汁、桃汁和橙汁）的平均加标回收率在70.0%～116.2%范围内,相对标准偏差均小于9.8%,能满足多种果汁中杀菌剂农药多残留检测的要求。     

Determination of Trans-resveratrol in Wines,Spirits, and Grape Juices Using Solid-Phase Micro Extraction Coupled to Liquid Chromatography with UV Diode-Array Detection

Solid phase microextraction (polyacrylate fiber), coupled to liquid chromatography with UV diode-array detection, has been optimized for the determination of trans-resveratrol in wines, spirits, and grape juices. The main aspects influencing fiber adsorption (fiber coating, extraction time, ethanol content, salt addition) and desorption (desorption and injection time, desorption solvent mixture composition, carryover) of the analyte have been investigated. The method permitted a fast and simple determination of free trans-resveratrol in commercial samples. It was found in all the analyzed samples at concentration levels ranging from 0.007 to 4.486 μg mL^?1. Total trans-resveratrol concentrations were also evaluated after enzymatic deconjugation of piceid.     

Use of Factorial Design in the Development of Multiresidue Method for Determination of Pesticide Residues in Wheat by Liquid Chromatography-Tandem Mass Spectrometry

The evaluation of analytical methods for determining the level of residues and contaminants in food samples is a continuing need. To improve this evaluation, it is necessary to investigate different extraction procedures and conditions. A 2³ factorial design was applied to establish an analytical method for determining pesticide residues in wheat by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Factors that influence the recovery of compounds, such as agitation and different processes of partition and cleanup, were investigated. Extracts were analyzed by LC-MS/MS with electrospray ionization in a triple quadrupole system. The use of ultrasonic agitation in the extraction step, deep freezing for the partition step, and C18 cleanup provided significantly better recoveries for most of the compounds evaluated. Assessment of each factor as well as interactions between factors allowed for a more effective evaluation of the parameters involved in the development of analytical methods. The validation results were satisfactory, since the method presented linearity (r ²) >0.99 for all compounds, the matrix effect ranged from 3 to 97 % and was corrected by matrix-matched standards, and recoveries ranged from 70 to 120 % with RSD ≤20 % for the spike levels of 10 and 100 μg kg^?1. The method limit of detection and limit of quantification ranged from 3.3 to 6.7 μg kg^?1 and from 10 to 20 μg kg^?1, respectively, and the expanded uncertainty ranged from 15 to 32 %. The proposed method met the criteria for determination of 42 pesticides in wheat samples and was successfully tested in real samples.     

Graphene Reinforced Hollow Fiber Liquid-Phase Microextraction Combined with HPLC for the Determination of Bisphenol A and 4-Tert-Butylphenol in Bottled Juice

A new analytical method by graphene-reinforced hollow fiber liquid-phase microextraction combined with high-performance liquid chromatography fluorescence detection was developed for the determination of bisphenol A and 4-tert-butylphenol in bottled juices. Several important experimental parameters were studied to get optimal extraction conditions for the analytes. Under the optimized conditions, the method showed a good performance having a linear response in the range from 0.05 to 10.0 ng mL^?1 with the correlation coefficients (r) of 0.9965–0.9994 and limits of detection of 0.01 ng mL^?1. The relative standard deviations were in the range from 6.4 to 7.2 % at the spiked concentration of 1.0 ng mL^?1. The method combines the high-adsorption capacity of graphene and the excellent clean-up performance of hollow fiber liquid-phase microextraction and has been successfully applied to the analysis of the analytes in bottled juice samples.     

Rapid estimation and quantification of sucrose content in fruit juices using Fourier transform infrared–attenuated total reflectance (FTIR–ATR) spectroscopy

An uncomplicated and rapid procedure has been developed for the quantitative analysis of sucrose in fruit samples (grape, pineapple, mango) through attenuated total reflectance–Fourier transform infrared absorbance measurements (ATR–FTIR). FTIR analysis takes considerably reduced time compared to the other classical methods. To calibrate the method, we used firstly, different concentrations of pure sucrose (from 1 to 5 %) and registered their IR maximal wavenumbers and peak intensity. The spectral peak of sucrose for each sample lies between 1057 and 1061 cm^?1. DNS method was used to analyse the content of sucrose by using spectrophotometry. The wave length used for analysing is 540 nm. Also high performance liquid chromatography was used to analyse the sucrose content in the fruit juices. By comparing the retention time of sucrose standards and the sample juices, sucrose concentration was identified and quantified. The results of all three experiments/techniques support each other by justifying that the mango has the high content of sucrose followed by pineapple and grape.     

Hydroxymethylfurfural in fruit puree and juice: preconcentration and determination using microextraction method coupled with high-performance liquid chromatography and optimization by Box–Behnken design

In the present study, a sensitive and rapid method for separation and determination of hydroxymethylfurfural (HMF) in fruit puree and juices was proposed. Dispersive liquid–liquid microextraction (DLLME) coupled with high-performance liquid chromatography (HPLC) was used for extraction and quantitative determination of HMF in fruit puree and juices. The effective parameters such as the type and volume of extraction and dispersive solvents, pH and salt amount (NaCl) were studied and optimized with the aid of response surface methodology based on Box–Behnken design to obtain the best condition for HMF extraction. At the optimized conditions, parameter values were 60 µL extracting solvent, 600 µL dispersive solvent, 2 g NaCl and pH 5. Repeatability of the method, described as the relative standard deviation, was 3.1% (n?=?6) and the recovery was 98.4%. The limit of detection and limit of quantitation were 1.47 and 5.28 µg L^?1, respectively. The merit figures of DLLME–HPLC–UV method showed that the proposed method can be noticed as a new, fast and good alternative method for investigation of HMF in various fruit puree and juice samples.     

Development of Salt-Induced Homogenous Liquid–Liquid Microextraction Based on <Emphasis Type="Italic">iso</Emphasis>-Propanol/Sodium Sulfate System for Extraction of Some Pesticides in Fruit Juices

In the present work, a simple and fast sample pretreatment method based on salt-induced homogenous liquid–liquid microextraction has been proposed for the extraction and preconcentration of some widely used pesticides (diazinon, ametryn, chlorpyrifos, penconazole, oxadiazon, diniconazole, and fenazaquin) from different fruit juice samples prior to gas chromatography-flame ionization detection. Initially, a small volume (microliter level) of an extraction solvent (iso-propanol) is added into an aqueous phase containing the analytes in order to obtain a homogenous solution. Then, a phase separation agent (sodium sulfate) is added into the homogeneous solution. By this action, the extraction solvent releases from the homogenous solution in the form of tiny droplets containing the analytes and collects on the surface of the aqueous phase as a thin film. A home-made device is used to simplify the removal of the collected organic phase. Finally, an aliquot of the collected organic phase is removed and injected into the separation system for analysis. Under the optimum conditions, limits of detection and quantification were obtained at the ranges of 0.22–0.48 and 0.73–1.7 μg L^?1, respectively. The enrichment factors and extraction recoveries of the selected pesticides ranged from 410 to 480 and 82 to 96%, respectively. The relative standard deviations were ≤?7% for intra- (n?=?6) and inter-day (n?=?4) precisions at a concentration of 10 μg L^?1 of each analyte. Finally, the proposed procedure was successfully applied to the analysis of real samples including apple, sour cherry, peach, grape, and orange juices in order to simultaneously determine the seven aforementioned pesticides. The proposed approach is simple, sensitive, rapid, and requires low solvent consumption, which, in the era of green chemistry, represents a significant advantage. This method and the obtained results can contribute in the improvement of food quality as well as monitoring level of pesticide usage in fruit juices.     

Determination of Arsenic in Fruit Juices Using <Emphasis>I</Emphasis>nductively Coupled Plasma Tandem Mass Spectrometry <Emphasis>(ICP-MS/MS)</Emphasis>

Reports from the US media have raised the attention towards a possible contamination of apple juices by As. The study here described presents the development of an analytical procedure using inductively coupled plasma tandem mass spectrometry (ICP-MS/MS) for determination of As in apple and orange juices commercialized in the Tetra Pack^® package. The microwave-assisted acid digestion of juice was carried out using closed vessels and 2 mol/L HNO₃ plus H₂O₂. These conditions are favorable for a better analytical blank control. Suitable recoveries were reached when promoting reaction with O₂ inside the octopole reaction system (ORS³), and the monitoring of ⁷⁵As¹⁶O⁺ significantly improved the accuracy of the analysis reaching a limit of detection of 0.013 μg/L. Recoveries varied from 88 to 109 % in the MS/MS mass-shift mode. The As concentrations determined in fruit juices ranged from 0.126 to 1.45 μg/L, and they were significantly lower than the maximum tolerable limits imposed by the US and Brazilian legislations. Thus, ICP-MS/MS operated in the reaction mode was an effective instrumental strategy for overcoming spectral interferences, such as ⁴⁰Ar³⁵Cl⁺, in As determination as ⁷⁵As¹⁶O⁺ and allowed the accurate determination of As at trace levels.     

Antioxidant activities of fresh grape juices prepared using various household processing methods

The purpose of this study was to evaluate and compare the antioxidant activities, and their contents, in grape juices prepared by various household juicers, and grape flesh (GF). The grape juices were prepared using a low-speed masticating (LSM) juicer, a high-speed centrifugal (HSC) juicer, and a blender (BLD). The total polyphenol, total flavonoid, total monomeric anthocyanin, and vitamin C contents were highest in the LSM grape juice, and decreased in the order: LSM > BLD > HSC > GF. The antioxidant activities such as DPPH radical scavenging activity, and SOD-like activity were significantly higher in the LSM juice than in other juices and grape flesh. The antioxidant activities and the quality of grape juices were significantly affected by the household juicing method used, and an LSM juicer is strongly recommended for making healthy grape juice, rich in antioxidants.     

Oxytetracycline,tetracycline, chlortetracycline and doxycycline in pasteurised cow’s milk commercialised in Brazil

The aim of this study was to investigate the presence of tetracycline residues in pasteurised cow’s milk using high-performance liquid chromatography coupled with UV/VIS detection to determine the exposure of Brazilian’s population to antibiotic residues. One hundred samples collected from the State of Paraná, Brazil, were analysed. Three of these samples were contaminated at the following concentrations: 121.8 µg·kg^?1 for oxytetracycline, 93.5 µg·kg^?1 for tetracycline and 134.6 µg·kg^?1 for chlortetracycline (61.6 µg·kg^?1) and doxycycline (73.0 µg·kg^?1). The median tetracycline residue concentration found in the samples was 42.3 µg·kg^?1, and the estimated daily intake (EDI) was 0.05 µg Kg^?1 bw day^?1 in Brazil. These results demonstrate that the occurrence of tetracycline in Brazilian milk was low (3%) and only for 2% above the maximum residue limit, so the risk to the population from the presence of these residues in milk was low (<1% of the acceptable daily intake).     

Vortex-Assisted Ionic Liquid Dispersive Liquid-Liquid Microextraction Coupled with High-Performance Liquid Chromatography for the Determination of Triazole Fungicides in Fruit Juices

A rapid, efficient, and environmentally friendly method using vortex-assisted ionic liquid dispersive liquid-liquid microextraction (VA-IL-DLLME) prior to high-performance liquid chromatography coupled with photodiode array detection (HPLC-PDA) has been developed for the determination of six triazole fungicides (triazolone, triadimenol, epoxiconazole, flusilazole, tebuconazole, and diniconazole) in various fruit juices. 1-Hexyl-3-methylimidazolium hexafluorophosphate ([C₆MIM][PF₆]) and acetonitrile were used as extraction and dispersive solvents, respectively. A single factor experiment was selected to obtain the significant variables from the several related parameters that could affect the extraction efficiencies, such as the volume of IL and acetonitrile, extraction time, centrifugation time, and salt addition. Under the optimum conditions, an excellent linearity with correlation coefficients higher than 0.997 was obtained. Enrichment factors and average recoveries in three concentration levels ranged from 51 to 72, and 71.0 to 104.5 %, respectively, and the relative standard deviations (RSDs) from 1.4 to 11.8 %. The limits of detection (LODs) (S/N?=?3) for the six triazole fungicides were between 0.4 and 6.7 μg L^?1. The proposed method was successfully applied for the determination of trace amounts of triazole fungicides in various fruit juices including peach, apple, and orange juices.     

Simultaneous determination of neonicotinoid insecticides in sunflower-treated seeds (hull and kernel) by LC-MS/MS

A validated analytical method to determine seven neonicotinoids (dinotefuran, nitenpyram, thiamethoxam, clothianidin, imidacloprid, acetamiprid and thiacloprid) in sunflower seeds (hull and kernel) using HPLC coupled to electrospray ionisation mass spectrometry (ESI-MS) is presented. Sample clean-up based on a solid–liquid extraction, and the removal of lipid fraction, in the case of kernels, is proposed and optimised. Low limits of detection and quantification were obtained, ranging from 0.3 × 10^–3 to 1.2 × 10^–3 µg g^–1 and from 1.0 × 10^–3 to 4.0 × 10^–3 µg g^–1, with good precision, and recovery values ranged from 90% to 104% for hulls and kernels. The method was applied for the analysis of five thiamethoxam-dressed sunflower seeds and four non-treated seeds, where, besides thiamethoxam, residues of the other neonicotinoid, clothianidin, were also detected and confirmed via tandem mass spectrometry (LC-ESI-MS/MS). Finally, the presence of residues of thiamethoxam and clothianidin in collected sunflower seeds (hulls) coming from coated seeds confirmed the translocation of these neonicotinoids through the plant up to these seeds.