Matrix solid-phase dispersion as a valuable tool for extracting contaminants from foodstuffs

Simultaneous Determination of Multiple Contaminants in Chicken Liver Using Dispersive Liquid-Liquid Microextraction (DLLME) Detected by LC-HRMS/MS

Simultaneous determination of a mixture of food contaminants, including pesticides, sulphonamides, fluoroquinolones, anthelmintics, and aflatoxin B1, in solid biological samples (chicken liver) by dispersive liquid-liquid microextraction/liquid chromatography-high resolution mass spectrometry (DLLME/LC-HRMS) is presented. Previous work focused on the application of DLLME to single-class contaminants. In this work, the DLLME extraction method has been extended to complex multiresidues in the biological matrix. The first part of this study was the selection of an appropriate solvent that enabled the dissolution of analytes from the chicken livers. The matrix-matched calibration curves showed good linearity in the range 0.5-50.0 µg kg^-1 for aflatoxin B1 and 50-500 µg kg^-1 for pesticides, fluoroquinolones, sulphonamides, and anthelmintics, with a coefficient of determination (R²) values of 0.9916-0.9967. The mean recoveries were in the range of 80.4-96.3%, and the relative standard deviation (RSD) values were in the range of 1.53-8.98%. The limit of detection (LOD) and the limit of quantification (LOQ) values were 0.03 µg kg^-1 and 0.09 µg kg^-1, respectively, for aflatoxin B1, and for pesticides, fluoroquinolones, sulphonamides, and anthelmintics, they were in the range of 0.011-1.197 µg kg^-1 and 0.150-2.579 µg kg^-1, respectively. The developed method was compared with the standard solid phase extraction (SPE) method, and there was no significant difference between the two methods.

A Review on Recent Innovations of Pretreatment and Analysis Methods for Sulfonylurea Herbicides

Sulfonylurea herbicides (SUHs) are widely used in agriculture because of their low dosage, low cost, and high selectivity. However, due to improper use and lack of effective management, their residues pose a threat to the human health through environment and food pollution. Therefore, there is a need for simple, quick, economical, and effective methods to analyze SUHs in plant-derived foods, crops, and environmental samples. The present article presents a comprehensive review of the pretreatment and analytical technologies used for SUHs in various sample matrices, focusing on the developments since 2010. The main pretreatment methods include liquid-liquid extraction, solid-phase extraction, QuEChERS, and different microextraction methods, whereas analytical methods mainly include liquid chromatography coupled with different detectors, capillary electrophoresis, among others. In addition, the present study also compared the advantages and disadvantages of the methods and the future development is prospected.

Evaluation of pesticide residues and risk assessment in apple and grape from western Azerbaijan Province of Iran

West Azerbaijan, especially the city of Urmia, is the center of Iranian apple and grape production hence the importance of this, residues of 85 pesticides in these products were investigated using modified QuEChERS extraction followed by UHPLC-MS/MS technique. Residues of 17 different pesticides detected in some apple samples. In grape sample only 7 pesticides detected. The levels of the residues found in all apple and grape samples were below the maximum residue levels (MRLs) of Iran, except for iprodione. Health risk assessment associated with pesticide residues in apples and grapes were estimated by hazard quotient (HQ) and hazard index (HI), which indicated that the HI value was lower than 1 in adults and children due to apple and consumption. HI in adults and children were 0.012 and 0.054 in apple; 0.001 and 0.003 in grape samples, respectively. Although the health risk assessment showed that the consumers are not at considerable risk but due to pesticide residue, implement control plans to manage the proper application of this pesticide, or replace it with safer alternatives in apple and grape is required.

Fe3O4 nanoparticles as matrix solid-phase dispersion extraction adsorbents for the analysis of thirty pesticides in vegetables by ultrahigh-performance liquid chromatography-tandem mass spectrometry

Herein we report the first example of Fe₃O₄ nanoparticles (FNPs) being used as single-matrix solid-phase dispersion (MSPD) adsorbents for the extraction of 30 representative pesticides from vegetables. This study was aimed at analyzing the extracted samples using ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Various condition parameters, such as the eluent, volume of the eluent, and amount of FNPs were optimized to achieve good sensitivity and precision for the elution and extraction of the analytes. The developed method was validated using matrices consisting of eight vegetables (lettuce, cucumber, carrot, tomato, pepper, shallot, Chinese flowering cabbage, and cabbage) spiked with 30 pesticides at concentrations of 0.01, 0.1, and 1.0 mg/kg. The recoveries of the 30 pesticides (organophosphorus, triazole, carbamate, nicotine, amide, and other different structures of pesticides) were in the range 71.0-110.8% (n = 5) (except those of prothioconazole and dinotefuran), with relative standard deviations lower than 13.5% in all the matrices under optimal conditions. The matrix effects were observed by comparing the slope of the matrix-matched standard calibration curve with that of the solvent. However, the matrix effects of the eight vegetables did not show evident regularities. For pepper, tomato, and shallot, a sizable number of pesticides (24, 21, and 21, respectively) showed suppressive matrix effects. On the other hand, for cucumber, Chinese flowering cabbage, and cabbage, a good number of pesticides (19, 18, and 15, respectively) showed negligible matrix effects. Furthermore, for carrot matrices, 21 pesticides showed a matrix enhancement effect. Excellent linearity was achieved at pesticide concentrations of 0.01-1.0 mg/L, and the limits of quantification (LOQ) for the developed method reached 0.01 mg/kg (except that for dinotefuran, which was 0.1 mg/kg), based on the spiked test. The developed method was successfully employed in the analysis of real samples in Nanning, China, and three pesticide residues (halosulfuron methyl, tebuconazole, and azoxystrobin) were commonly detected in vegetable samples. In the present study, a reliable method-validation performance and excellent cleanup effects were observed by using the modified MSPD method consisting of the FNPs in the cleanup step.

Metal-organic framework assisted matrix solid-phase dispersion microextraction of saponins using response surface methodology

An efficient and simple metal-organic framework (MOF) assisted matrix solid-phase dispersion (MSPD) microextraction was developed for the extraction of the five saponins in P. ginseng leaves. The target analyses were detected by ultra high performance chromatography coupled with time-of-flight MS. Experimental conditions for MSPD microextraction were optimized by the Box-Behnken design of the response surface methodology. The optimal conditions were as follows: 20 mg adsorbent, 80% methanol-water solution for elution, 60 s grinding time, and the MOF-808 as the adsorbent. With the final optimized method, the calibration curves for five saponins showed good linearity (R² > 0.998) within range of 0.01-100 μg/mL. In addition, analytical recoveries ranged from 87.04 to 103.78%, with the RSD below 5%. The limit of detection and LOQ range from 0.087 to 0.114 μg/mL and 0.292 to 0.379 μg/mL, respectively. Compared with the traditional extraction method and published methods, the newly MOF-assisted MSPD extract exhibited higher extraction efficiency, simpler operation, and provided a cleaner extract with low consumption of organic reagents that was applied for rapid evaluation and quality control of active compounds from plants.

Strategies for recycling and valorization of grape marc

Grapes are one of the most cultivated fruit crops worldwide. Either for wine or juice production, grape processing generates a large amount of residues that must be treated, disposed of or reused properly to reduce their pollution load before being applied to the soil. In this review, a special focus is given to the treatment and valorization of the winemaking by-product like grape marc via anaerobic digestion, composting and vermicomposting at laboratory, pilot, and industrial scales. The impact of the final products (digestates, composts, and vermicomposts) on soil properties is briefly addressed. Moreover, the role of grape marc and seeds as a valuable source of natural phytochemicals that include polyphenols and other bioactive compounds of interest for pharmaceutical, cosmetic, and food industries is also discussed. This is of paramount importance given the fact that sustainability requires the use of management and valorization strategies that allow the recovery of valuable compounds (e.g. antioxidants) with minimum disposal of waste streams.

A Review on the Recent Progress in Matrix Solid Phase Dispersion

Matrix solid phase dispersion (MSPD) has proven to be an efficient sample preparation method for solid, semi-solid, and viscous samples. Applications of MSPD have covered biological, food, and environmental samples, including both organic and inorganic analytes. This review presents an update on the development of MSPD in the period 2015~June 2018. In the first part of this review, we focus on the latest development in MSPD sorbent, including molecularly imprinted polymers, and carbon-based nanomaterials etc. The second part presents the miniaturization of MSPD, discussing the progress in both micro-MSPD and mini-MSPD. The on-line/in-line techniques for improving the automation and sample throughput are also discussed. The final part summarizes the success in the modification of original MSPD procedures.

Simultaneous determination and qualitative analysis of six types of components in Naoxintong capsule by miniaturized matrix solid-phase dispersion extraction coupled with ultra high-performance liquid chromatography with photodiode array detection and quadrupole time-of-flight mass spectrometry

A simple and effective sample preparation process based on miniaturized matrix solid-phase dispersion was developed for simultaneous determination of phenolic acids (gallic acid, chlorogenic acid, ferulic acid, 3,5-dicaffeoylqunic acid, 1,5-dicaffeoylqunic acid, rosmarinic acid, lithospermic acid, and salvianolic acid B), flavonoids (kaempferol-3-O-rutinoside, calycosin, and formononetin), lactones (ligustilide and butyllidephthalide), monoterpenoids (paeoniflorin), phenanthraquinones (cryptotanshinone), and furans (5-hydroxymethylfurfural) in Naoxintong capsule by ultra high-performance liquid chromatography. The optimized condition was that 25 mg Naoxintong powder was blended homogeneously with 100 mg Florisil PR for 4 min. One milliliter of methanol/water (75:25, v/v) acidified by 0.05% formic acid was selected to elute all components. It was found that the recoveries of the six types of components ranged from 61.36 to 96.94%. The proposed miniaturized matrix solid-phase dispersion coupled with ultra high-performance liquid chromatography was successfully applied to simultaneous determination of the six types of components in Naoxintong capsules. The results demonstrated that the proposed miniaturized matrix solid-phase dispersion coupled with ultra high-performance liquid chromatography could be used as an environmentally friendly tool for the extraction and determination of multiple bioactive components in natural products.

Kinetic modelling of mancozeb hydrolysis and photolysis to ethylenethiourea and other by-products in water

The aim of this study was to propose kinetic models suitable for reproducing and predicting mancozeb (Mz) conversion to by-products as a function of the operational conditions. The main factors (pH, temperature and light) potentially affecting the mancozeb degradation in aqueous models were studied by a multifactorial screening design. In addition, the response surface methodology (RSM) was applied to evaluate the interactive effects of these factors on ethylenethiourea (ETU) formation. The response surface revealed that the best degradation conditions to minimize mancozeb conversion to ETU were low pH (2), low temperature (25 °C) and darkness. Under these conditions, the percentage of mancozeb remained in the solution at 72 h was approximately 10% of the initial concentration and the percentage of ETU conversion was 5.4%. However, according to the model, in surface waters under typical environmental conditions (pH 8, 25 °C and light) the percentage of mancozeb conversion to ETU would be about 17.5%. The proposed model provides a satisfactory interpretation of the experimental data obtained during the hydrolysis of mancozeb.

Quantification of penoxsulam in soil and rice samples by matrix solid phase extraction and liquid-liquid extraction followed by HPLC-UV method

The paper exploits the development of novel, simple and sensitive methodology involving matrix solid phase dispersion (MSPD) and the comparison of MSPD with liquid-liquid extraction (LLE) for the evaluation of residual penoxsulam in soil and rice samples. Extracted samples were analyzed by high-performance liquid chromatography (HPLC) with ultraviolet detector at 230 nm. Both methods were optimized, considering different parameters, and under optimum conditions, the mean recoveries obtained were in the range of 85-104 % for MSPD and 78.8-90.7 % for LLE. Precision values expressed as relative standard deviation (RSD) were ≤10 for MSPD and ≤15 for LLE. Linearity for penoxsulam was in the range of 0.01-20 μg mL(-1) with limits of detection and limits of quantification of 0.01 and 0.03 mg kg(-1), respectively.

A mussel (Mytilus edulis) tissue certified reference material for the marine biotoxins azaspiracids

Azaspiracids (AZAs) are lipophilic biotoxins produced by marine algae that can contaminate shellfish and cause human illness. The European Union (EU) regulates the level of AZAs in shellfish destined for the commercial market, with liquid chromatography-mass spectrometry (LC-MS) being used as the official reference method for regulatory analysis. Certified reference materials (CRMs) are essential tools for the development, validation, and quality control of LC-MS methods. This paper describes the work that went into the planning, preparation, characterization, and certification of CRM-AZA-Mus, a tissue matrix CRM, which was prepared as a wet homogenate from mussels (Mytilus edulis) naturally contaminated with AZAs. The homogeneity and stability of CRM-AZA-Mus were evaluated, and the CRM was found to be fit for purpose. Extraction and LC-MS/MS methods were developed to accurately certify the concentrations of AZA1 (1.16 mg/kg), AZA2 (0.27 mg/kg), and AZA3 (0.21 mg/kg) in the CRM. Quantitation methods based on standard addition and matrix-matched calibration were used to compensate for the matrix effects in LC-MS/MS. Other toxins present in this CRM at lower levels were also measured with information values reported for okadaic acid, dinophysistoxin-2, yessotoxin, and several spirolides.

Evaluation of Antibacterial Enrofloxacin in Eggs by Matrix Solid Phase Dispersion-Flow Injection Chemiluminescence

The study based on the chemiluminescence (CL) reaction of potassium ferricyanide and luminol in sodium hydroxide medium, enrofloxacin (ENRO) could dramatically enhance CL intensities and incorporated with matrix solid-phase dispersion (MSPD) technique (Florisil used as dispersant, dichloromethane eluted the target compounds). A simple flow injection chemiluminescence (FL-CL) method with MSPD technique for determination of ENRO in eggs was described. Under optimal conditions, the CL intensities were linearly related to ENRO concentration ranging from4.0×10-8 g.L−1to5.0×10-5 g.L−1, with a correlation coefficient of 0.9989 and detection limit of5.0×10-9 g.L−1. The relative standard deviation was 3.6% at an ENRO concentration of2.0×10-6 g.L−1. Our testing technique can help ensure food safety, and thus, protect public health.

Optimization of matrix solid-phase dispersion for liquid chromatography tandem mass spectrometry analysis of 12 pharmaceuticals in sediments

The matrix solid-phase dispersion (MSPD) technique accompanied with LC-MS/MS detection for the purpose of determination of 12 pharmaceuticals (sulfaguanidine, sulfadiazine, sulfamethazine, sulfamethoxazole, trimethoprim, roxithromycin, praziquantel, febantel, enrofloxacin, ciprofloxacin, norfloxacin and procaine) applied to sediment samples has been described in this paper. Different parameters, such as the type of solid phase, the elution solvent and its volume have been investigated. The analytes were successfully extracted by C18 as an MSPD sorbent with 5 mL of acetonitrile:5% of oxalic acid=6:4 (v/v) as an elution solvent. The proposed method provides a linear response over the concentration range of 0.0005-100 μg/g, depending on pharmaceuticals with correlation coefficients above 0.9928 in all cases except for trimethoprim (0.9889). Also, the method has revealed low limits of detection (0.125-500 ng/g), good precision (intra and inter-day), a relative standard deviation below 15% and recoveries above 80%, except for roxithromycin, febantel and enrofloxacin. The method has been successfully applied to analysis of different sediment samples.

Multiresidue determination of veterinary drugs in aquaculture fish samples by ultra high performance liquid chromatography coupled to tandem mass spectrometry

A simple, selective and fast multiresidue method was developed for the determination of 32 veterinary drug residues belonging to several families, in gilthead sea bream (Sparus aurata) by ultra high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS). The extraction was based on modified QuEChERS (quick, easy, cheap, effective, rugged and safe) procedure, using as extraction solution a mixture of acetonitrile and methanol (75:25, v/v), and it reduces sample handling, increasing sample throughput in relation to current methodologies. The developed method was validated and mean recovery ranged from 69% to 125% (at 10, 25, 50 and 100 μg/kg). Intra and interday precision, estimated as the same levels and expressed as relative standard deviation, RSD, were lower than 20% and 30%, respectively. Limits of detection (LODs) and quantification (LOQs) were lower than 7.5 and 25 μg/kg, respectively, except for danofloxacin, oxytetracycline and tetracycline (LOD and LOQ of 15.0 and 50 μg/kg, respectively). Decision limit (CC(α)) and detection capability (CC(β)) were also calculated and ranged from 16.7 μg/kg (levamisole) to 605.0 (flumequine) μg/kg and from 23.5 μg/kg (levamisole) to 611.5 μg/kg (flumequine), respectively. The expanded uncertainty, U, was also evaluated ant it was below 25% at 100 μg/kg level, except for tetracycline (28%). Finally, the method was applied to ten samples obtained from local supermarkets in Almería (Spain) and traces of some compounds were detected.

Application of ultrasound-assisted matrix solid-phase dispersion extraction to the HPLC confirmatory determination of cephalosporin residues in milk

Ultrasound-assisted matrix solid-phase dispersion (MSPD) was applied to isolate eight cephalosporins (cefadroxil, cefaclor, cephalexin, cefotaxime, cefazolin, cefuroxime, cefoperazone and ceftiofur) from milk. Multi-residue analysis was subsequently performed by HPLC-diode array detection. Extraction yield by matrix solid-phase dispersion using Nexus sorbent was higher than various investigated SPE protocols. Three analytical columns, two conventional silica based and one monolithic, were compared based on resolution, peak shape and retention time. The optimum method using Chromolith RP-18e (100×4.6 mm) achieved separation in less than 16 min. Method validation was performed according to the European Union Decision 2002/657/EC, determining linearity, selectivity, stability, decision limit, detection capability, accuracy and precision. RSD values observed were lower than 15.3%. Recovery rates of examined antimicrobials from milk ranged from 93.8 to 101.9% for cefadroxil, from 94.7 to 103.6% for cefaclor, from 93.4 to 106.6% for cephalexine, from 104.1 to 115.3% for cefotaxime, from 97.1 to 105.6% for cefazolin, from 97.4 to 108.6% for cefuroxime, from 98.8 to 103.4% for cefoperazone and from 95.5 to 103.6% for ceftiofur. Correlation coefficients ranged from 0.9926 to 0.9999. CC(b) values were in the range from 103.5 to 112.3 μg/kg for analytes with a maximum residue limit of 100 μg/kg and from 54.4 to 56.3 μg/kg for those with a maximum residue limit of 50 μg/kg.

Pressurized hot water extraction (PHWE)

Pressurized hot water extraction (PHWE) has become a popular green extraction method for different classes of compounds present in numerous kinds of matrices such as environmental, food and botanical samples. PHWE is also used in sample preparation to extract organic contaminants from foodstuff for food safety analysis and soils/sediments for environmental monitoring purposes. The main parameters which influence its extraction efficiency are namely the temperature, extraction time, flow rates and addition of modifiers/additives. Among these different parameters studied, temperature is described as the most important one. It is reported that the extraction of certain compounds is rather dependent on pressurized water with different applied temperature. Thus, the stability and reduced solubilities of certain compounds at elevated temperatures are highlighted in this review. With some modifications, a scaled-up PHWE could extract a higher amount of desirable compounds from solid and powdered samples such as plant and food materials. The PHWE extracts from plants are rich in chemical compounds or metabolites which can be a potential lead for drug discovery or development of disease-resistant food crops.