Multiclass pesticide analysis in fruit-based baby food: A comparative study of sample preparation techniques previous to gas chromatography–mass spectrometry

Improved efficiency of ion trapping time-of-flight mass spectrometry for the analysis of pesticide residues and mycotoxins at trace levels in baby food

The analysis of pesticide residues and mycotoxins in baby food demands exceptionally low limits of quantitation, necessitating the use of highly sensitive instruments capable of conducting trace analyses. High-resolution instruments typically fail to detect such low levels. However, the latest advancements in liquid time-of-flight technology, when coupled with ion trapping, enable ion enrichment, thereby improving detection levels. This allows for the analysis of these substances at low concentration levels, benefiting from enhanced mass accuracy. Additionally, the use of mass accuracy data helped eliminate matrix interferences, thereby enabling high-confidence identification. We developed a multi-residue method to analyse 219 pesticide residues and 9 mycotoxin residues in baby food matrices. Utilizing a QuEChERS-based extraction method, the samples were then analysed using an LC-ZenoTOF 7600 system with mass window screening acquisition. For pesticides, the limit of quantitation was 0.001-0.003 mg/kg for 81 % of the evaluated compounds, 0.005 mg/kg for 13 %, 0.010 mg/kg for 4 % and 0.020-0.030 for 2 %; good linearities were obtained at these levels. Apparent recoveries were evaluated at 0.003, 0.005, and 0.010 mg/kg. At the lowest recovery level, 93 % of compounds showed recoveries between 70 and 120 %. The rest of the compounds were in the range of 63-129 %, with relative standard deviation values below 20 %. For mycotoxins, the limits of quantitation ranged from 0.0001 to 0.100 mg/kg, with matrix-matched concentrations assessed within this range. Recoveries were evaluated at low concentration range (0.001-0.003 mg/kg) and high range (0.020-0.050) with apparent recoveries values between 92 and 140 %. Finally, a total of 31 commercial baby food samples were analysed using this method. The results indicated that 16 samples contained pesticide residues, while two samples were found to have mycotoxins.

Determination of pesticide residues in soybeans using QuEChERS followed by deep eutectic solvent-based DLLME preconcentration prior to gas chromatography-mass spectrometry analysis

A reliable and greener alternative to the usual extraction methods is reported for the determination of pesticide residues in soybeans. This novel approach combines the classical QuEChERS extraction method with a DLLME (dispersive liquid-liquid microextraction) step, utilizing a deep eutectic solvent (DES) - camphor: hexanoic acid (1:1 molar ratio) - as the microextraction solvent. This DES has never been employed in pesticide analysis by gas chromatography-mass spectrometry of complex matrices like soybeans. A Plackett-Burman screening design was employed to optimize sample preparation variables of QuEChERS (amount of sodium chloride and magnesium sulfate, and amount of PSA and C18 sorbents) and DLLME (pH of medium, amount of sodium chloride, and volume of microextraction solvent). This design allowed for a systematic evaluation of the impact of each parameter on the method's performance. The optimized method was evaluated using a certified reference material and commercial samples of soybeans. The method exhibited high accuracy and precision for most of the analytes under study, demonstrating its applicability for pesticide residue analysis in soybeans. To assess the greenness and practicality of the developed method, the Analytical Greenness (AGREE) and Blue Applicability Grade Index (BAGI) metric systems were employed, respectively. Overall, the proposed QuEChERS-DLLME method using a DES solvent is a reliable and greener alternative to conventional extraction methods for the determination of pesticide residues in soybeans. Its high performance, coupled with its environmental friendliness, makes it a promising tool for food safety analysis.

Development of Fluorescent Co (II)-Integrated Carbon Dots and Their Application as a Off-On Mesotrione Detection Sensor

A very simple mesotrione-sensing medium with enhanced sensitivity detection limits has been proposed. A renovated hydrothermal method was adopted for synthesizing fluorescent carbon dots from ethylenediamine and glucose using a Teflon-lined simple autoclave in a GC oven. The resultant carbon dots were characterized via TEM, FTIR, UV-vis, particle size distribution, and EDX and evaluated in a fluorimeter as the sensing medium for mesotrione detection. The binding approach of the Co (II)-integrated glucose-bound carbon dots toward mesotrione is selective, making them an effective sensor for the real sample applications, where majority of the coexisting substances showed insignificant interference effect. Formation of the metastable state due to the molecular interaction between carbon dots and Co (II) resulted in fluorescence quenching at 456 nm. Enhancement in the fluorescence intensity occurred when mesotrione was added in the concentration range of 0.2-5.0 μg mL-1, with a limit of detection, limit of quantification, standard deviation, and relative standard deviation of 0.054, 0.164, 0.00082 μg mL-1, and 0.682%, respectively. Mesotrione determination was demonstrated in soil, water, and tomato samples with recoveries in the range of 95.38-104.7%. The selectivity of the sensor was found to be good enough when checked for the complex tomato sample spiked with different pesticides of the triketone family having structural similarities to mesotrione.

Assessment of quality and safety aspects of homemade and commercial baby foods

Dietary Guidelines in some countries recommend avoiding commercially processed baby food, while others encourage the consultation of ingredients and nutritional information. Therefore, the objective of this study was to systematically analyze different baby foods obtained from commercial market and "homemade" produced, in order to verify whether comercial products have low nutritional and unsafety attributes. The samples were analyzed for chemical composition, physicochemical aspects, texture, microbiological and mycotoxin contamination, and pesticide residues. Results showed that, in general, commercial samples have a higher energy density and better ratio of macronutrients. The sodium, pH, and texture of both products were in accordance with the recommendations. None of the baby foods evaluated were contaminated with yeast and molds, total coliforms, or Escherichia coli; however, Salmonella sp. was confirmed in one homemade sample. Pesticide residues were detected in all analyzed baby food samples; however, at lower levels than the limit of quantification. Ochratoxin A was detected in one homemade baby food sample (5.76 µg /kg). Considering the samples evaluated, commercial baby food samples appeared to be safer in relation to microbiological, pesticide residue standards, and mycotoxin contamination. Therefore, it could be concluded that the quality of commercial and homemade baby foods still needs to be improved, as well as more studies related to a critical analyses of both types of processes used.

Synthesis of fructose bound Fe(iii) integrated carbon dots as a robust turn-off detection sensor for chlortoluron

A simple, sensitive, and robust fluorescent sensor for chlortoluron detection has been developed. Fluorescent carbon dots were synthesized using ethylene diamine and fructose via a hydrothermal protocol. The molecular interaction between fructose carbon dots and Fe(iii) resulted in a fluorescent metastable state exhibiting remarkable fluorescence quenching at λ_em of 454 nm and interestingly, further quenching occurred upon the addition of chlortoluron. The quenching in the fluorescence intensity of CDF-Fe(iii) towards chlortoluron occurred in the concentration range of 0.2-5.0 μg mL^-1 where the limit of detection was found to be 0.0467 μg mL^-1, the limit of quantification was 0.14 μg mL^-1, and the relative standard deviation was 0.568%. The selective and specific recognitive nature of the Fe(iii) integrated fructose bound carbon dots towards the chlortoluron make it a suitable sensor for real sample applications. The proposed strategy was applied for the determination of chlortoluron in soil, water, and wheat samples with recoveries in the range of 95% to 104.3%.

Multi-analyte gas chromatography-mass spectrometry method to monitor bisphenols, musk fragrances, ultraviolet filters, and pesticide residues in seafood

A gas chromatography-mass spectrometry method for the analysis of thirty-six anthropogenic contaminants in the edible portion of four distinct seafood items is reported. Considering the heterogeneous composition of algae, mussels, and lean/fatty fish muscles, a generic sample preparation based on the QuEChERS procedure combined with dispersive liquid-liquid microextraction (DLLME) with in situ acetylation was successfully applied for quantification of pesticide residues, bisphenols, musk fragrances and UV-filters. Matrix effects were influenced by the type of seafood, with the lowest effects being observed with EMR-lipid and graphitized carbon black sorbents in dispersive solid-phase extraction cleanup step. Method performance features were successful evaluated in the different seafood samples - algae, mussel, lean and fatty fish muscles, following the criteria established by SANTE/12682/2019 for analytical methods for pesticide residues analysis. The detection and quantification of bisphenol F, musk fragrances (galaxolide and tonalide), UV-filters (2-ethylhexyl salicylate, 2-ethylhexyl 4-methoxycinnamate, and isoamyl 4-methoxycinnamate), and residues of permethrin in commercial samples of algae, mussel and fish collected in a Portuguese estuary support the suitability of the proposed method for future seafood monitoring by food safety authorities.

Recent progress in smartphone-based techniques for food safety and the detection of heavy metal ions in environmental water

Emerging smartphone-based point-of-care tests (POCTs) are cost-effective, precise, and easy to implement in resource-limited areas. Thus, they are considered a potential alternative to conventional diagnostic testing. This review explores food safety and the detection of metal ions in environmental water based on unprecedented smartphone technology. Specifically, we provide an overview of various methods used for target analyte detection (antibiotics, enzymes, mycotoxins, pathogens, pesticides, small molecules, and metal ions), such as colorimetric, fluorescence, microscopic imaging, and electrochemical methods. This paper performs a comprehensive review of smartphone-based POCTs developed in the last three years (2018-2020) and evaluates their relative advantages and limitations. Moreover, we discuss the imperative role of new technology in the progress of POCTs. Sensor materials (metal nanoparticles, carbon dots, quantum dots, organic substrates, etc.) and detection techniques (paper-based, later flow assay, microfluidic platform, etc.) involved in POCTs based on smartphones, and the challenges faced by these techniques, are addressed.

Hyphenated dispersive solid- and liquid-phase microextraction technique based on a hydrophobic deep eutectic solvent: application for trace analysis of pesticides in fruit juices

BACKGROUND

Pesticides are extensively used worldwide to control plant pathogens and prevent agricultural product damage. However, they can pollute the environment and endanger human health. So far, a variety of sample preparation methods have been developed for the analysis of pesticide residues.

RESULTS

A hyphenated solid-liquid microextraction method based on a new adsorbent of magnetic graphene oxide functionalized by (3-glycidyloxypropyl)trimethoxysilane and a deep eutectic solvent (choline chloride/4-chlorophenol (1:2)) was developed for extraction/preconcentration of trace levels of pesticides. The sorbent was characterized using scanning electron microscopy, Fourier transform infrared spectroscopy, and vibrating sample magnetometry. In-syringe magnetic dispersive solid-phase extraction in tandem with dispersive liquid-liquid microextraction followed by gas chromatography was applied for the analysis of the selected pesticides. The main parameters governing sample preparation efficiency, including adsorbent dosage, desorption conditions, pH, extraction time, deep eutectic solvent volume, and salt concentration, were investigated. The linear ranges were 0.024-500 μg L^-1 with 0.9971-0.9999 linearity factor (R² ). The limits of detection and quantification were 0.006-0.038 and 0.024-0.126 μg L^-1 , respectively. The relative standard deviations were 0.5-4.2% for intra-day analysis and 2.7-4.6% for inter-day analysis. Enrichment factors were in the range 210-540.

CONCLUSIONS

The method was successfully applied for the determination of malathion, heptachlor epoxide, endrin, dichlorodiphenyltrichloroethane, azinphos ethyl, cypermethrin, and deltamethrin in fruit juice samples (apple, pineapple, cherry, peach, and red and green grape juices) and the recoveries were within the range 71-115%. © 2020 Society of Chemical Industry.

Development and evaluation of an automated multi-channel multiplug filtration cleanup device for pesticide residue analysis on mulberry leaves and processed tea

An automated multi-channel multiplug filtration cleanup (m-PFC) device was designed and developed. m-PFC columns were suitably installed in the device. The cycle times, speed and nitrogen pressure parameters of the m-PFC column were optimized. The device was utilized to analyze the 82 pesticide residues in fresh mulberry leaves and processed tea with GC-MS/MS detection. Method validation was performed on 82 pesticide residues in fresh mulberry leaves and processed tea at spiked levels of 0.01, 0.05 and 0.5 mg kg⁻¹. The fortified recoveries of 82 pesticides were 72–115% and the relative standard deviations were 1–15%, except for diniconazole and clodinafop-propargyl in mulberry leaves. The automated multi-channel m-PFC device was successfully applied to detect the pesticide residues in fresh mulberry leaves and processed tea samples. With comparison to the conventional QuEChERS method, the current method using this device did not need additional vortex or centrifugation steps, and could process 48–64 samples in about one hour. The automated m-PFC method saved labor and improved the precision and was shown to be efficient and practical in pesticide residue analysis.

An automated device based on QuEChERS cleanup was developed, which is simple, fully automated, highly precise and highly efficient.

Sorbent-excluding sample preparation method for GC-MS pesticide analysis in apple peel

Apple peel is frequently exposed to pesticides, especially in the last stages of the pesticide treatment practice. For a certain period, peel retains most of the applied pesticides, which precisely indicates the presence of pesticide residues. This study was conducted to establish and evaluate the method for the residue analysis of pyrimethanil, cyprodinil, trifloxystrobin, bifenthrin and boscalid by GC-MS in peel of Granny Smith, Golden Delicious and Idared varieties. The method consisted of few steps, without the routine usage of sorbents, and resulted in efficient removal of waxes, targeted as main interferences in GC-MS analysis. The matrix effect, boscalid selectivity issue, trend of lower trueness for bifenthrin in all matrices and for all analytes in Granny Smith matrix were in some way associated with the waxes. Finally, the method was applied to the analysis of three varieties of apple orchard samples, after 9 and 5 months of treatment with commercial formulations that contain pyrimethanil, cyprodinil and boscalid as active ingredients. Since the developed method consisted of few steps and used nontoxic and economic reagents, it could be implemented as a fast, economic and reliable screening method.

Recent Modifications and Validation of QuEChERS-dSPE Coupled to LC-MS and GC-MS Instruments for Determination of Pesticide/Agrochemical Residues in Fruits and Vegetables: Review

Fruits and vegetables constitute a major type of food consumed daily apart from whole grains. Unfortunately, the residual deposits of pesticides in these products are becoming a major health concern for human consumption. Consequently, the outcome of the long-term accumulation of pesticide residues has posed many health issues to both humans and animals in the environment. However, the residues have previously been determined using conventionally known techniques, which include liquid-liquid extraction, solid-phase extraction (SPE) and the recently used liquid-phase microextraction techniques. Despite the positive technological effects of these methods, their limitations include; time-consuming, operational difficulty, use of toxic organic solvents, low selective property and expensive extraction setups, with shorter lifespan of instrumental performances. Thus, the potential and maximum use of these methods for pesticides residue determination has resulted in the urgent need for better techniques that will overcome the highlighted drawbacks. Alternatively, attention has been drawn recently towards the use of quick, easy, cheap, effective, rugged and safe technique (QuEChERS) coupled with dispersive solid-phase extraction (dSPE) to overcome the setback challenges experienced by the previous technologies. Conclusively, the reviewed QuEChERS-dSPE techniques and the recent cleanup modifications justifiably prove to be reliable for routine determination and monitoring the concentration levels of pesticide residues using advanced instruments such as high-performance liquid chromatography, liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry.

Simultaneous determination of organophosphorus pesticides and phthalates in baby food samples by ultrasound-vortex-assisted liquid-liquid microextraction and GC-IT/MS

Baby foods are either a soft, liquid paste or an easily chewed food since babies lack developed muscles and teeth to chew effectively. Babies typically move to consuming baby food once nursing or formula is not sufficient for the child's appetite. Some commercial baby foods have been criticized for their contents. This article focuses on the simultaneous determination of organophosphorus pesticides and phthalates by means of a method based on ultrasound-vortex-assisted liquid-liquid microextraction coupled with gas chromatography-ion trap mass spectrometry (GC-IT/MS). The protocol developed allowed the determination of six phthalates [dimethyl phthalate, diethyl phthalate, dibutyl phthalate, isobutyl cyclohexyl phthalate, benzyl butyl phthalate, bis(2-ethylhexyl) phthalate] and 19 organophosphorus pesticides. Freeze-dried product samples (0.1-0.2 g) were dissolved in 10 mL of warm distilled water along with 5 μL of an internal standard (anthracene at 10 mg mL^-1 in acetone): the choice of extraction solvent was studied, with the most suitable being n-heptane, which is used for phthalate determination in similar matrices. The solution, held for 5 min in a vortex mixer and for 6 min in a 100-W ultrasonic bath to favor solvent dispersion and consequently analyte extraction, was centrifuged at 4000 rpm for 30 min. Then 1 μL was injected into the GC-IT/MS system (SE-54 capillary column; length 30 m, inner diameter 250 μm, film thickness 0.25 μm). All analytical parameters investigated are discussed in depth. The method was applied to real commercial freeze-dried samples: significant contaminant concentrations were not found. Graphical abstract Simultaneous and sensitive determination of organophosphorus pesticides and phthalates in baby foods by the ultrasound-vortex-assisted liquid-liquid microextraction ֪gas chromatography-ion trap mass spectrometry procedure. 1 methacrifos, 2 pirofos, 3 phorate, 4 seraphos, 5 diazinon, 6 etrimphos, 7 dichlofenthion, 8 chlorpyrifos-methyl, 9 pirimiphos-methyl, 10 malathion, 11 chlorpyrifos, 12 parathion-ethyl, 13 pirimiphos-ethyl, 14 bromophos, 15 chlorfenvinphos, 16 bromophos-ethyl, 17 stirophos, 18 diethion, 19 coumaphos, A dimethyl phthalate, B diethyl phthalate, C dibutyl phthalate, D butyl cyclohexyl phthalate, E benzyl butyl phthalate, F bis(2-ethylhexyl) phthalate, IS internal standard.

Hollow-Fibre-Supported Dispersive Liquid-Liquid Microextraction for Determination of Atrazine and Triclosan in Aqueous Samples

We report the application of the dispersive liquid-liquid microextraction coupled to hollow-fibre membrane-assisted liquid-phase microextraction and its application for extraction of atrazine and triclosan. Under optimum conditions, namely, 25 μL of a 1 : 4 chlorobenzene : ethyl acetate mixture dispersed in 1 mL of aqueous sample, 10% (m/v) NaCl, a magnetic stirrer speed at 600 rpm, and 10 minutes' extraction time with toluene-filled fibre as the acceptor phase, the method demonstrates sufficient figures of merit. These include linearity (R² ≥ 0.9975), intravial precision (%RSD ≤ 7.6), enrichment factors (127 and 142), limits of detection (0.0081 and 0.0169 µg/mL), and recovery from river water and sewerage (96–101%). The relatively high detection limits are attributed to the flame ionization detector which is less preferred than a mass spectrometer in trace analyses. This is the first report of a homogenous mixture of the dispersed organic solvent in aqueous solutions and its employment in extraction of organic compounds from aqueous solutions. It therefore adds yet another candidate in the pool of miniaturised solvent microextraction techniques.