Determination of fungicide residues in baby food by liquid chromatography–ion trap tandem mass spectrometry

Immunochromatographic visualization detection platform for bitertanol in foods

As a widely used fungicide in agriculture, bitertanol (BIT) significantly affects hormone regulation leading to imbalance of homeostasis in vivo, which makes it necessary to monitor BIT residues in foods. In this research, a novel hapten derivation scheme was designed by analyzing the chemical structure of BIT to prepare an anti-BIT monoclonal antibody with high affinity, specificity and sensitivity (half inhibitory concentration of 4.78 ng/mL). Subsequently, a visualized gold immunochromatographic assay (GICA) platform was established based on antigen-antibody specific recognition, with a limit of detection of 0.06 mg/kg and 0.18 mg/kg in cucumber and tomato, respectively. GICA has spiked recoveries of 84.3 %-114.1 %, determines results are not significantly different from those of LC-MS/MS, and the complex purification treatments can be reduced during the detection process. Therefore, the developed GICA is a reliable, rapid, and sensitive method for on-site rapid monitoring of BIT in foods.

Review of Characteristics and Analytical Methods for Determination of Thiabendazole

Thiabendazole (TBZ) is a fungicide and anthelmintic drug commonly found in food products. Due to its toxicity and potential carcinogenicity, its determination in various samples is important for public health. Different analytical methods can be used to determine the presence and concentration of TBZ in samples. Liquid chromatography (LC) and its subtypes, high-performance liquid chromatography (HPLC) and ultra-high-performance liquid chromatography (UHPLC), are the most commonly used methods for TBZ determination representing 19%, 18%, and 18% of the described methods, respectively. Surface-enhanced Raman spectroscopy (SERS) and fluorimetry are two more methods widely used for TBZ determination, representing 13% and 12% of the described methods, respectively. In this review, a number of methods for TBZ determination are described, but due to their limitations, there is a high potential for the further improvement and development of each method in order to obtain a simple, precise, and accurate method that can be used for routine analysis.

Carbendazim imprinted electrochemical sensor based on CdMoO4/g-C3N4 nanocomposite: Application to fruit juice samples

Carbendazim (CAR) as a fungicide is utilized for fruits and vegetables to provide diseases' control and the degradation of carbendazim having benzimidazole ring is slow. Herein, a molecularly imprinted electrochemical sensor based on CdMoO₄/g-C₃N₄ nanocomposite was prepared for CAR determination in fruit juice samples. Firstly, CdMoO₄/g-C₃N₄ nanocomposite with high yield was fabricated via one-pot in-situ hydrothermal approach including environmentally friendly method. Formation of CAR imprinted polymers was performed on CdMoO₄/g-C₃N₄ nanocomposite modified glassy carbon electrode (GCE) in presence of CAR as template and pyrrole (Py) as a monomer by cyclic voltammetry (CV) technique. Following the morphological, structural, and optical characterization of as-synthesized nanocomposite, the electrochemical techniques were also implemented to evaluate the electrochemical features of fabricated electrodes. The limit of quantification (LOQ) and limit of detection (LOD) values were calculated as 0.1 × 10^-10 M, and 2.5 × 10^-12 M, respectively in addition to satisfactory selectivity, stability, reproducibility and reusability. The findings revealed that the proposed CAR imprinted electrochemical sensor can be successfully employed in food safety.

Onsite/on-field analysis of pesticide and veterinary drug residues by a state-of-art technology: A review

Pesticides and veterinary drugs are generally employed to control pests and insects in crop and livestock farming. However, remaining residues are considered potentially hazardous to human health and the environment. Therefore, regular monitoring is required for assessing and legislation of pesticides and veterinary drugs. Various approaches to determining residues in various agricultural and animal food products have been reported. Most analytical methods involve sample extraction, purification (cleanup), and detection. Traditional sample preparation is time-consuming labor-intensive, expensive, and requires a large amount of toxic organic solvent, along with high probability for the decomposition of a compound before the analysis. Thus, modern sample preparation techniques, such as the quick, easy, cheap, effective, rugged, and safe method, have been widely accepted in the scientific community for its versatile application; however, it still requires a laboratory setup for the extraction and purification processes, which also involves the utilization of a toxic solvent. Therefore, it is crucial to elucidate recent technologies that are simple, portable, green, quick, and cost-effective for onsite and infield residue detections. Several technologies, such as surface-enhanced Raman spectroscopy, quantum dots, biosensing, and miniaturized gas chromatography, are now available. Further, several onsite techniques, such as ion mobility-mass spectrometry, are now being upgraded; some of them, although unable to analyze field sample directly, can analyze a large number of compounds within very short time (such as time-of-flight and Orbitrap mass spectrometry). Thus, to stay updated with scientific advances and analyze organic contaminants effectively and safely, it is necessary to study all of the state-of-art technology.

Chromatographic Methods for Detection and Quantification of Carbendazim in Food

Carbendazim (CBZ), which is a fungicide widely used for the management of plant diseases, has been detected in a number of food products. The negative effects of CBZ to human health have stimulated the reduction of the maximum residue limits (MRLs), and subsequently the development of reliable and sensitive detection methods. Here, we are reviewing for the first time all reported chromatographic methods for the detection and quantification of CBZ in food. Several techniques, including liquid chromatography (LC), thin layer chromatography (TLC), micellar electrokinetic chromatography (MEKC), and supercritical fluid chromatography (SFC), were used for the separation and detection of CBZ, showing diverse characteristics and sensitivity. Some methods allowed the specific determination of CBZ, whereas other methods were successfully applied for the simultaneous quantification of a huge number of pesticides. Most reported methods showed limits of detection (LOD) and quantification (LOQ) lower than the MRLs. Relevant efforts in the field have been directed toward the simplification and optimization of the extraction steps prior to the chromatographic separation to increase the recovery and reduce the matrix effects. In this Review, the matrices, extraction procedures, and separation and detection parameters are detailed and compared in order to provide new insights on the development of new reliable methods for the detection of CBZ in food.

In situ analysis of pesticide residues on the surface of agricultural products via surface-enhanced Raman spectroscopy using a flexible Au@Ag–PDMS substrate

In situ analysis of pesticide residues on the surface of agricultural products via surface-enhanced Raman spectroscopy using a flexible Au@Ag–PDMS substrate.

Stereoselective Separation of the Fungicide Bitertanol Stereoisomers by High-Performance Liquid Chromatography and Their Degradation in Cucumber

Bitertanol is a widely used triazole fungicide and consists of four stereoisomers. A new high-performance liquid chromatography (HPLC) method was developed for simultaneous analysis of the four stereoisomers in apple, pear, tomato, cucumber, and soil. The mechanism of separation was explained with molecular docking and effects of thermodynamic parameters on the resolution. The absolute configuration and optical rotation of four stereoisomers were confirmed by X-ray diffraction and HPLC tandem circular dichroism, respectively. A good linearity ( R² ≥ 0.999) was obtained for four stereoisomers in all matrix-matched calibration curves in the range of 0.02-10 mg/L. The mean recoveries of four stereoisomers in five matrices ranged from 74.6% to 101.0% with an intraday and interday relative standard deviation from 0.6% to 9.9%. Stereoselective degradation of bitertanol in cucumber was observed: (1 R,2 S)-bitertanol and (1 R,2 R)-bitertanol were preferentially degraded with enantiomeric fraction values from 0.5 to 0.43 at 7 d and 0.42 at 5 d, respectively. This research provides a useful tool for the analysis of bitertanol stereoisomers.

Simultaneous determination of residues of metalaxyl, cyazofamid and a cyazofamid metabolite in tobacco leaves and soil by liquid chromatography with tandem mass spectrometry

A simple method was developed and validated for the simultaneous determination of metalaxyl, cyazofamid and the cyazofamid metabolite 4-chloro-5-p-tolylimidazole-2-carbonitrile (CCIM) by liquid chromatography with tandem mass spectrometry. The three target compounds were extracted from tobacco and soil with acetonitrile containing 0.1% acetic acid, and the extracts were purified using octadecylsilane. The proposed method showed satisfactory linearity (R2 ≥ 0.9985) for the target compounds. The limits of detection for metalaxyl, cyazofamid and CCIM were 0.006, 0.06 and 0.06 mg/kg in soil and green tobacco leaves and 0.03, 0.3 and 0.3 mg/kg in cured tobacco leaves, respectively. The limits of quantification for metalaxyl, cyazofamid and CCIM were 0.02, 0.2 and 0.2 mg/kg in soil and green tobacco leaves and 0.1, 1 and 1 mg/kg in cured tobacco leaves, respectively. The average recoveries from soil and tobacco were 72.91-98.40% for metalaxyl, 76.73-105.80% for cyazofamid and 74.48-106.45% for CCIM. The relative standard deviation range was 1.23-6.99%. The developed method was successfully applied to analysis of residues of metalaxyl, cyazofamid and CCIM in real soil and tobacco samples. The results indicated that the established method could meet the requirement for the analysis of trace amounts of all three analytes in soil and tobacco.

Investigation of targeted pyrrolizidine alkaloids in traditional Chinese medicines and selected herbal teas sourced in Ireland using LC-ESI-MS/MS

Publications linking hepatotoxicity to the use of herbal preparations are escalating. Herbal teas, traditional Chinese medicines (TCMs) and dietary supplements have been shown to contain pyrrolizidine alkaloids (PAs). Acute PA toxicosis of the liver can result in sinusoidal-obstruction syndrome, also known as veno-occlusive disease (VOD). This paper describes a sensitive and robust method for the detection of targeted PAs and their N-oxides (PANOs) in herbal products (selected herbal teas and TCMs) sourced within Ireland. The sample preparation includes a simple acidic extraction with clean-up via solid-phase extraction (SPE). Sample extracts were accurately analysed by using LC-ESI-MS/MS applying for the first time a pentafluorophenyl (PFP) core-shell column to the chromatographic separation of PAs and PANOs. The method was validated for selectivity, taking into consideration matrix effects, specificity, linearity, precision and trueness. Limits of detection (LOD) and limits of quantitation (LOQ) were quantified for all PAs and PANOs ranging from 0.4 to 1.9 µg kg⁻¹ and from 1.3 to 6.3 µg kg⁻¹, respectively. In this study 10 PAs and four PANOs were targeted because they are commercially available as reference standards. Therefore, this study can only report the levels of these PAs and PANOs analysed in the herbal teas and TCMs. The results reported represent the minimum levels of PAs and PANOs present in the samples analysed; commercially available herbal teas (n = 18) and TCMs (n = 54). A total of 50% herbal teas and 78% Chinese medicines tested positive for one or more PAs and/or PANOs included within this study, ranging from 10 to 1733 and from 13 to 3668 µg kg⁻¹, respectively.

Simultaneous enantioselective determination of triazole fungicide flutriafol in vegetables, fruits, wheat, soil, and water by reversed-phase high-performance liquid chromatography

A novel and effective method for enantioselective determination of flutriafol enantiomers in food and environmental matrices (cucumber, tomato, grape, pear, wheat, soil, and water) has been developed. The (R)-(-)-flutriafol was first eluted and measured from electronic circular dichroism spectra using a cellulose tris(3-chloro-4-methyl phenyl carbamate) chiral column. The mean recoveries from the samples ranged from 82.9% to 103.4%, with intraday relative standard deviations (RSD) of 2.2-8.3% and interday RSD of 3.4-7.9%. Good linearity (R(2) ≥ 0.9989) was obtained for all analytes matrix calibration curves within the range of 0.1-10 mg/kg. The limits of detection for two enantiomers in the seven matrices were all below 0.015 mg/kg. The results show that the proposed method is convenient and reliable for the enantioselective detection of the flutriafol in the real samples and is applicable to the environmental stereochemistry of flutriafol in food and environmental matrices.

Micellar electrokinetic chromatography method development for simultaneous determination of thiabendazole, carbendazim, and fuberidazole

Thiabendazole (TBz), carbendazim (CBz), and fuberidazole (FBz) are systemic benzimidazole-type fungicides used for pre- and post-harvest treatment to control various types of fungal diseases on a variety of crops. Significant levels of these fungicides could alter the composition or flavour of crops, and being possible carcinogens, they could also pose risks for humans and the environment. A mode of capillary electrophoresis called micellar electrokinetic chromatography (MEKC) was investigated for the determination of these three benzimidazole fungicides. The study involved two kinds of surfactants in which several experimental conditions were optimized, i.e., buffer concentration, pH, micelle concentration, and percent organic modifier (methanol). Using the optimum experimental conditions, the fungicides were successfully separated by MEKC. The limits of detection and quantification were in the range of 0.6-0.7 and 2.1-2.5 mg L(-1), respectively, and the calibration curves were linear over the range of 5-60 mg L(-1) for the three fungicides. The potential of the proposed MEKC method was demonstrated by analyzing water samples which were fortified with the fungicides. The proposed method enabled simultaneous determination of the three benzimidazole fungicides and method validation with spiked water samples yielded satisfactory quantitative recoveries for all the three fungicides.