Multiresidue pesticide analysis of ginseng powders using acetonitrile- or acetone-based extraction, solid-phase extraction cleanup, and gas chromatography-mass spectrometry/selective ion monitoring (GC-MS/SIM) or -tandem mass spectrometry (GC-MS/MS)

Analytical challenges related to the measurement of chlorothalonil in serum in the perspective of human biomonitoring studies

Chlorothalonil (CTN) is a popular fungicide widely used in the world. However, its determination in serum samples is highly challenging, preventing a reliable investigation of human CTN internal exposure. We first investigated CTN's behaviour all along this analytical process on spiked serum samples. We used a radiolabelled 14C-CTN standard to monitor CTN in spiked serum samples and observed (1) a complete degradation of CTN in deproteinised serum samples after 4 h of contact; (2) a strong interaction between serum proteins and CTN by-products, with only 20 % of the radioactivity found to be extractable after 24 h of contact and (3) a slightly improved stability of CTN in serum following a first step of acidification or EDTA addition to samples. Using liquid chromatography coupled to high resolution mass spectrometry, 4-hydroxy-2,5,6-trichloroisophthalonitrile (HCTN) was identified as the major serum by-product of CTN. A protocol was developed to monitor both extractable CTN and HCTN from serum. This method was implemented on 36 human adult serum samples from the French "Esteban" Cohort. No free CTN was identified in these serum samples. Conversely, HCTN was detected in all samples at concentrations around 15 ± 2 ng mL-1, corresponding to the extractable fraction of CTN. Thus, HCTN may constitute a relevant biomarker of human internal exposure. Of note, the potential CTN contamination during blood collection could also be a source of HCTN detection in serum samples. Finally, blood sampling in EDTA tubes would seem more appropriate than in dry tubes for any future internal exposure studies on CTN.

Organophosphate Detection in Animal-Derived Foods Using a Modified Quick, Easy, Cheap, Effective, Rugged, and Safe Method with Liquid Chromatography-Mass Spectrometry

Organophosphates are widely used in the livestock industry. In this study, we developed a method for detecting 27 organophosphate insecticides in animal-derived foods, including beef, pork, chicken, milk, and eggs, using liquid chromatography-tandem mass spectrometry. A modified QuEChERS method was optimized for sample pretreatment. A mixture of acetonitrile and acetone was used as the extraction solvent, and MgSO4 and NaCl were used as salts. Among the five different dispersive solid-phase extraction systems, MgSO4, primary secondary amines, and C18 were selected for purification because they had the highest recovery rates and least matrix effects. The matrix-dependent limit of quantitation was 0.0005-0.005 mg/kg, and the correlation coefficient of the matrix-matched calibration curve was >0.99, which was acceptable for quantifying residues below 0.01 mg/kg-the default maximum residue limit in a positive list system. The recovery efficiencies ranged from 71.9 to 110.5%, with standard deviations ranging from 0.2% to 12.5%, satisfying the SANTE guidelines. The established analytical method was used to monitor organophosphates in animal-derived foods obtained from a local market, and no pesticides were detected. With respect to industry standards, our proposed method is recommended for practical organophosphate detection in animal-derived foods.

Isolation of the Endophytic Fungus Aspergillus terreus from a Halophyte (Tetraena qatarensis) and Assessment of Its Potential in Tomato Seedling Protection

Living in diverse environmentally harsh conditions, the plant exhibits a unique survival mechanism. As a result, the endophytes residing within the plant produce specific compounds that promote the plant's growth and defend it against pathogens. Plants and algae symbiotically harbor endophytes, i.e., microbes and microorganisms living within them. The objective of this study is to isolate endophytic fungi, specifically strains of Aspergillus terreus, from the leaves of the salt-tolerant plant Tetraena qatarensis and to explore the salt tolerance, antagonistic activity, and growth promotion properties. Strain C A. terreus (ON117337.1) was screened for salt tolerance and antagonistic effects. Regarding salt tolerance, the isolate demonstrated the ability to thrive in a concentration of up to 10% NaCl. A. terreus showed inhibitory activity against four fungal phytopathogens, namely Fusarium oxysporum, Alternaria alternata, Colletotrichum gloeosporioides, and Botrytis cinerea. The GC-MS investigation of the fungal (strain C Aspergillus terreus) extract showed the presence of about 66 compounds (secondary metabolites). Secondary metabolites (SMs) are produced, like Hexadecanoic acid, which aids in controlling phytopathogens. Also produced is lovastatin, which is used to treat hypercholesterolemia. Strain C, which showed salinity tolerance and the highest inhibitory activity, was further analyzed for its effect on tomato seed germination under pathogen stress from Fusarium oxysporum. The greenhouse experiment indicated that the fungi increased the length of tomato seedlings and the plant biomass. Therefore, the selected endophytes derived from Tetraena qatarensis were scrutinized for their potential as biocontrol agents, aiming to thwart fungal pathogens and stimulate plant growth. The in vitro and in vivo assessments of strain C (Aspergillus terreus) against Fusarium oxysporum in this investigation indicate the promising role of endophytes as effective biological control agents. Investigating novel bio-products offers a sustainable approach to agriculture, gradually reducing dependence on chemical fungicides.

Determination of Lincomycin in Milk Using Cu-Based Metal-Organic Framework Adsorbent and Liquid Chromatography-Tandem Mass Spectrometry

Antibiotic drug residues can adversely affect the human body. Lincomycin is a common veterinary drug that can form residues in foods of animal origin. However, the detection of trace residue levels of lincomycin residues in real samples is challenging. Here, a simple solid phase extraction (SPE) method was developed for the enrichment of lincomycin from cow milk samples before its detection by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The adsorbent used in the SPE was a Cu-based metal-organic framework (Cu-MOF) prepared by the solvothermal synthesis approach. The prepared MOFs were characterized using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), X-ray diffractometry (XRD), differential thermogravimetric analysis (TG-DTA), and N2 adsorption-desorption experiments. The adsorption capacity (adsorption equilibrium, extraction time, pH), and elution solvent parameters were investigated. Under the optimized conditions of the HPLC-MS/MS method, lincomycin was detected in the linear range of 10-200 g/L with a detection limit of 0.013 ng/mL. Commercial milk samples were spiked with lincomycin, and a recovery rate between 92.3% and 97.2% was achieved. Therefore, the current method can be successfully applied for the enrichment and determination of lincomycin from milk samples.

Medicinal herbs and multiple sclerosis: Overview on the hard balance between new therapeutic strategy and occupational health risk

Multiple sclerosis (MS) is an autoimmune disease characterized by demyelination and axonal loss of the central nervous system (CNS). Despite its spread throughout the world, the mechanisms that determine its onset are still to be defined. Immunological, genetic, viral, and environmental factors and exposure to chemicals may trigger MS. Many studies have highlighted the anti-inflammatory and anti-oxidant effects of medicinal herbs, which make them a natural and complementary treatment for neurodegenerative diseases. A severe reduction of several MS symptoms occurs with herbal therapy. Thus, the request for medicinal plants with potential beneficial effects, for MS patients, is constantly increasing. Consequently, a production increase needs. Unfortunately, many medicinal herbs were untested and their action mechanism, possible adverse effects, contraindications, or interactions with other drugs, are poorly or not investigated. Keeping in mind the pathological mechanisms of MS and the oxidative damages and mitochondrial dysfunctions induced by pesticides, it is important to understand if pesticides used to increase agricultural productivity and their residues in medicinal plants, may increase the risk of developing MS in both workers and consumers. Studies providing some indication about the relationship between environmental exposure to pesticides and MS disease incidence are few, fragmentary, and discordant. The aim of this article is to provide a glance at the therapeutic potential of medicinal plants and at the risk for MS onset of pesticides used by medicinal plant growers and present in medicinal herbs.

Improved chromatographic performance in red chilli powder pesticide residue quantitation by retention gap introduction in gas chromatography tandem mass spectrometry

Analysis of agrochemical residues in red chilli powder is always considered difficult because of higher matrix interference due to carotenoid pigments and other co-extractives. During the sample preparation, matrix components were co-extracted along with the target compounds leading to frequent source cleaning, changing of liner and column. Efforts were made to improve the chromatographic performance by optimizing sample preparation, choosing matrix-free transitions and introducing a retention gap. The Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) extraction was experimented using different dispersive adsorbents and the purified extract was analyzed by gas chromatography tandem mass spectrometry (GC-MS/MS) system. 84 pesticides under different class were validated and established a limit of quantification of 0.002-0.007 mgkg^-1. The recovery was between 70 and 110% at 0.01, 0.025 and 0.05 mgkg^-1 fortification level and corresponding precision was between 3 and 16% RSD. Suitability of the validated method was established through analysis of market samples of chilli powder for the quantitation of targeted pesticide residues.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-021-05177-3.

Analysis method development and health risk assessment of pesticide and heavy metal residues in Dendrobium Candidum

Herbal medicines that are widely used worldwide are easily contaminated by pesticides and heavy metals, threatening human health. In this study, a modified QuEChERS pre-treatment method combined with HPLC/GC-MS/MS was established for the determination of 24 pesticide residues in Dendrobium candidum. The average recoveries of 24 pesticides in D. candidum were 76.9-110.0% with the relative standard deviation (RSD) of 0.28-11.40%, and their limits of detection (LOD) and limits of quantitation (LOQ) were 0.005-10 and 0.011-22 μg kg^-1, respectively. The results showed that 83.33% of all samples had detected pesticide residues with the concentrations of 0.06-312.83 μg kg^-1. Meanwhile, microwave digestion combined with ICP-MS was used to detect the residues of 8 heavy metals in D. candidum. The average recoveries of 8 heavy metals were 82.7-108.1% with an RSD of 1.4-8.0%, and their LOD and LOQ were 0.0001-0.05 mg kg^-1 and 0.0003-0.2 mg kg^-1, respectively. The results indicated that 8 heavy metals were all detected in all samples, and the highest concentration of Zn was 11.97 mg kg^-1. Furthermore, the health risk assessment showed that the risk of the detected pesticides and heavy metals in samples to humans, specifically to the general population including adults and children, was acceptable.

Optimization and Validation of a Multi-Residue Method for Screening of 126 Pesticide Residues in Herbal Raw Materials and Extracts Used as Ingredients in Ayurvedic Medicines and Dietary Supplements

BACKGROUND

Testing for pesticides levels in herbal products is an important aspect in determining product safety. Plants and its extracts are widely used as ingredients in botanical dietary supplements and traditional medicines. The extracts of plants, especially those prepared out of organic solvents are rich in secondary metabolites and pigments and adequate clean-up is required since the extracts completely dissolve in organic solvents.

OBJECTIVE

The study aims at reporting a multi-residue analytical method for 126 different pesticides in raw material biomass as well as extracts of plants, which are widely used as ingredients in ayurvedic medicines as well as dietary supplements using LC-MSMS and GC-MSMS with a rugged sample preparation technique for accurate results.

METHOD

QuEChERS, GPC, GPC coupled with SPE and LLE coupled with SPE sample preparation methods were compared against each other for suitability to test pesticides in selected herbal raw materials and its alcoholic and aqueous extracts. The standard addition method was used for quantifying the level of pesticides below 10 μg/Kg.

RESULTS

Single laboratory validation for sample preparation involving GPC and SPE resulted linearity in the range of 2.5-500 ng/mL, average intra-day and inter-day precision of 6.6% RSD, and average recovery (spiked at 10 μg/Kg) of 92% for all analytes tested. The method was repeatable with different analysts and days.

CONCLUSIONS

The sample preparation technique combining GPC and SPE as well as LLE and SPE were the most suitable for the selected herbal alcoholic extracts whereas any of the regular techniques involving LLE, SPE, and QuEChERS were suitable for raw material biomass as well as aqueous extracts.

HIGHLIGHTS

The method was found to be capable of determining selected pesticides in the selected matrices at 10 μg/Kg concentration. Provision of recycling solvents used in GPC+SPE method was adopted to make the method environmentally friendly.

Rapid Determination of 21 Chinese Domestically Registered Pesticides in Ginseng Using Cleanup Based on Zirconium-Oxide-Modified Silica and Ultrahigh-Performance Liquid Chromatography-Tandem Mass Spectrometry

In this study, an analytical method was developed for the rapid determination of 21 pesticides used in ginseng cultivation. All pesticides covered by this method have been registered by 2020 in China for use on ginseng. The extracts were cleaned up using zirconium-oxide-modified silica (Z-Sep) and primary secondary amine (PSA). The combination of Z-Sep and PSA provided good recovery for all analytes and the cleanest matrix background out of a number of PSA-based sorbent combinations, as indicated by high-performance liquid chromatography (HPLC) and gas chromatography (GC). Instrumental analysis was completed in 5 min using the ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). The linearity (r > 0.99) for all analytes was satisfactory over the calibration range of 0.002-0.1 μg mL^-1. Intraday recoveries (n = 5) at ginseng-spiked levels of 0.02, 0.05, 0.1, and 1 mg kg^-1 ranged between 72% and 119%, with the corresponding relative standard deviations (RSDs), were less than 19%, while the interday recoveries (n = 15) ranged between 77% and 103%, and RSDs were less than 22%. Limits of quantitation (LOQs) ranged between 0.02 and 0.05 mg kg^-1 for all 21 pesticides. This is a seminal study using Z-Sep for the efficient cleanup of ginseng samples, and it could present a practical method for future monitoring of pesticide residues in ginseng produced in China.

A fluorinated chitosan-based QuEChERS method for simultaneous determination of 20 organophosphorus pesticide residues in ginseng using GC-MS/MS

In this study, a new fluorinated methacrylamide (MACF) was synthesized and evaluated as an adsorbent in the dispersive solid-phase extraction for the effective determination and extraction of 20 organophosphorus pesticides (OPPs) from ginseng samples using the QuEChERS (quick, easy, cheap, effective, rugged, safe) method coupled with GC-MS/MS. The properties of MACF were characterized using Fourier-transform infrared spectroscopy, elemental analysis, and high-resolution ¹⁹ F NMR. MACF, chitosan, primary and secondary amine, octadecylsilane, graphitized carbon black, Z-Sep, Z-Sep⁺ , and EMR-Lipid were compared in terms of extraction efficiency. The best results were obtained when MACF was used. Matrix-matched calibration was employed for quantification. All the OPPs exhibited good linearity (r²  > 0.9969) with the concentration at their respective concentration ranges. The limits of detection were 1.5-3.0 μg/kg, and the limits of quantification were 5.0-10.0 μg/kg. The trueness of the 20 pesticides at four spiked levels ranged from 86.1 to 111.1%, and the relative standard deviation was less than 11.3%. The modified QuEChERS method using MACF as the adsorbent was sensitive, reliable, and cost-effective and could be used for the determination of 20 OPP residues in ginseng.

Determination and Dietary Intake Risk Assessment of Pesticide Residues in Fritillariae Thunbergii Bulbs and Cultivated Soils

BACKGROUND

Pesticide residues in traditional Chinese medicines pose a potential risk to human health. However, little is known about the characteristics of pesticide residues in the fritillariae thunbergii bulbs (FTB).

OBJECTIVE

This study aims to establish a method for the determination of pesticide multi-residues in FTB and then measured their residual levels in the FTB collected from nine cultivation regions.

METHODS

A modified QuEChERS method coupled with GC/UPLC was used to determine the residues of 24 pesticides in the FTB and soil samples.

RESULTS

The recoveries of these pesticides at three concentrations were 72.17-112.48% in the FTB and 70.92-113.74% in the soil with RSD < 11.83%, and the LOD and LOQ ranged from 0.005-10 μg/kg and 0.011-22 μg/kg, respectively. A total of 13 pesticide residues were detected in the FTB samples with the residual levels of 0.0011-509.63 μg/kg, which were all below the referred MRLs in other Chinese herbs or food. Meanwhile, dietary intake risk assessment showed that the risk of pesticide residues in the FTB was acceptable to consumers.

CONCLUSIONS

This study developed a method for the determination of pesticide multi-residues in the FTB and cultivated soil samples, and furthermore the dietary intake risk of pesticide residues in the FTB is safe.

HIGHLIGHTS

A modified QuEChERS method was established for the determination of 24 pesticides in the FTB with high sensitivity, accuracy, and precision.

A comparison of the effectiveness of QuEChERS, FaPEx and a modified QuEChERS method on the determination of organochlorine pesticides in ginseng

This study provides a review of methods used in the determination of organochlorine pesticides (OCPs) in ginseng and compares the effectiveness of three extraction methods (Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS), a modified QuEChERS and a Fast Pesticide Extraction (FaPEx)) in the analyses of 20 OCPs in ginseng root samples. For each method, sample mass, solvent volume and sorbent mass were varied to identify the optimum combination to effectively isolate analytes of interest from the complex sample matrix. Extracts were analyzed using the gas chromatography-μ-electron capture detector (GC-μ-ECD), and confirmatory analyses performed by gas chromatography-tandem-mass spectrometry (GC-MS/MS). Eighteen out of 20 OCPs spiked onto in-house prepared ginseng samples produced acceptable recoveries (51-156%) when extracted using QuEChERS and FaPEx. All 20 analytes, including dichlorodiphenyldichloroethane (p, p'- DDD) and dichlorodiphenyltrichloroethane (o, p'-DDT), produced acceptable recoveries (51-129%) with the use of a modified QuEChERS method. The applicability of the modified QuEChERS method was demonstrated through the analysis of ginseng samples grown in endosulfan-treated soil. The samples were analyzed by both GC-μ-ECD and GC-MS/MS with no significant difference identified in the results of each analytical method. This study highlights the applicability of the modified QuEChERS method, in combination with GC- μ-ECD, to determine organochlorine pesticides in ginseng. This may be especially useful for laboratories in developing countries and less advanced institutions without access to MS/MS instrumentation.

A multi-residue pesticide determination in fatty food commodities by modified QuEChERS approach and gas chromatography-tandem mass spectrometry

A QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) based multi-residue method has been developed and validated for the extraction and determination of pesticides in fatty matrices by gas chromatography tandem mass spectrometry. Extraction and clean-up were performed according to QuEChERS principles widely used for non-fatty matrices, with main difference, a higher solvent/sample- ratio followed by a 6-fold preconcentration step, ensuring good extractability and sensitivity. A validation according to SANTE guidelines was performed using a olive and sunflower oils mixture 1:1, w/w as representative matrix, at 2 concentration levels (5 and 50 µg/kg) targeting 176 GC-amenable pesticides. Most compounds fulfilled the validation criteria, with a limit of quantification of 5 µg/kg for 137 compounds , and of 50 µg/kg for 24 compounds. Afterwards, the method performance was tested in six different fatty matrices with 73-90% of the analytes fulfilling the performance criteria at 5 µg/kg depending on the matrix.

Development and validation of an analysis method for pesticide residues by gas chromatography-tandem mass spectrometry in Daikenchuto

Daikenchuto (DKT) is one of the most widely used “Kampo” in Japan as a representative of herbal medicine. Because DKT is made from a natural product like food, it requires the management of pesticides; therefore, an analysis of residual pesticides in Kampo is required. The World Health Organization (WHO) indicates that pesticide residue analysis by the U.S. Pharmacopeia (USP) is required. USP defines 107 compounds containing organochlorine pesticides and organophosphorus pesticides and their metabolites, which have a high residual risk. Accordingly, to guarantee the safety of herbal medicines according to global standards is a very important issue. In this study, we developed an analytical method for 91 compounds, which are listed in USP, using DKT as the subject. The method could extract pesticides from DKT with acetone, elute pesticides with acetonitrile using a SepPak C18 column (5 g) and with ethyl acetate using a DSC-NH₂ column (2 g), and perform simultaneous analyses by gas chromatography–tandem mass spectrometry (GC–MS/MS). This method, which could quantify 88 compounds, was validated according to USP. A pesticide residue analysis method that meets USP requirements enables the analysis of pesticide residues with a high residue risk and contributes to improving the safety of “Kampo” and other herbal medicines.

A First Tentative for Simultaneous Detection of Fungicides in Model and Real Wines by Microwave Sensor Coupled to Molecularly Imprinted Sol-Gel Polymers

A molecularly imprinted silica (MIS) coupled to a microwave sensor was used to detect three fungicides (iprodione, procymidone and pyrimethanil) present in most French wines. Chemometric methods were applied to interpret the microwave spectra and to correlate microwave signals and fungicide concentrations in a model wine medium, and in white and red Burgundy wines. The developed microwave sensor coupled to an MIS and to its control, a nonimprinted silica (NIS), was successfully applied to detect the three fungicides present in trace levels (ng L^-1) in a model wine. The MIS sensor discriminated the fungicide concentrations better than the NIS sensor. Partial Least Squares models were suitable for determining iprodione in white and red wines. A preliminary method validation was applied to iprodione in the white and red wines. It showed a limit of detection (LOD) lower than 30 ng L^-1 and a recovery percentage between 90 and 110% when the iprodione concentration was higher than the LOD. The determined concentrations were below the authorized level by far.

Pesticide residues in soils planted with Panax notoginseng in south China, and their relationships in Panax notoginseng and soil

In this study, 73 samples from soils planted with Panax notoginseng and six P. notoginseng samples were collected in Yunnan Province to investigate the residual levels of six pesticides and their relationships with P. notoginseng and soil. All six pesticides were detected in the soils planted with P. notoginseng located in three regions of Shilin, Kaiyuan, and Yanshan. The detection frequencies of the pesticides in the soils followed the order: quintozene (100%) > iprodione (96%) > procymidone (69%) > chlorothalonil (51%) > pyrimethanil (49%) > pyraclostrobin (29%). The median concentrations of iprodione, pyraclostrobin, pyrimethanil, quintozene, procymidone, and chlorothalonil were 46.40, 6.4, 3.1, 2.86, 2.69, and 0.24 μg/kg, respectively. The mean concentrations of pesticides in the three regions followed the order: Kaiyuan > Shilin > Yanshan, except for iprodione. Furthermore, the concentrations of pesticide residues in soils in each region followed the order: soils never planted with P. notoginseng < soils previously planted with P. notoginseng < soils currently planted with P. notoginseng. The concentration of chlorothalonil in P. notoginseng followed the order: root > stem > leaf, whereas those of the other five pesticides followed the opposite order: root < stem < leaf. There were significant positive correlations between the mean concentrations of pesticides in P. notoginseng and those in the corresponding soils. These results indicate that the rational application of pesticides in P. notoginseng cultivation would be effective for reducing the accumulation of pesticides in P. notoginseng to protect people from the harmful effects of residual pesticides.

Rapid detection of five pesticide residues using complexes of gold nanoparticle and porphyrin combined with ultraviolet visible spectrum

BACKGROUD

Pesticides are widely used to control insect infestation and weeds in agriculture. However, concerns about the pesticide residues in agricultural products have been raised in recent years because of public interest in health and food quality and safety. Thus, rapid, convenient, and accurate analytical methods for the detection and quantification of pesticides are urgently required.

RESULTS

A nanohybrid system composed of gold nanoparticles (AuNPs) and tetrakis(N-methyl-4-pyridiniumyl) porphyrin (TMPyP) was used as an optical probe for the detection and quantification of five pesticides (Paraquat, Dipterex, Dursban, methyl thiophanate and Cartap). The method is based on the aggregation effect of pesticides on the carboxyl group modified by AuNPs. Subsequently, with the help of particle swarm optimization-optimized sample weighted least squares-support vector machine (PSO-OSWLS-SVM), all the pesticides could be successfully quantified. In addition, partial least squares discriminant analysis (PLS-DA) was applied and the five pesticides were satisfactorily recognized based on data array obtained from the ultraviolet visible (UV-visible) spectra of AuNP-TMPyP complex. Furthermore, the quantitative and qualitative analysis of the five pesticides could be also achieved in the complex real samples, in which all the relative standard deviations (RSDs) were less than 0.3‰ and all the linear absolute correlation coefficients were more than 0.9990. Furthermore, recognition rate of the training set and the prediction set based on multiplicative scatter correction (MSC), or second-order derivative (2nd derivative) UV-visible spectra in PLS-DA model could reach 100%.

CONCLUSION

This method was successfully applied for the rapid and accurate determination of multicomponent pesticide residues in real food samples. © 2020 Society of Chemical Industry.

Transfer of Organochlorine Pesticide Residues during Household and Industrial Processing of Ginseng

Ginseng is an important traditional herbal medicine; however, ginseng root may contain pesticide residues that may cause adverse health effects to consumers. Generally, people are more inclined to take the household- or industrial-processed ginseng products, instead of eating them directly. To investigate the intake of pesticides along with ginseng more specifically, we simulated two household processing methods (boiling and brewing) and two industrial processing methods (ethanol refluxing and boiling combined with resin purification) and then calculated the transfer rates of five organochlorine pesticide (OCP) residues in ginseng. The determination of targeted pesticide residues in ginseng was done by gas chromatography-electron capture detector (GC-ECD), and the confirmation was done by gas chromatography-tandem mass spectrometer (GC-MS/MS). The transfer rates of five OCPs during boiling, brewing, ethanol refluxing, and boiling combined with resin purification were 3.44%–34.43%, 1.47%–38.12%, 34.81%–57.0%, and 0–2.91%, respectively. The transfer rates of the OCPs in water extraction (boiling and brewing) were relatively low and would not increase significantly along with two hours of boiling. The OCPs were concentrated during the ethanol refluxing procedure because of the high transfer rates of the OCPs and the reduction of the weight of products. The boiling combined with resin purification method removed the OCPs most effectively. Different ginseng processing methods resulted in variable transfer rates of pesticides, as well as a diverse exposure risk of pesticides to humans. Consequently, it is necessary to concern about the transfer rates of pesticide residues during ginseng processing.

Selection and characterization of botanical natural products for research studies: a NaPDI center recommended approach

Covering: up to the end of 2018 Dietary supplements, which include botanical (plant-based) natural products, constitute a multi-billion-dollar industry in the US. Regulation and quality control for this industry is an ongoing challenge. While there is general agreement that rigorous scientific studies are needed to evaluate the safety and efficacy of botanical natural products used by consumers, researchers conducting such studies face a unique set of challenges. Botanical natural products are inherently complex mixtures, with composition that differs depending on myriad factors including variability in genetics, cultivation conditions, and processing methods. Unfortunately, many studies of botanical natural products are carried out with poorly characterized study material, such that the results are irreproducible and difficult to interpret. This review provides recommended approaches for addressing the critical questions that researchers must address prior to in vitro or in vivo (including clinical) evaluation of botanical natural products. We describe selection and authentication of botanical material and identification of key biologically active compounds, and compare state-of-the-art methodologies such as untargeted metabolomics with more traditional targeted methods of characterization. The topics are chosen to be of maximal relevance to researchers, and are reviewed critically with commentary as to which approaches are most practical and useful and what common pitfalls should be avoided.

Molecularly imprinted sol-gel polymers for the analysis of iprodione fungicide in wine: Synthesis in green solvent

Iprodione is a fungicide widely used in viticulture in most agricultural countries. It was banned recently in the European community because of its carcinogenic and endocrine disrupting characters. In this work, a cheap analytical method able to monitor iprodione in a white wine was developed. Molecularly imprinted sol-gel polymers (MIS) specific to iprodione and using green solvents were synthesized. An experimental design having the following factors (solvent volume and crosslinker quantity) was used to prepare an optimal MIS. In terms of selectivity, the optimal MIS showed the best partition coefficient towards iprodione in a white wine containing four other competing fungicides (procymidone, pyrimethanil, azoxystrobin and iprovalicarb). A solid phase extraction method using the optimal MIS was optimized and applied to analyse iprodione in a white wine. Low detection and quantification limits were reached 11.7 and 39.1 µg/L respectively.

Development of an ASE-GC-MS/MS method for detecting dinitolmide and its metabolite 3-ANOT in eggs

An accelerated solvent extraction coupled with gas chromatography-tandem mass spectrometry (ASE-GC-MS/MS) method for detecting dinitolmide residue and its metabolite (3-amino-2-methyl-5-nitrobenzamide, 3-ANOT) in eggs was developed and optimized. The samples were extracted using ASE with acetonitrile as the extractant and were purified by passage through a neutral alumina solid-phase extraction column. Then, the samples were analyzed using the GC-MS/MS method. The optimized method parameters were validated according to the requirements set forth by the European Union and the Food and Drug Administration. The average recoveries of dinitolmide and 3-ANOT from eggs (egg white, egg yolk, and whole egg) at the limit of quantification (LOQ), 0.5 maximum residue limit (MRL), 1 MRL, and 2 MRL were 82.74% to 87.49%, the relative standard deviations (RSDs) were less than 4.63%, and the intra-day RSDs and the inter-day RSDs were 2.96% to 5.21% and 3.94% to 6.34%, respectively. The limits of detection and the LOQ were 0.8 to 2.8 μg/kg and 3.0 to 10.0 μg/kg, respectively. The decision limits (CC_α ) were 3001.69 to 3006.48 μg/kg, and the detection capabilities (CC_β ) were 3001.74 to 3005.22 μg/kg. Finally, the new method was successfully applied to the quantitative determination of dinitolmide and 3-ANOT in 50 commercial eggs from local supermarkets.

Quantification and Confirmation of Fifteen Carbamate Pesticide Residues by Multiple Reaction Monitoring and Enhanced Product Ion Scan Modes via LC-MS/MS QTRAP System

In this research, fifteen carbamate pesticide residues were systematically analyzed by ultra-high performance liquid chromatography⁻quadrupole-linear ion trap mass spectrometry on a QTRAP 5500 system in both multiple reaction monitoring (MRM) and enhanced product ion (EPI) scan modes. The carbamate pesticide residues were extracted from a variety of samples by QuEChERS method and separated by a popular reverse phase column (Waters BEH C18). Except for the current conformation criteria including selected ion pairs, retention time and relative intensities from MRM scan mode, the presence of carbamate pesticide residues in diverse samples, especially some doubtful cases, could also be confirmed by the matching of carbamate pesticide spectra via EPI scan mode. Moreover, the fragmentation routes of fifteen carbamates were firstly explained based on the mass spectra obtained by a QTRAP system; the characteristic fragment ion from a neutral loss of CH₃NCO (-57 Da) could be observed. The limits of detection and quantification for fifteen carbamates were 0.2⁻2.0 μg kg-1 and 0.5⁻5.0 μg kg-1, respectively. For the intra- (n = 3) and inter-day (n = 15) precisions, the recoveries of fifteen carbamates from spiked samples ranged from 88.1% to 118.4%, and the coefficients of variation (CVs) were all below 10%. The method was applied to pesticide residues detection in fruit, vegetable and green tea samples taken from local markets, in which carbamates were extensively detected but all below the standard of maximum residue limit.

Determination of Multiresidue Pesticides in Botanical Dietary Supplements Using Gas Chromatography-Triple-Quadrupole Mass Spectrometry (GC-MS/MS)

A simplified sample preparation method in combination with gas chromatography-triple-quadrupole mass spectrometry (GC-MS/MS) analysis was developed and validated for the simultaneous determination of 227 pesticides in green tea, ginseng, gingko leaves, saw palmetto, spearmint, and black pepper samples. The botanical samples were hydrated with water and extracted with acetonitrile, magnesium sulfate, and sodium chloride. The acetonitrile extract was cleaned up using solid phase extraction with carbon-coated alumina/primary-secondary amine with or without C18. Recovery studies using matrix blanks fortified with pesticides at concentrations of 10, 25, 100, and 500 μg/kg resulted in average recoveries of 70-99% and relative standard deviation of 5-13% for all tested botanicals except for black pepper, for which lower recoveries of fortified pesticides were observed. Matrix-matched standard calibration curves revealed good linearity (r(2) > 0.99) across a wide concentration range (1-1000 μg/L). Nine commercially available tea and 23 ginseng samples were analyzed using this method. Results revealed 36 pesticides were detected in the 9 tea samples at concentrations of 2-3500 μg/kg and 61 pesticides were detected in the 23 ginseng samples at concentrations of 1-12500 μg/kg.

A comparative study of primary secondary amino (PSA) and multi-walled carbon nanotubes (MWCNTs) as QuEChERS absorbents for the rapid determination of diazepam and its major metabolites in fish samples by high-performance liquid chromatography-electrospray ionisation-tandem mass spectrometry

BACKGROUND

A simple and fast modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) method is presented for the determination of diazepam and its three major metabolites, nordiazepam, temazepam and oxazepam (benzodiazepines) in fish samples by liquid chromatography-electrospray ionisation-tandem mass spectrometry.

RESULTS

Muscle tissues were extracted with acetonitrile, and then cleaned with primary secondary amino (PSA) adsorbents. The cleanup effect of PSA was compared with that of multi-walled carbon nanotubes (MWCNTs) in term of extraction efficiency. The better results were obtained when PSA was used. The chromatography separation was achieved within 5.0 min on a C18 column. The limit of detection was 0.5 µg kg(-1) and the limit of quantification was 2.5 µg kg(-1). Average recoveries of diazepam and its main metabolites were in the range of 88.5-110.1%, with a relative standard deviation lower than 10.0%.

CONCLUSION

The proposed method for fish samples gives good recoveries, linearity, precision and accuracy.

Two-step dispersive-solid phase extraction strategy for pesticide multiresidue analysis in a chlorophyll-containing matrix by gas chromatography-tandem mass spectrometry

Two-step dispersive-solid phase extraction strategy for the cleanup of QuEChERS extracts in multiresidue analysis of current-use pesticides in a chlorophyll-containing matrix was evaluated and is reported for the first time. The proposed approach combines two sequential steps of dispersive-solid phase extraction (d-SPE) to reduce matrix co-extractives. In the first step, primary secondary amine (PSA) together with a new type of sorbent, known as ChloroFiltr, was employed. This was followed by a second step of d-SPE using octadecyl (C18) and graphitized carbon black (GCB). Also, new zirconium dioxide-based sorbents (Z-Sep+ and Z-Sep/C18) were evaluated but the use of GCB/C18 provided the highest pesticide coverage with recoveries in the range of 70-120% from spiked green soybean samples. The final extracts were analyzed by gas chromatography coupled to tandem mass spectrometry (GC-MS/MS). The overall recoveries at three spiking levels of 0.01, 0.05 and 0.2 mg kg(-1) were 96±15%, 93±13% and 92±13% with relative standard deviations of 10±7%, 9±5%, and 11±5%, respectively. The proposed method provided matrix effect <20% for 77% of the target compounds, which may be considered as negligible because such variability is closed to the accepted repeatability. For the rest of 8 and 15% of the compounds, the matrix effect was 20-30% and >30%, respectively. The developed method was successfully applied to study dissipation patterns of pesticides applied to soybean in experimental plot trials, thus contributing to establish safe and proper use of pesticides by extension of authorization on minor crops in Poland.

Sensitive determination of mixtures of neonicotinoid and fungicide residues in pollen and single bumblebees using a scaled down QuEChERS method for exposure assessment

To accurately estimate exposure of bees to pesticides, analytical methods are needed to enable quantification of nanogram/gram (ng/g) levels of contaminants in small samples of pollen or the individual insects. A modified QuEChERS extraction method coupled with ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) analysis was tested to quantify residues of 19 commonly used neonicotinoids and fungicides and the synergist, piperonyl butoxide, in 100 mg samples of pollen and in samples of individual bumblebees (Bombus terrestris). Final recoveries ranged from 71 to 102 % for most compounds with a repeatability of below 20 % for both pollen and bumblebee extracts spiked at 5 and 40 ng/g. The method enables the detection of all compounds at sub-ng/g levels in both matrices and the method detection limits (MDL) ranged from 0.01 to 0.84 ng/g in pollen and 0.01 to 0.96 ng/g in individual bumblebees. Using this method, mixtures of neonicotinoids (thiamethoxam, clothianidin, imidacloprid and thiacloprid) and fungicides (carbendazim, spiroxamine, boscalid, tebuconazole, prochloraz, metconazole, fluoxastrobin, pyraclostrobin and trifloxystrobin) were detected in pollens of field bean, strawberry and raspberry at concentrations ranging from <MDL to 67 ng/g for neonicotinoids and from <MDL to 14 ng/g for fungicides. In bumblebees, the insecticides thiamethoxam and thiacloprid were present at concentrations >MDL, and in some bees, the fungicides carbendazim, boscalid, tebuconazole, flusilazole and metconazole were present at concentrations between 0.80 to 30 ng/g. This new method allows the analysis of mixtures of neonicotinoids and fungicides at trace levels in small quantities of pollen and individual bumblebees and thus will facilitate exposure assessment studies.

Qualitative and quantitative analysis on aroma characteristics of ginseng at different ages using E-nose and GC-MS combined with chemometrics

Aroma profiles of ginseng samples at different ages were investigated using electronic nose (E-nose) and GC-MS techniques combined with chemometrics analysis. The bioactive ginsenoside and volatile oil content increased with age. E-nose performed well in the qualitative analyses. Both Principal Component Analysis (PCA) and Discriminant Functions Analysis (DFA) performed well when used to analyze ginseng samples, with the first two principal components (PCs) explaining 85.51% and the first two factors explaining 95.51% of the variations. Hierarchical Cluster Analysis (HCA) successfully clustered the different types of ginsengs into four groups. A total of 91 volatile constituents were identified. 50 of them were calculated and compared using GC-MS. The main fragrance ingredients were terpenes and alcohols, followed by aromatics and ester. The changes in terpenes, alcohols, aromatics, esters, and acids during the growth year once again confirmed the dominant role of terpenes. The Partial Least Squares (PLS) loading plot of gas sensors and aroma ingredients indicated that particular sensors were closely related to terpenes. The scores plot indicated that terpenes and its corresponding sensors contributed the most in grouping. As regards to quantitative analyze, 7 constituent of terpenes could be accurately explained and predicted by using gas sensors in PLS models. In predicting ginseng age using Back Propagation-Artificial Neural Networks (BP-ANN), E-nose data was found to predict more accurately than GC-MS data. E-nose measurement may be a potential method for determining ginseng age. The combination of GC-MS can help explain the hidden correlation between sensors and fragrance ingredients from two different viewpoints.

Organochlorine pesticides and pyrethroids in Chinese tea by screening and confirmatory detection using GC-NCI-MS and GC-MS/MS

One hundred and one tea samples including green tea, dark tea, scented tea, black tea, and oolong tea were screened and confirmed for the contamination of 31 organochlorine pesticides (OCPs) and 19 pyrethroids (PYs) by gas chromatography-negative chemical ionization-mass spectrometry (GC-NCI-MS) and gas chromatography-tandem mass spectrometry (GC-MS/MS). 50 pesticides, 3 deuterium-labeled PYs, and 24 (13)C-labeled OCPs were separated well with the limits of detection (LODs) ranging from 0.02 to 4.5 μg/kg for GC-NCI-MS, and the positive samples were verified by GC-MS/MS with LODs of 0.1-5.0 μg/kg. High detection rates for some PYs, such as 63.4% for bifenthrin (not detected (ND)-3.848 mg/kg), 55.4% for λ-cyhalothrin (ND-3.244 mg/kg), 46.5% for cypermethrin (ND-0.499 mg/kg), and 24.8% for fenvalerate (ND-0.217 mg/kg), were found in the 101 tea samples. Endosulfan, DDTs, HCHs, and heptachlor, the persistent OCPs, were frequently detected with rates of 63.4% (ND-1.802 mg/kg), 56.4% (ND-0.411 mg/kg), 24.8% (ND-0.377 mg/kg), and 15.8% (ND-0.100 mg/kg), respectively.

Simultaneous analysis of endosulfan, chlorpyrifos, and their metabolites in natural soil and water samples using gas chromatography-tandem mass spectrometry

Analysis of endosulfan, chlorpyrifos, and their nonpolar metabolites in extracts from environmental aqueous and soil samples was performed using a gas chromatography-tandem mass spectrometry (GC-MS/MS) technique. Full-scan GC-MS analysis showed poor sensitivity for some of the metabolites (endodiol and endosulfan ether). A multisegment MS/MS method was developed and MS/MS parameter isolation time, excitation time, excitation voltage, and maximum excitation energy were optimized for chosen precursor ions to enhance selectivity and sensitivity of the analysis. The use of MS/MS with optimized parameters quantified analytes with significantly higher accuracy, and detection limits were lowered to ~1/6th compared with the full-scan method. Co-eluting compounds, chlorpyrifos and chlorpyrifos oxon, were also analyzed successfully in the MS/MS mode by choosing exclusive precursor ions. Analysis of soil and water phase samples from contaminated soil slurry bioreactors showed that the MS/MS method could provide more reliable estimates of these pesticide and metabolites (especially those present in low concentrations) by annulling interferences from soil organic matter.

Rapid determination of residual pesticides in tobacco by the quick, easy, cheap, effective, rugged, and safe sample pretreatment method coupled with LC-MS

A quick, easy, cheap, effective, rugged, and safe (QuEChERS) sample pretreatment method coupled with LC-MS was developed for the determination of 11 pesticides in tobacco. Sample pretreatment parameters and instrumental parameters of LC-MS were investigated, and the optimal conditions were selected. Under the optimized conditions, the 11 pesticides were detected simultaneously with a good linear relationship (r(2) = 0.9993-0.9999) and high precisions (less than 5% of the RSD of peak areas). The LODs were in the range of 0.1-5.0 μg/L. Compared with SPE clean-up, QuEChERS greatly simplified the sample pretreatment with simple solvent extraction system. After QuEChERS pretreatment, no serious matrix effects were observed. Used for the analysis of real samples, metalaxyl was found in cigarette and tobacco samples at 63.47 and 132.27 ng/g, respectively. The recoveries for 11 pesticides were in the range of 70.03-118.69%, and RSDs were less than 10%. The proposed method is simple, low cost, and has good reproducibility.

Recent methodology in ginseng analysis

As much as the popularity of ginseng in herbal prescriptions or remedies, ginseng has become the focus of research in many scientific fields. Analytical methodologies for ginseng, referred to as ginseng analysis hereafter, have been developed for bioactive component discovery, phytochemical profiling, quality control, and pharmacokinetic studies. This review summarizes the most recent advances in ginseng analysis in the past half-decade including emerging techniques and analytical trends. Ginseng analysis includes all of the leading analytical tools and serves as a representative model for the analytical research of herbal medicines.

A robust GC-MS/MS method for the determination of chlorothalonil in fruits and vegetables

Chlorothalonil is a non-systemic fungicide that is easily degraded in contact with plants and soil or even by the effect of light and pH. A method for the determination of chlorothalonil in courgettes, strawberries, oranges, leeks and tomato by solvent extraction followed by GC-MS/MS with a triple quadrupole analyser was developed. The causes of chlorothalonil degradation during sample treatment were studied and minimised. The final method was based on extraction with acetone in the presence of 0.1 M EDTA sodium salt solution, and clean-up by SPE using OASIS HLB cartridges. Isotope-labelled hexachlorobenzene (HCB-(13)C(6)) was added as an internal standard to the SPE extracts before analysis by GC-MS/MS (EI) (QqQ) analysis in order to correct for instrumental deviations. Quantification was performed by matrix-matched standard calibration using relative responses to the internal standard. Two MS/MS transitions were used for mass spectrometric determination of chlorothalonil to ensure reliable quantification and confirmation. The method was validated using blank samples (for all matrices) spiked at two levels. Recoveries between 77% and 110% and an RSD below 20% were obtained for 0.1 and 0.01 mg kg(-1) spiking levels (n = 5). The validated method was applied to treated and untreated samples collected from an experimental field where a chlorothalonil formulated was applied.

Multiresidue pesticide analysis of dried botanical dietary supplements using an automated dispersive SPE cleanup for QuEChERS and high-performance liquid chromatography-tandem mass spectrometry

An automated dispersive solid phase extraction (dSPE) cleanup procedure as part of the Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) method, coupled with liquid chromatography-tandem mass spectrometry using electrospray ionization in positive mode, was used for the simultaneous analysis of 236 pesticides in three dried powdered botanical dietary supplements (ginseng, saw palmetto, and gingko biloba). The procedure involved extraction of the dried powdered botanical samples with salt-out acetonitrile/water extraction using anhydrous magnesium sulfate and sodium chloride, followed by an automated dSPE cleanup using a mixture of octadodecyl- (C18) and primary-secondary amine (PSA)-linked silica sorbents and anhydrous MgSO4 and online LC-MS/MS analysis. Dynamic multiple-reaction monitoring (DMRM) based on the collection of two precursor-to-product ion transitions with their retention time windows was used for all of the targeted pesticides and the internal standard. Matrix-matched calibration standards were used for quantitation, and standard calibration curves showed linearity (r(2) > 0.99) across a concentration range of 0.2-400 ng/mL for the majority of the 236 pesticides evaluated in the three botanical matrices. Mean recoveries (average %RSD, n = 4) were 91 (6), 93 (4), 96 (3), and 99 (3)% for ginseng, 101 (9), 98 (6), 99 (4), and 102 (3)% for gingko biloba, and 100 (9), 98 (6), 96 (4), and 96 (3)% for saw palmetto at fortification concentrations of 25, 100, 250, and 500 μg/kg, respectively. The geometric mean matrix-dependent instrument detection limits were 0.17, 0.09, and 0.14 μg/kg on the basis of the studies of 236 pesticides tested in ginseng roots, gingko biloba leaves, and saw palmetto berries, respectively. The method was used to analyze incurred ginseng samples that contained thermally labile pesticides with a concentration range of 2-200 μg/kg, indicating different classes of pesticides are being applied to these botanicals other than the traditional pesticides that are commonly used and analyzed by gas chromatography techniques. The method demonstrates the use of an automated cleanup procedure and the LC-MS/MS detection of multiple pesticide residues in dried, powdered botanical dietary supplements.