Analysis of Veterinary Drug and Pesticide Residues Using the Ethyl Acetate Multiclass/Multiresidue Method in Milk by Liquid Chromatography-Tandem Mass Spectrometry

Detection of 11 carbamate pesticide residues in raw and pasteurized camel milk samples using liquid chromatography tandem mass spectrometry: Method development, method validation, and health risk assessment

This study aimed to use ultra-high-performance liquid chromatography coupled to a triple-quadrupole mass spectrometer to detect 11 carbamate pesticide residues in raw and pasteurized camel milk samples collected from the United Arab Emirates. A method was developed and validated by evaluating limits of detection, limits of quantitation, linearity, extraction recovery, repeatability, intermediate precision, and matrix effect. Due to the high protein and fat content in camel milk, a sample preparation step was necessary to avoid potential interference during analysis. For this purpose, 5 different liquid-liquid extraction techniques were evaluated to determine their efficiency in extracting carbamate pesticides from camel milk. The established method demonstrated high accuracy and precision. The matrix effect for all carbamate pesticides was observed to fall within the soft range, indicating its negligible effect. Remarkably, detection limits for all carbamates were as low as 0.01 μg/kg. Additionally, the coefficients of determination were >0.998, demonstrating excellent linearity. A total of 17 camel milk samples were analyzed, and only one sample was found to be free from any carbamate residues. The remaining 16 samples contained at least one carbamate residue, yet all detected concentrations were below the recommended maximum residue limits set by Codex Alimentarius and the European Union pesticide databases. Nonetheless, it is worth noting that the detected levels of ethiofencarb in 3 samples were close to the borderline of the maximum residue limit. To assess the health risk for consumers of camel milk, the hazard index values of carbofuran, carbaryl, and propoxur were calculated. The hazard index values for these 3 carbamate pesticides were all below 1, indicating that camel milk consumers are not at risk from these residues.

Establishment of a modified QuEChERS extraction and liquid chromatography-tandem mass spectrometry method for multiple pesticide residues followed by determination of the residue levels and exposure assessment in livestock urine

The establishment of an analytical method for pesticide residues in livestock urine can realize the real-time monitoring of pesticide pollution in livestock breeding. In this study, a novel method was developed for the determination of 106 pesticide residues in livestock urine based on a modified QuEChERS extraction and liquid chromatography-tandem mass spectrometry. Acetonitrile was used to extract target analytes through acidic and alkaline switching of the sample environment. The purification effect of captiva EMR-Lipid on samples was investigated. Three kinds of materials, C18, polar enhanced polymer (PEP), N-propylethylenediamine (PSA), were selected from 20 kinds of materials as adsorbents for QuEChERS. A mass analysis was carried out using simultaneous scanning in both positive and negative ion mode and multiple reaction monitoring mode. All analytes showed good linearity, with correlation coefficients (R2) greater than 0.9923; their limits of quantification were 0.02-1.95 ng/mL. The average recoveries at low, medium, and high spiked levels were in the range of 70.1 %-117.3 %, with intra-day precision ranging from 3.4 % to 16.9 % and inter-day precision ranging from 4.0 % to 19.3 %. The established analytical method was used to analyze the pesticide residue in swine urine and bovine urine collected from farms in Yining, Xinjiang, China. A total of 8 pesticides were detected, and the residue ranged from less than the limit of quantitation to 22.4 ng/mL. The top three pesticides with the highest detection frequency were clothianidin, thiamethoxam, and dinotefuran. The exposure assessment based on the monitored pesticide residue concentration levels showed that the detected pesticides could pose little risk to cattle and pigs.

Evaluation of Antibiotics Residues in Milk and Meat Using Different Analytical Methods

Veterinary drugs are pharmacologically and biologically active chemical agents. At present, veterinary drugs are extensively used to prevent and treat animal diseases, to promote animal growth, and to improve the conversion rate of feed. However, the use of veterinary drugs in food-producing animals may leave residues of the parent compounds and/or their metabolites in food products resulting in harmful effects on humans. To ensure food safety, sensitive and effective analytical methods have been developing rapidly. This review describes sample extraction and cleanup methods, and different analytical techniques are used for the determination of veterinary drug residues in milk and meat. Sample extraction methods, such as solvent extraction, liquid-liquid extraction, and cleanup methods such as dispersive solid-phase extraction and immunoaffinity chromatography, were summarized. Different types of analytical methods such as microbial, immunological, biosensor, thin layer chromatography, high-performance liquid chromatography, and liquid chromatography-tandem mass spectrometry were discussed for the analysis of veterinary drug residues in animal-derived foods. Liquid chromatography-tandem mass spectrometry is the most widely used analytical technique for the determination of antibiotic drug residues. This is due to the powerful separation of LC and accurate identification of MS, and LC-MS/MS is more popular in the analysis of veterinary drug residues.

Accurate Determination of Pesticide Residues in Milk by Sonication-QuEChERS Extraction and LC-LTQ/Orbitrap Mass Spectrometry

A modified, quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction procedure combined with sonication and Ultra-High Performance Liquid Chromatography–Orbitrap-Mass Spectrometry (UHPLC–Orbitrap-MS) was developed as a sensitive and reliable methodology for the determination of multiclass pesticides in full-fat milk. Different amounts of EMR-lipid sorbent were assayed for the cleanup step in order to achieve both acceptably high recoveries and low co-extractives in the final extracts. Accurate mass measurements of the analyte’s pseudo-molecular ions and tandem MS fragmentation were used to quantify and identify the target pesticides. Analytical performance characteristics of the method, such as linearity, recovery, precision, the limit of detection (LOD) and quantification (LOQ), matrix effects (ME), and expanded uncertainty, have been determined for method validation fulfilling all criteria for its use as a validated routine method. The method was successfully applied to real samples (by local farms and commercial), revealing the presence of carbendazim in one milk sample at a concentration level below the maximum residue limits.

Determination of veterinary drug residues, mycotoxins, and pesticide residues in bovine milk by liquid chromatography electrospray ionisation –tandem mass spectrometry

Introduction

Multi-class and multi-residue analyses are very complex procedures because of the physico-chemical properties of veterinary drug residues and other contaminants. The purpose of the study was to develop an analytical method for the sensitive determination of 69 analytes in bovine milk by liquid chromatography electrospray ionisation–tandem mass spectrometry.

Material and Methods

Antimicrobial, anabolic hormone, lactone, β-agonist, mycotoxin and pesticide residues were analysed in 120 raw milk samples from different dairy farms in North Macedonia. Stable isotopically labelled internal standards were used to facilitate effective quantification of the analytes.

Results

The linear regression coefficients were higher than 0.99, the limits of detection ranged from 0.0036 to 47.94 μg/L, and the limits of quantification ranged from 0.053 to 59.43 μg/L. The decision limit values ranged from 0.062 to 211.32 μg/L and the detection capability from 0.080 to 233.71 μg/L. Average recoveries of the analytes spiked in raw milk were in the range of 70.83% to 109%, intra-day coefficient of variation (CV) values from 2.41% to 22.29%, and inter-day CV values from 3.48% to 23.91%. The method was successfully applied in the testing of bovine milk samples. In five samples residues were detected. They were sulfadimethoxine (in two samples), enrofloxacin, tetracycline and oxytetracycline and were at concentrations below the EU maximum residue limit.

Conclusion

The method is useful for routine testing for this group of chemical hazards in bovine milk.

Development of a High-Throughput Screening Analysis for 195 Pesticides in Raw Milk by Modified QuEChERS Sample Preparation and Liquid Chromatography Quadrupole Time-of-Flight Mass Spectrometry

This study aimed to develop a simple, high-throughput method based on modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) followed by liquid chromatography quadrupole time-of-flight mass spectrometry (LC-Q-TOF/MS) for the rapid determination of multi-class pesticide residues in raw milk. With acidified acetonitrile as the extraction solvent, the raw milk samples were pretreated with the modified QuEChERS method, including extraction, salting-out, freezing, and clean-up processes. The target pesticides were acquired in a positive ion electrospray ionization mode and an All ions MS/MS mode. The developed method was validated, and good performing characteristics were achieved. The screening detection limits (SDL) and limits of quantitation (LOQ) for all the pesticides ranged within 0.1–20 and 0.1–50 μg/kg, respectively. The recoveries of all analytes ranged from 70.0% to 120.0% at three spiked levels (1 × LOQ, 2 × LOQ, and 10 × LOQ), with relative standard deviations less than 20.0%. The coefficient of determination was greater than 0.99 within the calibration linearity range for the detected 195 pesticides. The method proved the simple, rapid, high throughput screening and quantitative analysis of pesticide residues in raw milk.

Simultaneous determination of triazine herbicides and their metabolites in shellfish by HPLC-MS/MS combined with Q/E-Orbitrap HRMS

Triazine herbicides are used extensively in agriculture and aquaculture worldwide because of their broad effectiveness in weed control. However, after they are discharged into the sea, they seriously contaminate aquatic ecosystems and threaten aquatic organisms, especially shellfish. Currently, there are no established methods for the detection and confirmation of triazine herbicides and their metabolites in biological matrixes. Hence, the food safety of aquatic products cannot be accurately evaluated, which creates a technical barrier against international aquatic product trade. In this study, for the first time, a method was developed for the analysis and confirmation of seven triazine herbicides and 13 metabolites in shellfish, based on alkaline acetonitrile extraction and neutral Al₂O₃ cartridge purification coupled with internal standard calibration. Specifically, quantitative and qualitative analysis was conducted using high-performance liquid chromatography-triple quadrupole mass spectrometry (HPLC-MS/MS), and accurate identification was carried out by quadrupole orbitrap high-resolution mass spectrometry (Q/E Orbitrap HRMS). The results showed that target analytes demonstrated good linearity within the corresponding range (R² > 0.995). The limit of detection and limit of quantitation of the proposed method were 0.1 and 0.3 μg/kg, respectively. The average recoveries of analytes were between 70.0% and 120% when spiked at three levels with blank oyster (Crassostrea gigas) as the matrix, and the relative standard deviations (RSDs) were all less than 12% (n=6). The proposed method was successfully applied for the detection of triazine herbicide residues in oyster samples during actual breeding, and the presence of DIP, HP, DEHA, and other metabolites in positive samples was confirmed by Q/E Orbitrap HRMS. This method exhibits high accuracy, high sensitivity, and good reproducibility. It has promising application prospects in the field of hazard analysis and the positive identification of aquatic products.

Assessment of various veterinary drug residues in animal originated food products

The veterinary drugs are broad-spectrum antibacterial antibiotics; it uses to cure the animal disease. Many countries have banned veterinary drug residues like nitrofurans metabolites, chloramphenicol. However, the people were administrated veterinary drugs to animals as illegal to increase the milk production in animals for economic benefit. The results of illegally use of veterinary drugs remain as a residue in animal product like milk and it is very harmful to whom consume it cause cancer and allergic for human being which has entered the concern among milk consumers. To control illegal use of veterinary drugs, the government of India has restricted its use in animals. For the identification and confirmation of veterinary drug residues in animal products, analytical techniques such as liquid chromatography and mass spectrometry are available. These are very sophisticated equipments which are available nowadays and their methodologies for the analytical method validation are described by European commission 2002/657/EC. The use of veterinary drugs is a big challenge to effectively identify and authorization of their use. There are so many analytical techniques are using very effectively and taking very less time to protect the consumers from their adverse effects. These techniques take very less time to identify more groups of compounds such as tetracycline, sulfonamides, anthelmintic, and macrolides in single multi-residue method. These methods having validation parameters include system precision, calibration curve, accuracy, limit of detection, and quantification. Therefore, improvement in the existing technologies and accessibility of new screening methodologies will give opportunities for automation that helps in obtaining the results in very less time and improved sensitivity and specificity which contribute to better safety assurance, standard, and quality of various food products of animal origin.

Possible food safety hazards of ready-to-eat raw fish containing product (sushi, sashimi)

It is undeniable that with the popularity of sushi and sashimi over the last decade the consumption of raw fish has extremely increased. Raw fish is very appreciated worldwide and has become a major component of human diet because of its fine taste and nutritional properties. Possible hazards concerning fish safety and quality are classified as biological and chemical hazards. They are contaminants that often accumulate in edible tissue of fish and transmit to humans via the food chain affecting the consumer's health. Although their concentration in fish and fishery products are found at non-alarming level of a daily basis period, they induce hazardous outcome on human health due to long and continuous consumption of raw fish. Regular sushi and sashimi eaters have to be aware of the contaminants found in the other components of their dish that often add up to acceptable residue limits found in fish. Hence, there is the urge for effective analytical methods to be developed as well as stricter regulations to be put in force between countries to monitor the safety and quality of fish for the interest of public health.

QuEChERS - Fundamentals, relevant improvements, applications and future trends

The Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) method is a simple and straightforward extraction technique involving an initial partitioning followed by an extract clean-up using dispersive solid-phase extraction (d-SPE). Originally, the QuEChERS approach was developed for recovering pesticide residues from fruits and vegetables, but rapidly gained popularity in the comprehensive isolation of analytes from different matrices. According to PubMed, since its development in 2003 up to November 2018, about 1360 papers have been published reporting QuEChERS as extraction method. Several papers have reported different improvements and modifications to the original QuEChERS protocol to ensure more efficient extractions of pH-dependent analytes and to minimize the degradation of labile analytes. This analytical approach shows several advantages over traditional extraction techniques, requiring low sample and solvent volumes, as well as less time for sample preparation. Furthermore, most of the published studies show that the QuEChERS protocol provides higher recovery rate and a better analytical performance than conventional extraction procedures. This review proposes an updated overview of the most recent developments and applications of QuEChERS beyond its original application to pesticides, mycotoxins, veterinary drugs and pharmaceuticals, forensic analysis, drugs of abuse and environmental contaminants. Their pros and cons will be discussed, considering the factors influencing the extraction efficiency. Whenever possible, the performance of the QuEChERS is compared to other extraction approaches. In addition to the evolution of this technique, changes and improvements to the original method are discussed.

Simultaneous determination and risk assessment of metalaxyl and azoxystrobin in potato by liquid chromatography with tandem mass spectrometry

A liquid chromatography with tandem mass spectrometry method was developed and validated to simultaneously determine metalaxyl and azoxystrobin in soil, potato, and potato foliage samples. The samples were extracted by 20 mL of acetonitrile and purified with dispersive solid-phase extraction using octadecyl silane as sorbent. The method showed good linearity (determination coefficients ≥ 0.9926) for metalaxyl (2.5-500 ng/mL) and azoxystrobin (5-1000 ng/mL). The limits of detection and quantification for both fungicides were 1.5-20 μg/kg. The average recoveries in soil, potato, and potato foliage were 83.07-92.87% for metalaxyl and 82.71-98.53% for azoxystrobin. The intra- and inter-day relative standard deviations were all less than 9%. The method was successfully applied on the residual analysis of metalaxyl and azoxystrobin in field trial samples. The results showed that the concentrations of metalaxyl and azoxystrobin in potato samples collected from Guizhou and Hunan were below 50 and 100 μg/kg (maximum residue limit set by China), respectively, at 5 days after the last application. When following the recommended application manual, metalaxyl and azoxystrobin do not present health concerns to the population because the risk quotients are far below 100%. All the above data could help and promote the safe and proper use of metalaxyl and azoxystrobin in potato.