QuEChERS-HPLC-DAD method for sulphonamides in chicken breast

Development, Optimization, and Validation of Forensic Analytical Method for Quantification of Anticholinesterase Pesticides in Biological Matrices from Suspected Cases of Animal Poisoning

Anticholinesterase pesticides are a main cause of the intentional or accidental poisoning of animals. Anticholinesterases include several substances that cause the overstimulation of both central and peripheral acetylcholine-dependent neurotransmission. Forensic analyses of poisoning cases require high levels of expertise, are costly, and often do not provide reliable quantitative information for unambiguous conclusions. The purpose of the present study was to develop and validate a method of high-performance liquid chromatography with diode array detector (HPLC−DAD) for the identification and quantitation of n-methyl carbamates, organophosphates and respective metabolites from biological samples of animals that were suspected of poisoning. HPLC−DAD is reliable, fast, simplistic and cost-effective. The method was validated for biological samples obtained from stomach contents, liver, vitreous humor and blood from four different animal species. The validation of the method was achieved using the following analytical parameters: linearity, precision, accuracy, selectivity, recovery, and matrix effect. The method showed linearity at the range of 25−500 μg/mL, and the correlation coefficient (r2) values were >0.99 for all matrices. Precision and accuracy were determined by the (a) coefficient of variation (CV), (b) relative standard deviation low-quality control (LQC), (c) medium-quality control (QCM), and (d) high-quality control (QCA). The indicated parameters were all less than 15%. The recovery of analytes ranged from 31 to 71%. The analysis of results showed no significant interfering peaks due to common xenobiotics or matrix effects. The abovementioned method was used to positively identify pesticide analytes in 44 of the 51 animal samples that were suspected of poisoning, demonstrating its usefulness as a forensic tool.

Detection and quantification of multiclass antibiotic residues in poultry products using solid-phase extraction and high-performance liquid chromatography with diode array detection

This article describes the initial study on the simultaneous determination of multiclass antibiotic residues in imported and local frozen poultry specimens, including turkey gizzard and muscle tissues, and chicken muscle tissues, commonly consumed in Ogun State, Nigeria. Minced tissues were treated with phosphate buffer adjusted to pH 7 that was cleaned using C18 SPE-column (Supelclean™) cartridge. For the determination of six antibiotic residues including fluoroquinolones, sulfonamides, and macrolides, a solid-phase extraction method was used, followed by extract analysis using high-performance liquid chromatography-diode array detection (HPLC-DAD). The coefficient of determination (R2) for the external standards for all the analytes ranged between 0.963 and 0.999. The limit of detection (LOD) and quantification (LOQ) ranged between 5.37 - 55.4 μg/kg, and 17.9-185 μg/kg, respectively. Enrofloxacin, sulfadimethoxine, sulfamerazine, and tylosin showed high concentration levels in the frozen poultry beyond acceptable maximum residue limits (MRLs). The six drugs considered in this study were present at higher concentrations in domestic chicken tissues than the permissible level. This suggests that farmers do not observe the cessation period before poultry birds previously treated with antibiotics are sold to consumers thus exposing them to potentially hazardous antibiotic residues.

Toxicological analyses: analytical method validation for prevention or diagnosis

The need for reliable results in Toxicological Analysis is recognized and required worldwide. The analytical validation ensures that a method will provide trustworthy information about a particular sample when applied in accordance with a predefined protocol, being able to determine a specific analyte at a distinct concentration range for a well-defined purpose. The driving force for developing method validation for bioanalytical projects comes from the regulatory agencies. Thus, the approach of this work is to present theoretical and practical aspects of method validation based on the analysis objective, whether for prevention or diagnosis. Although various legislative bodies accept differing interpretations of requirements for validation, the process for applying validation criteria should be adaptable for each scientific intent or analytical purpose.

Simultaneous analysis of multiclass antibiotic residues in complex environmental matrices by liquid chromatography with tandem quadrupole mass spectrometry

A simultaneous extraction and cleanup method was optimized and validated for the determination of 40 antibiotics from cephalosporin, fluoroquinolone, lincosamide, macrolide, nitroimidazole, quinolone, sulfonamide and tetracycline groups in sediments by liquid chromatography with tandem quadrupole mass spectrometry (LC-MS/MS). The method involved hydration of freeze-dried sediment sample (2.0 g) with 2.5 ml of 0.1 M Na-EDTA McIlvaine buffer and extraction with 5 ml of MeOH and MeCN (1:3 v/v) followed by dispersive solid phase extraction by using 100 mg mix of C18 and PSA (1:2 w/w) and 50 mg MgSO₄ prior to LC-MS/MS analysis. The method was validated for 10, 20, 50 and 100 µg/kg spiking levels by using blank sediment sample obtained from a drinking water reservoir according to the guidelines of European Commission Decision (2002) 2002/657/EC. The method produced clean extracts with generally low matrix effect during LC-MS/MS analysis. The mean recoveries ranged between 24-162%, 48-151%, 51-159%, and 50-149% for 10, 20, 50 and 100 µg/kg spiking levels, respectively, with acceptable precision. The analytical method was sensitive enough to achieve 0.01-34.3 µg/kg and 0.03-115 µg/kg limits of detection and quantitation, respectively. The scope of the method was demonstrated by analyzing complex solid environmental matrices (chicken manure, swine manure, poultry feed and soil) spiked at 10, 20, 50 and 100 µg/kg levels. The method was also applied for the antibiotic analysis in samples with incurred residues. Different matrices in the order of the magnitude as sediments < poultry feed < swine manure < soil < chicken manure were detected with the residues of fluoroquinolone, macrolide, sulfonamide and tetracycline antibiotics.

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.

Determination of antibiotic residues in frozen poultry by a solid-phase dispersion method using liquid chromatography-triple quadrupole mass spectrometry

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Twenty-two antibiotic residues quantitatively detected in illegally imported poultry tissues.

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Macrolides, roxithromycin and tylosin were mostly detected in all tissue samples.

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Maximum concentration above MRL recorded for roxithromycin and tylosin with 57.14% and 14.29% violation.

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Sulfonamides indicated high detection frequency in turkey muscle tissues (46.15%).

Importation of poultry produce into Nigeria through its land borders has heightened, notwithstanding the government’s ban on such products. This study examined imported frozen poultry products for antibiotic residues considering their health implications. A solid-phase extraction method using liquid chromatography-tandem mass spectrometry in the positive and negative electrospray ionisation and the multiple reaction monitoring modes were employed. The antibiotics were extracted with acetonitrile-dichloromethane. Chromatographic separation was on Waters Acquity UPLC® BEH C18 column with acetonitrile, and water gradient and the antibiotics analysed using Electrospray positive ionisation polarity switch in a single run of fourteen minutes. Residues of nineteen (19) antibiotics were found in the three different matrices at different levels with varying detection frequencies ranging between 2 and 4% (sulfamoxole, penicillin-G, albendazole and phebendazole) and 14–54% for all the other antibiotics. The highest number of violative samples was found in the turkey gizzard and chicken muscle. Sulfixosazole had the highest percentage violation of 80.00% in turkey gizzard while sulfamethoxazole, notwithstanding its lower frequency in chicken muscle had highest maximum concentration and 100% violation. The presence of these drugs, however, does not pose any immediate health risk.

Application of QuEChERS for Determining Xenobiotics in Foods of Animal Origin

The use of pesticides and veterinary drugs results in the appearance of residues of xenobiotics in foods. Thus, several methods have been developed for monitoring them; however, most are tedious and expensive. By contrast, the QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) methodology involves a microextraction that yields small samples and has been applied for the analysis of various xenobiotics including pesticides, antibiotics, and mycotoxins. QuEChERS has shown advantages over other techniques including fast sample preparation, reduced needs for reagents and labware, and versatility. This approach allows the simultaneous determination of pesticides with various polarities and volatilities and can be easily modified for the analysis of a wide range of xenobiotics in various matrices including animal products rich in fat. Nevertheless, to attain high recoveries, the extraction, cleanup, and concentration steps have to be optimized according to the target compounds and matrix. Hence, QuEChERS is a promising and environmentally friendly methodology for the high-throughput routine analysis of xenobiotics in animal products. This review focuses on the application of QuEChERS to foods of animal origin and describes recent developments for the optimization of the analysis of veterinary drugs, pesticides, polycyclic aromatic hydrocarbons, and other compounds of concern.