Trace analysis of 20 antihistamines in milk by ultrahigh performance liquid chromatography coupled with high field quadrupole orbitrap high resolution mass spectrometry followed dispersive micro solid phase extraction.

Ultrahigh-performance liquid chromatography coupled with high-field quadrupole Orbitrap high resolution mass spectrometry was used for the separation and determination of 20 antihistamines, and a dispersive micro solid-phase extraction procedure using high-performance absorbing material was developed as a sample preparation strategy for extracting 20 antihistamines from milk. Instrument conditions and key parameters influencing extraction efficiency were investigated to obtain an optimized method. The limit of detection for 20 antihistamines in milk using this method is 0.05 µg/L to 1.0 µg/L. Recoveries are between 80.7 % and 108.3 %, and the relative standard deviation is less than 15 %. It is suitable for confirmatory monitoring and quantitative analysis of 20 antihistamines in milk. The results show that antihistamines in milk may be noteworthy issues for human health and environmental pollution.

Multi-residue determination of five quinoxalines and three their metabolites in poultry feathers and its application for depletions of olaquindox and quincetone in chickens.

A method for the simultaneous determination of eight quinoxalines and their metabolites in poultry feathers was developed in this study using ultra-performance liquid chromatography combine with quadrupole linear ion trap electrostatic field orbit trap high resolution mass spectrometer. Specificity, matrix effect, linearity, trueness, repeatability, reproducibility, and stability using the Commission of the European Communities, Regulation (EU) 2021/808. The correlation coefficients were all greater than 0.99. The average recoveries of the eight compounds ranged from 76.1% to 112.8%, with coefficient of variation of less than 15%. The limits of detection and quantification of the method were 0.04-0.1 µg/kg and 0.12-0.3 µg/kg, respectively. The method has been successfully applied to depletions of olaquindox and quincetone in feathers of laying hens. Methylquinoxaline-2-carboxylic acid and quincetone are the main metabolites in olaquindox and quincetone in feather, respectively.

Simultaneous determination of 10 first-generation histamine h1 receptor blockers in feeds by ultra-high-performance liquid chromatography triple quadrupole ion trap hybrid mass spectrometer.

A method for simultaneous determination of 10 first-generation histamine H1 receptor blockers in feeds by ultra-high-performance liquid chromatography triple quadrupole mass spectrometry combined with solid phase extraction. Instrument conditions, extraction solvents, and purification methods have been optimized. Under the optimum conditions, these analytes were separated effectively at 6 min. These feeds have been extracted by acid acetonitrile and purified by mixed cation exchange solid-phase extraction. The performance of this method meets the requirements of veterinary residue detection in feeds in China. It is appropriate for the confirmatory monitoring and quantitative analysis of 105 feed samples, five kinds of histamine H1 receptor blockers have been detected in 10 samples.

Simultaneous determination of eight carbapenems in milk by modified QuEChERS and ultra high performance liquid chromatography coupled with high-field quadrupole-orbitrap high-resolution mass spectrometry.

A simple and accurate method of ultra high performance liquid chromatography (UHPLC) coupled with quadrupole-high field Orbitrap high-resolution mass spectrometry (QE HF HRMS) has been developed for analyzing 8 trace-level (µg/L) carbapenems in milk. Mass spectrometry conditions, chromatographic conditions, extraction solvent and QuEChERS procedures were optimized for determination of 8 carbapenems in milk. Samples were extracted and purified by modified QuEChERS procedure. Good separation for 8 carbapenems s was achieved with a PFP column at 8 min. Method validation results showed the linear ranges are 1-100 µg/L to 10-1,000 µg/L, the correlation coefficients are more than 0.995, and the recoveries of spiked samples are 79.3%-104% with a relative standard deviation less than 15%. This method successfully applied to monitor residue of carbapenems in real milk, four kinds of carbapenems have been detected in 8 sample of 79 collected milks with concentration ranged between 15 µg/L∼3,325 µg/L.

Residue accumulation, distribution, and withdrawal period of sulfamethazine and N-acetylsulfamethazine in poultry waste from broilers.

Sulfamethazine is one of the most frequently used sulfonamides in the poultry farming industry. However, the residue accumulation, distribution, and depletion of sulfamethazine (SMZ) and its metabolite, N4-acetylsulfamethazine (NAS), in poultry waste (manure and feathers) have yet to be evaluated. In our study, the residue levels of SMZ and NAS in manure and feathers are determined by liquid chromatography tandem mass spectrometry. Furthermore, the distribution, depletion, and withdrawal period of SMZ and NAS in manure and feathers are investigated under field conditions. Results show that high concentrations (0.7-43.3 mg/kg for SMZ, and 0.22-22.4 mg/kg for NAS) of SMZ and NAS residues remain in manure and feathers even when SMZ has been used. The withdrawal periods of SMZ and NAS in feathers are 97.0 d and 28.0 d, respectively. In manure, the withdrawal period is 18.2 d and 8.0 d, respectively. Poultry waste is a possible major reentry way of SMZ into the food chain and the environment.

Trace analysis of progesterone and 21 progestins in milk by ultra-performance liquid chromatography coupled with high-field quadrupole-orbitrap high-resolution mass spectrometry.

A method for rapid screening and quantification of progesterone and progestins in milks by ultrahigh-performance liquid chromatography coupled with quadrupole-high field Orbitrap high-resolution mass spectrometry (UHPLC QE HF HRMS) was established. Milks samples were extracted by acetonitrile + hexane (80 + 20), purified by prime HLB SPE and analyzed by UHPLC QE HF HRMS. The detection limit of progesterone and 21 progestins in milk is between 0.05 µg/kg -0.3 µg /kg, the correlation coefficient of progesterone and progestins in the corresponding concentration range is more than 0.99, recoveries for milk samples are between 80.7% and 108.3% with the relative deviation is less than 15%.The method fulfils the requirements of veterinary drug residue detection validation of EU and China, and successfully applied to detecting the µg/kg level of progesterone and monitoring residual of progestins in real milk.

Multiresidue determination of 19 anabolic steroids in animal oil using enhanced matrix removal lipid cleanup and ultrahigh performance liquid chromatography-tandem mass spectrometry.

A method for sensitive analysis of 19 anabolic steroids (AS) in animal oil using enhanced matrix removal lipid (EMR-Lipid) cleanup and ultrahigh performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was developed. Oil samples were extracted with 20 mL of acetonitrile aqueous solution and purified using EMR-Lipid cartridges. The eluent was evaporated to dryness under nitrogen and analyzed by UHPLC-MS/MS using 0.1% formic acid-acetonitrile and 0.1% formic acid-water solutions as the mobile phase via gradient elution. The method effectively removed unwanted matrix co-extractives better than other extraction cleanup techniques while still delivering acceptable recovery results for most of the AS. The established quantification method showed AS recovery in the range of 72.9-110.7% with good precision (relative standard deviation < 15%).

Analysis of Choline, Carnitine, Acetylcarnitine and Acetylcholine in Animal Feeds, Blood and Urine Using Ion Chromatography Coupled with Tandem Mass Spectrometry.

A simple and sensitive method was proposed for choline, carnitine, acetylcarnitine (ACa) and acetylcholine (ACh) separation in feed, blood and urine of animals by using ion chromatography (IC) and detection by tandem mass spectrometry (MS/MS). Analytes were extracted using a mixture of acetonitrile and water, purified by C18 solid-phase extraction columns, separated via IC with an IonPac SCS-1 column and detected by an MS/MS detector by using isotopic internal standards for quantification. The effects of different chromatographic parameters on the separation were also investigated. Under optimal conditions, the recovery was >90%, with the relative standard deviations of <15%. The proposed method was highly reliable for the simultaneous determination of choline, carnitine, ACa and ACh in feed, blood and urine.

Evaluation of ß-agonists in blood meal: Validation of determination method and potential pathway for reentry into the environment.

ß-agonists, which have been illegally used in animal production in some countries, can induce bioaccumulation when blood is converted by rendering into blood meal. Unfortunately, available data on this topic are scarce, which result in lack of risk assessment. Therefore, in this research, a method for simultaneous determination of 22 ß-agonists in blood meal by liquid chromatography coupled with tandem mass spectrometry using isotope dilution was developed. The recoveries of the developed method ranged from 68.6% to 118.8% with RSD at below 20%. the limit of detection (LOD) is blew 1 µg/kg. The change in agonist form added and incurred blood into blood meal and long stability of ß-agonist in blood meal were studied. Then, we analyzed blood meal for 22 agonists using this method. The results suggest blood meal is a possible pathway for agonist reentry into animals. Potential risks of agonist residues in blood meal were examined. This study is the first to explore source of ß-agonist residues in blood meal, change in processing produce and stability in stored stage.

Simultaneous determination of antibiotics and amantadines in animal-derived feedstuffs by ultraperformance liquid chromatographic-tandem mass spectrometry.

In this study, a method for simultaneous determination of 40 antibiotics from 6 different drug families (7 quinolones, 5 penicillins, 8 macrolides, 2 lincosamides, 4 tetracyclines, and 13 sulfonamides) and 3 amantadines in animal-derived feedstuffs (ADF) through ultraperformance liquid chromatography-tandem mass spectrometry using a new lipid-removing solid-phase extraction column PRiME HLB was developed. The sample was extracted with 20 mL extraction solution and then purified and concentrated with PRiME HLB. The eluent was evaporated to dryness under nitrogen and analyzed with LC-MS/MS using acetonitrile and 0.1% formic acid as the mobile phase via gradient elution. Under the optimum conditions, recoveries were 65.8% to 104.4% with a relative standard deviation of <15% at spiked levels of 5.0 µg/kg to 100 µg/kg. The limits of detection ranged from 0.5 µg/kg to 5 µg/kg. 15 of the 43 drugs were found in ADF. Sulfonamides, fluoroquinolones, macrolides, tetracyclines, and amantadines were detected, with the highest levels reaching 325 µg/kg.

Accumulation and Determination of Phenylethanolamine A Residue in Hair of Swine and Sheep.

The present study proposed the use of liquid chromatography-tandem mass spectrometry to detect the novel ß-agonist phenylethanolamine A (PEA) in incurred hair samples of swine and sheep and to assess its accumulation for residue monitoring. The method showed good percent recoveries ranging from 93.2% to 102% and good coefficient of variation at <15%. The experiment was conducted in swine (24 treated and 4 controls) and sheep (3 treated and 1 control). PEA concentration was determined in hair during the treatment. High residue concentrations were present in hair as early as Day 24 (14.8 ± 3.6 and 25.8 ± 7.6 ng/g) and Day 21 (23.4 ± 6.6 ng/g) for swine and sheep; these residues persisted until withdrawal on Days 14 and 21. Results showed high PEA accumulation in hair, thereby indicating the use of hair as a matrix in the control of PEA abuse in farm animals.

Validation of a confirmatory method of salbutamol in sheep hair by UPLC-MS/MS and its application to pharmacokinetic study.

A new method for determining salbutamol in hair of sheep by ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) was established. Samples were extracted with 0.1M of HCl solution. The mixture was heated to 60 °C in a water bath and kept at this temperature for 4h. The extracts were purified through SPE method and then dried with nitrogen. Residues were redissolved in mobile phase. The target compound was determined by UPLC-MS/MS with BEH-C18 column. The usefulness and feasibility of different treatment procedures of hair containing salbutamol were evaluated. The range of linearity was 1-100 ng/g. The LOD was 0.3 ng/g, and the LOQ was 1 ng/g. Recoveries were 89-106%, and coefficients of variation were 3.2-13.9%. Pharmacokinetics of salbutamol was studied in healthy sheep after oral administration of 150 µg/kg body weight salbutamol for 21 consecutive days. Salbutamol residues in hair were still detected after 21 days of administration.