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A rapid LC-MS/MS method for the determination of marbofloxacin in plasma and synovial fluid is presented in this study. The method uses a rapid sample preparation which only requires an ultrafiltration step with centrifugal filter devices. The optimized procedure allows a minimal need of sample (175 μL), particularly useful for synovial fluid samples which amount is rather limited; it is simple, rapid and easily applicable providing anyhow a satisfactory clean up, demonstrated by post-infusion experiments. On the other hand to maximize the speed of the analysis an ultrafast chromatographic separation has been obtained by selecting a column of 20 mm; the reduced run-time is suitable for processing numerous samples on a daily basis. Linearity was assessed in the range 5-2500 ng mL(-1); ofloxacin was used as internal standard. LOD and LOQ were respectively 1 and 5 ng/mL. The method was successfully applied to a set of samples generated during an experimental veterinary study., (Copyright © 2016 Elsevier B.V. All rights reserved.)

In this paper the development and validation of a method for the analysis of THC-COOH, THC, THC-OH, CBD and CBN in their total form in urine by LC-MS/MS is presented. Tandem hydrolysis, i.e. enzymatic and basic, has been found optimal for the simultaneous analysis of the selected analytes in urine: basic hydrolysis is more effective for the cleavage of THC-COOH glucuronide while enzymatic hydrolysis allows the cleavage of the conjugated cannabinoids possessing ether bonds (THC, THC-OH, CBD). The whole procedure requires a 2h enzymatic hydrolysis using only 90μL of urine by μ-SPE extraction technique with C18 tips. Clear advantages in terms of time and of enzyme reduction are obtained and the cost of the analysis can be dramatically reduced. Satisfactory recovery values and matrix effect are obtained, and the chromatographic run, performed with a fused-core column, allowed the complete analyte separation in only 3min (total run 5.8min) with a common HPLC system. Furthermore the whole procedure has been validated according to SWGTOX guidelines: LOQs are between 6 and 10ppb, quite lower than the requested cut-off for urine testing; intermediate reproducibility of the selected analytes is below 10% and accuracy is between 85% and 113%, except for CBD, included only for semi-quantitative determination., (Copyright © 2014 Elsevier B.V. All rights reserved.)

The method presented in this study allows the screening and quantification of 96 drugs, from different groups: opiates, amphetamines, hallucinogens, benzodiazepines, antihistamines, antidepressants, antipsychotics, barbiturates and other sedatives, muscle relaxants, etc. in hair. Drugs are extracted from 10mg of washed hair in 18h by a mixture of methanol:acetonitrile:ammonium formate (pH 5.3). Absolute recovery ranged from 70% to 106% for 75% of the analytes. The limits of detection in the low pg/mg range, may allow the detection of single dose drug exposure, with possible application in drug facilitated assaults (DFA); however, chronic use (compliance) can also be examined. The method has been fully validated for the drugs included in the study. The accuracy of the method was demonstrated by the analysis of certified authentic hair samples containing common drugs of abuse. The hair-method has broad potential as the measuring range is wide for the target analytes and new drugs can easily be added to the method due to the versatility of the extraction procedure and chromatographic system., (Copyright © 2013 Elsevier B.V. All rights reserved.)