Comparison of two acquisition modes in mass spectrometry for quantification of 12 antibiotics, including beta-lactams, linezolid, fluoroquinolones and clindamycin: Multiple reactions monitoring (MRM) and fullMS/dd-MS2.

The quantification of antibiotics, using mass spectrometry, for monitoring therapeutic drugs is a key benefit in infection management. After an easy work-up of plasma samples, analysis were performed using both two widely used acquisition modes: MRM for the triple quadrupole spectrometer and fullMS/ddMS2 for the HRMS to quantify twelve antibiotics. Comparison between the two acquisition modes were performed. Validation parameters and sample values were used as comparison criteria. The results indicated a good correlation between the two methods, with an advantage for HRMS concerning the matrix effect. Both methods were applied to routine therapeutic drug monitoring.

Development and Validation of a Non-Targeted Screening Method for Most Psychoactive, Analgesic, Anaesthetic, Anti-Diabetic, Anti-Coagulant and Anti-Hypertensive Drugs in Human Whole Blood and Plasma Using High-Resolution Mass Spectrometry.

(1) Background: In toxicological laboratories, various screening methods can be used to identify compounds involved in intoxication. High-resolution mass spectrometry has been increasingly used in this context for the last years, because of its sensitivity and reliability. Here, we present the development and validation of a screening method that uses liquid chromatography coupled with a high-resolution mass spectrometer. (2) Methods: This method required only 100 µL of whole blood or plasma sample. Pretreatment consisted of a rapid and simple deproteinisation with methanol/acetonitrile and zinc sulphate. This new assay was validated according to international guidelines. (3) Results: To perform the method validation, 53 compounds were selected. The selection criteria were as follows: various chemical structures and therapeutic families (>15), large m/z distribution, positive or negative ionisation mode, and various elution times. The assays showed high selectivity and specificity, with optimal process efficiency. The identification limits, determined using predefined criteria, were established at sub-therapeutic or therapeutic concentrations. Applicability was evaluated using spiked plasma controls and external quality controls. (4) Conclusions: The new method was then successfully applied to routine clinical and forensic samples.

Quantification of 15 Antibiotics Widely Used in the Critical Care Unit with a LC-MS/MS System: An Easy Method to Perform a Daily Therapeutic Drug Monitoring.

Potential under- or overdose of antibiotics may occur in intensive care units due to high variability in plasma concentrations. The risk is either treatment failure or toxicity. Thus, therapeutic drug monitoring of antibiotics may guide dosing adjustment, maximising antibacterial efficacy and minimising toxicity. The aim of this study was to develop and validate a method for the analysis of 15 antibiotics including beta-lactams, linezolid, fluoroquinolones, daptomycin, and clindamycin to have a complete panel in the management of infections. We proposed to develop a fast, sensitive, and quantitative method for the analysis of 15 antibiotics using ultra-performance liquid chromatography coupled with triple quadrupole mass spectrometer (UPLC-MS/MS) technology. this method required only 100 µL of plasma and consisted of a rapid liquid-liquid deproteinisation using methanol. Calibration curves ranged from 0.078 to 500 mg/L depending on the molecules, and were defined according to a therapeutic range. Inter- and intra-assay precisions values were less than 15%. This work described the development and the full validation of a precise, sensitive and accurate assay using UPLC-MS/MS technology. After validation, this new assay was successfully applied to routine therapeutic drug monitoring.

Quantification of methadone, buprenorphine, naloxone, opioids, and their derivates in whole blood by liquid chromatography-high-resolution mass spectrometry: Analysis of their involvement in fatal forensic cases.

Opioids represent a broad family of compounds that can be used in several indications: analgesics, antitussives, opioid substitution therapy (e.g. methadone, buprenorphine…). When these products are misused, they are often addictive. Thus, we aimed to develop an analytical method able to rapidly quantify several opiates and opioids (6-monoacetylmorphine, buprenorphine, codeine, dihydrocodeine, 2-ethyl-1,5-dimethyl-3,3-diphenylpyrrolidine, ethylmorphine, heroin, methadone, morphine, nalbuphine, naloxone, norbuprenorphine, norcodeine, norpropoxyphene, oxycodone and propoxyphene) in whole blood by ultra-high performance liquid chromatography combined with high resolution mass spectrometry (UHPLC-HRMS). The validated assay requires only 100 µL of the blood sample. The sample is prepared by a rapid liquid-liquid extraction using 5% zinc sulfate (W/V), methanol and acetonitrile. Calibration curves range from 0.98 to 1000 µg/L, except for buprenorphine (0.39-100 µg/L) and norbuprenorphine (0.20-100 µg/L). Inter- and intra-analytical accuracy was less than 15%. Therefore, we describe the development and full validation of an accurate, sensitive and precise assay using UHPLC-HRMS for the analysis of opioids in whole blood. After validation, this new assay is successfully applied on a routine laboratory application basis.

Simultaneous quantification of 8 nucleotides and adenosine in cells and their medium using UHPLC-HRMS.

Purinergic signalling is involved in physiological processes, particularly during ischemia-reperfusion injuries for which it has a protective effect. The purpose of this work was to develop a method for simultaneous quantification of eight nucleotides and adenosine in biological matrices by liquid chromatography coupled with high-resolution mass spectrometry. A method was developed that was sufficiently robust to quantify the targeted analytes in 20 min with good sensitivity. Analysis of extracellular media from cultured endothelial cells detected the release of nucleotides and adenosine during 2 h of hypoxia. The quantification of cylic adenosine monophosphate (cAMP) allowed to establish a dose-response curve after receptor stimulation. Therefore, our method allows us to study the involvement of nucleotides in various processes in both the intracellular and extracellular compartment.

Therapeutic drug monitoring of mitotane: Analytical assay and patient follow-up.

Adrenocortical carcinoma (ACC) is an aggressive malignancy of the adrenal gland. Mitotane (o,p'-DDD) is the most effective chemotherapy for ACC. According to the literature, mitotane plasma trough concentrations within 14-20 mg L-1 are correlated with a higher response rate with acceptable toxicity. Therapeutic drug monitoring (TDM) of mitotane is therefore recommended. The aim of this study was to propose a robust and simple method for mitotane quantification in plasma. The validation procedures were based on international guidelines. Sample preparation consisted of a single protein precipitation with methanol using 100 µL of plasma. The supernatant was submitted to liquid chromatography coupled with ultra-violet detection at 230 nm. Mitotane retention time was 7.1 min. The limit of detection was 0.1 mg L-1 and the limit of quantification was 0.78 mg L-1 . The assay demonstrated a linear range of 0.78-25 mg L-1 with correlation coefficients (r2 ) at 0.999. Inter- and intra-assay precision was <4.85%. Evaluation of accuracy showed a deviation <13.69% from target concentration at each quality control level. This method proved easy and rapid to perform mitotane TDM and required a small volume of sample. It was successfully applied to routine TDM in our laboratory.

Validation of a fast UPLC-MS/MS method for quantitative analysis of opioids, cocaine, amphetamines (and their derivatives) in human whole blood.

BACKGROUND: Conventional methods for analysis of drugs of abuse require multiple assays which can be both expensive and time-consuming. This work describes a novel, rapid, simple and sensitive method for the quantification of 14 illicit drugs and their metabolites in whole blood. Results/methodology: This method employed a rapid liquid-liquid sample extraction of whole blood followed by UPLC-MS/MS analysis. Calibration curves were validated for analysis of appropriate concentrations. Inter- and intra-assay variations were <14.8%. Deviation of accuracy was <14.9% from target concentration for each quality control level. CONCLUSION: This work described the development and the full validation of a precise, sensitive and accurate assay. After validation, this new assay was successfully applied to routine toxicological analysis.

Validation of a fast method for quantitative analysis of elvitegravir, raltegravir, maraviroc, etravirine, tenofovir, boceprevir and 10 other antiretroviral agents in human plasma samples with a new UPLC-MS/MS technology.

Therapeutic drug monitoring (TDM) of antiretrovirals requires accurate and precise analysis of plasma drug concentrations. This work describes a simple, fast and sensitive UPLC-MS/MS method for determination of the commonly used protease inhibitors such as amprenavir, atazanavir, darunavir, indinavir, lopinavir, ritonavir, saquinavir and tipranavir, tenofovir a nucleoside reverse transcriptase inhibitor (NRTI), the non-NRTI such as efavirenz, nevirapine, etravirine, the CCR5 antagonist maraviroc as well as the more recent antiretrovirals, the integrase inhibitors such as raltegravir, elvitegravir and the new direct acting anti-HCV boceprevir. Adapted deuterated internal standard was added to plasma aliquots (100µl) prior to protein precipitation with methanol and acetonitrile. This method employed ultra-performance liquid chromatography coupled to tandem mass spectrometry with electrospray ionization mode. All compounds eluted within 4.2-min run time. Calibration curves were validated, with correlation coefficients (r(2)) higher than 0.997, for analysis of therapeutic concentrations reported in the literature. Inter- and intra-assay variations were <15%. Evaluation of accuracy shows a deviation <15% from target concentration at each quality control level. No significant matrix effect was observed for any of the antiretroviral studied. This new validated method fulfills all criteria for TDM of 15 antiretrovirals and boceprevir drugs and was successfully applied in routine TDM of antiretrovirals.