LC-MS-sMRM method development and validation of different classes of pain panel drugs and analysis of clinical urine samples

Urine drug testing (UDT) is an important analytical/bio-analytical technique that has inevitably become an integral and vital part of a testing programme for diagnostic purposes. This manuscript presents a tailor-made LC-MS/MS quantitative assay method development and validation for a custom group of 33 pain panel drugs and their metabolites belonging to different classes (opiates, opioids, benzodiazepines, illicit, amphetamines, etc.) that are prescribed in pain management and depressant therapies. The LC-MS/MS method incorporates two experiments to enhance the sensitivity of the assay and has a run time of about 7 minutes with no prior purification of the samples required and a flow rate of 0.7 mL/min. The method also includes the second-stage metabolites for some drugs that belong to different classes but have first-stage similar metabolic pathways that will enable to correctly identify the right drug or to flag the drug that might be due to specimen tampering. Some real case examples and difficulties in peak picking were provided with some of the analytes in subject samples. Finally, the method was deliberated with some randomly selected de-identified clinical subject samples, and the data evaluated from "direct dilute and shoot analysis" and after "glucuronide hydrolysis" were compared. This method is now used to run routinely more than 100 clinical subject samples on a daily basis.

Supramolecular Sensors for Opiates and Their Metabolites

The present study highlights a sensing approach for opiates using acyclic cucurbituril (aCBs) sensors comprising four glycouril units terminated on both ends with naphthalene fluorophore walls. The connectivity between the glycourils and naphthalene rings largely defines the opening size of the cucurbituril cavity and its diameter. The large hydrophobic binding cavity is flexible and is able to adapt to guests of various size and topology. The recognition event between the aCBs and guests results in modification of the fluorescence of the terminal walls, a fluorescence response that can be used to sense the drugs of abuse morphine, heroin, and oxycodone as well as their metabolites. Molecular dynamics is employed to understand the nature of the binding interactions. A simple three sensor cross-reactive array enables the determination of drugs and their metabolites in water with high fidelity and low error. Quantitative experiments performed in urine using a new three-way calibration model allows for determination of drugs and their metabolites using one sensor from a single fluorescence reading.

A simple and robust LC-MS/MS method for measuring sirolimus and everolimus in whole blood

Therapeutic drug monitoring of immunosuppressants sirolimus and everolimus is mandatory and liquid chromatography tandem mass spectrometry (LC-MS/MS) is the preferred technology for the measurement. Due to the high hydrophobicity these analytes bind to reverse-phase columns tightly and need column heating to elute. Column heating not only requires extra instrument preparation but also causes permanent column damage if the heater is left on while elution pumps stop by the end of the run. The primary improvement in the current method was to elute the analytes at room temperature using special buffers. This new LC-MS/MS method has been validated for clinical use and offers improved simplicity and robustness by eliminating column heating yet with high sensitivity, precision and accuracy.

Drug confirmation by mass spectrometry: Identification criteria and complicating factors

Drug confirmation by mass spectrometry coupled with chromatography is essential to toxicology, doping control, pain management, and workplace drug testing. High confidence in this technology is due to its superior specificity and sensitivity. However, there are challenges associated with drug confirmation, and proper setup and validation of these assays are important in assuring high-quality results. In this article, assay parameters required for drug confirmation are summarized based on recent scientific publications, various established guidelines, and our own practical experience. Factors affecting the result quality and correct results interpretation are critically reviewed. Several emerging technologies and their potential applications are briefly explored.

The current role of on-line extraction approaches in clinical and forensic toxicology

In today's clinical and forensic toxicological laboratories, automation is of interest because of its ability to optimize processes, to reduce manual workload and handling errors and to minimize exposition to potentially infectious samples. Extraction is usually the most time-consuming step; therefore, automation of this step is reasonable. Currently, from the field of clinical and forensic toxicology, methods using the following on-line extraction techniques have been published: on-line solid-phase extraction, turbulent flow chromatography, solid-phase microextraction, microextraction by packed sorbent, single-drop microextraction and on-line desorption of dried blood spots. Most of these published methods are either single-analyte or multicomponent procedures; methods intended for systematic toxicological analysis are relatively scarce. However, the use of on-line extraction will certainly increase in the near future.

Laboratory medicine and medical oncology: the tale of two Cinderellas

Cancer represents a leading cause of death in the developed countries. The past 50 years have witnessed major progress in both laboratory medicine and clinical oncology that has translated into improved prognosis of cancer patients. From the humble beginnings as unrelated specialties, major advances in the understanding of molecular bases of cancer progression led to increased interactions between laboratory medicine and clinical (mostly medical) oncology. Laboratory medicine is now an integral part of the management of cancer patients. The many aspects of the role of laboratory medicine in clinical oncology include the determination of biomarkers that are used in establishing the diagnosis, predicting response to therapy or prognosis, study of the host response to tumor growth, detection of treatment toxicity and determining the concentrations of anticancer drugs.