Since the wide adoption of liquid chromatography/tandem mass spectrometry (LC/MS/MS), the ion suppression/enhancement phenomenon is the latest barrier to high-throughput analysis. This consequence of a nonoptimized analytical method can lead to adverse effects during quantitation (i.e. poor accuracy and precision). Previous papers have reported that ion suppression is a direct result of endogenous material present in biological samples. However, in the case of a solid-phase liquid chromatography/tandem mass spectrometry (SPE/LC/MS/MS) system, the measured result is the combination of several operating conditions and parameters. Little has been done to effectively monitor and/or choose optimized conditions for the complete sequence of extraction, clean up, separation and analysis. This paper describes a simple setup for quantification of ion suppression/enhancement. Several mobile phase additives, ion-pairing agents and SPE extracts were measured and compared against a standard reference. The results demonstrated that a clean up of plasma extracts based on ion exchange leads to minimal ion suppression/enhancement for the compounds that were investigated.
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http://dx.doi.org/10.1002/rcm.1276 | DOI Listing |
J Chromatogr B Analyt Technol Biomed Life Sci
October 2024
Department of Forensic Medicine and Toxicology, Faculty of Medicine, School of Health Sciences, University of Ioannina, University Campus, Ioannina 45500, Greece; University Hospital of Ioannina, Ioannina 45110, Greece. Electronic address:
Liquid chromatography coupled with mass spectrometry (LC-MS) has been tremendously used for screening purposes in forensic toxicology, because of their great adaptability and reasonable time/resource consumption. Herein, a fully validated method based on liquid-liquid extraction (LLE) in human whole blood, by a multiple reaction monitoring (MRM) analysis through LC-MS/MS, is described. The proposed method simultaneously detects 100 analytes (plus three deuterated internal standard compounds) belonging to many different classes, including drugs of abuse, prescription and over-the-counter drugs commonly involved in poisoning and medical malpractice cases in our territory, as well as certain new psychoactive substances (NPS) and toxic substances potentially associated with adverse effects.
View Article and Find Full Text PDFJ Anal Toxicol
October 2024
State of Maryland Office of the Chief Medical Examiner, 900 West Baltimore St., Baltimore, MD 21223, United States.
Liquid chromatography-triple quadrupole mass spectrometry (LC-MS-MS) assays are frequently utilized for screening and confirmatory purposes in the forensic toxicology laboratory. While these techniques are excellent for the targeted identification and quantitation of a wide variety of drug classes, validation and determining fit-for-purpose is a significant requirement for each method. In the USA, the American National Standards Institute and Academy Standards Board first edition of Standard 036 currently serves as a primary resource in forensic toxicology method validation and mandates that laboratories evaluate critical performance characteristics to help ensure the production of forensically defensible results.
View Article and Find Full Text PDFJ Chromatogr B Analyt Technol Biomed Life Sci
March 2024
Department of Clinical Medicine, Aarhus University, Denmark; Aarhus Denmark Microdialysis Research Group (ADMIRE), Orthopaedic Research Laboratory, Aarhus University Hospital, Denmark; Department of Orthopaedic Surgery, Aarhus University Hospital, Denmark.
Cisplatin is a potent cytotoxic agent used in the treatment of various malignancies and exerts its antitumor effect through malignant cell DNA damage and apoptosis induction. Evaluation of systemic delivery of cisplatin is important in optimization of cisplatin treatment. However, accurate quantification of systemic cisplatin is challenging due to its various forms in circulation.
View Article and Find Full Text PDFJ Sep Sci
December 2023
Department of Chemistry and Biochemistry, The University of Toledo, Toledo, Ohio, USA.
Matrix effects can significantly impede the accuracy, sensitivity, and reliability of separation techniques presenting a formidable challenge to the analytical process. It is crucial to address matrix effects to achieve accurate and precise measurements in complex matrices. The multifaceted nature of matrix effects which can be influenced by factors such as target analyte, sample preparation protocol, composition, and choice of instrument necessitates a pragmatic approach when analyzing complex matrices.
View Article and Find Full Text PDFChem Res Toxicol
September 2023
PinPoint Testing, LLC, Little Rock, Arkansas 72202, United States.
Forensic laboratories need quick and simple technology to improve turnaround times, while delivering reliable results. The goal of this study is first to create a simplified workflow to meet new Academy Standards Board requirements for urine testing in drug-facilitated crime investigations and, second, to create "ready-to-go", "hands-free" testing technology to further streamline analytical procedures. A first of its kind, the ToxBox forensic test kit is used to validate a single analytical procedure for opioids, benzodiazepines, cannabinoids, antidepressants, and several other drug classes.
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