A computationally supported designer benzodiazepine strategy for public toxicology laboratories.

Public laboratories must balance innovative and existing methods to keep up with designer drug trends. This article presents a strategy for handling designer benzodiazepines (DBZDs) in casework from screening to interpretation. The cross-reactivity of 22 DBZDs and metabolites was tested against the Immunalysis™ Benzodiazepine Direct Enzyme-Linked Immunosorbent Assay kit. The kit had high intra-analyte precision (coefficients of variation < 15%). Inter-analyte performance varied, triggering confirmation testing at concentrations ranging from 35 to 460 µg/L. The CCRFSL implemented a 40-analyte benzodiazepine and Z-drug confirmation method in 2019. Ten additional analytes were later validated for qualitative reporting, and the limits of detection (LODs) for 13 analytes were lowered by 60%. The method of standard addition was also optimized for as-needed quantitation. Equal and 1/x weighting factors correlated well with target concentrations (coefficients of determination (r2) > 0.98), but 1/x weighting provided the most consistently accurate concentrations. Six computational models were developed to predict DBZD binding affinity to the γ-aminobutyric acid-A receptor to assist in case interpretation (r2 > 0.7 for cross-validation and test set prediction). These models were used to predict the binding affinity of analytes in the confirmation method. Other public laboratories can use this same practical strategy to adapt to any designer drug class (e.g., benzodiazepines, opioids, cannabinoids, and stimulants).

Expansion of the EZSTATSG1 Microsoft Excel Tool for ANSI/ASB Standard 036 Method Validation by the Addition of Weighted Quadratic External Calibration Models Utilizing Five-, Six- or Seven-Point Curves.

The first generation of this Microsoft (MS) Excel (Redmond, WA, USA) tool for method validation, EZSTATSG1, was designed for methods utilizing only linear calibration curves requiring seven calibration levels, and quadratic calibration models were not supported. This significantly improved version, EZSTATSG2, includes all of the features of the original template such as weighted linear calibration models, bias and precision data, dilution integrity and ion suppression. New features in this version include flexible five-, six- or seven-point calibration curves; six weighted quadratic calibration models; standardized residuals by use of frequency plots overlaid with the normal distribution function along with five-number summary data and processed sample stability. The implementation of Visual Basic for Applications in Excel UserForms prevents accidental alteration of existing formulas and also ensures that pertinent cells are relocked every time a file is reopened. The quadratic models feature the 95% confidence intervals for checking the significance of the second-order term and are fully characterized by providing the equations for the axis of symmetry, directrix and coordinates for vertex and focus. Example data of α-hydroxymidazolam demonstrate that the quadratic calibration curves fit the data more adequately than the linear models for this method. This second-generation tool summarizes all of the validation parameters of a method for both linear and quadratic calibration models. Models with the lower average sum of relative errors and higher R2 values are color-coded green, indicating the likelihood of a better fitting model. Like the EZSTATSG1, the redesigned EZSTATSG2.xltm MS Excel self-actuating validation tool and a completed PDF example are available to the scientific community for download as supplementary data. Updates to the template can be found at www.EZSTATS4validation.com.

Assessment of Bioanalytical Method Validation Data Utilizing Heteroscedastic Seven-Point Linear Calibration Curves by EZSTATSG1 Customized Microsoft Excel Template.

Bioanalytical methods developed in accredited forensic toxicology laboratories need to be validated according to the ISO/IEC 17025 standards to demonstrate that a method is fit for the intended use. The evaluation of the validation data can be a time-consuming process without a streamlined procedure on a common platform or the aid of a specific software package. The objective of this work was to develop a Microsoft (MS) Excel (Redmond, WA, USA) template, which can rapidly generate all the required numerical and statistical validation results of a quantitative bioanalytical assay with minimal data entry and to provide documented traceability of the validation data directly to the instrument raw data. Evaluation of method validation data can be done easily by taking advantage of the power of statistical tools available within Excel. The three key features of the template were the development of six pertinent weighted linear calibration models, the variance in instrument response as a function of concentration and integrated one-way analysis-of-variance (ANOVA) tables. None of the ANOVA tables in this template need to be recreated whenever the source data changes, which is a major time savings when a method contains several dozen analytes. It takes ∼60 minutes per analyte to enter all the instrument raw data manually from the chromatograms. The final method validation results are summarized in a two-page validation summary report, whereas the associated data tables and graphs are presented in an additional 65 pages of digital information, which can be saved for electronic records using portable document format (PDF). This EZSTATSG1.xltm customized MS Excel method validation template and a completed PDF example are being provided as downloadable files in the Supplementary data link to offer an option to the scientific community for expediting the evaluation of validation data.

Development and Validation of an LC-MS-MS Method for the Detection of 40 Benzodiazepines and Three Z-Drugs in Blood and Urine by Solid-Phase Extraction.

An analytical method for the detection of 40 benzodiazepines, (±)-zopiclone, zaleplon and zolpidem in blood and urine by solid-phase extraction liquid chromatography-tandem mass spectrometry was developed and validated. Twenty-nine of 43 analytes were quantified in 0.5 mL whole blood for investigating postmortem, drug-facilitated sexual assault (DFSA) and driving under the influence of drugs cases (DUID). The four different dynamic ranges of the seven-point, linear, 1/x weighted calibration curves with lower limits of quantification of 2, 5, 10 and 20 µg/L across the analytes encompassed the majority of our casework encountered in postmortem, DFSA and DUID samples. Reference materials were available for all analytes except α-hydroxyflualprazolam, a hydroxylated metabolite of flualprazolam. The fragmentation of α-hydroxyflualprazolam was predicted from the fragmentation pattern of α-hydroxyalprazolam, and the appropriate transitions were added to the method to enable monitoring for this analyte. Urine samples were hydrolyzed at 55°C for 30 min with a genetically modified ß-glucuronidase enzyme, which resulted in >95% efficiency measured by oxazepam glucuronide. Extensive sample preparation included combining osmotic lysing and protein precipitation with methanol/acetonitrile mixture followed by freezing and centrifugation resulted in exceptionally high signal-to-noise ratios. Bias and between-and within-day imprecision for quality controls (QCs) were all within ±15%, except for clonazolam and etizolam that were within ±20%. All 29 of the 43 analytes tested for QC performance met quantitative reporting criteria within the dynamic ranges of the calibration curves, and 14 analytes, present only in the calibrator solution, were qualitatively reported. Twenty-five analytes met all quantitative reporting criteria including dilution integrity. The ability to analyze quantitative blood and qualitative urine samples in the same batch is one of the most useful elements of this procedure. This sensitive, specific and robust analytical method was routinely employed in the analysis of >300 samples in our laboratory over the last 6 months.

Unique Structural/Stereo-Isomer and Isobar Analysis of Novel Fentanyl Analogues in Postmortem and DUID Whole Blood by UHPLC-MS-MS.

The presented analytical method enabled the Toxicology Department at the Cuyahoga County Medical Examiner's Office to identify 26 and quantitatively report 24 compounds in 500 µL of whole blood, including fentanyl analogues (fentalogues) such as methoxyacetyl fentanyl (MeOAF) and cyclopropyl fentanyl (CPF). This second-generation method (FG2) was developed with the objective to improve the existing analysis (FG1) by decreasing sample size, lowering limits of detection (LOD) and lower limit of quantitation, minimizing ion suppression and resolving chromatographic interferences. Interferences may occur in the analysis of fentanyl, MeOAF, CPF, 3-methylfentanyl (3MF), butyryl fentanyl and isobutyryl fentanyl due to isobars and structural or geometric isomerism with another analogue or metabolite. The isomeric and isobaric fentalogues were grouped into three sets. The LOD established for Set 1 [MeOAF, para-methoxyacetyl fentanyl, para-fluoro acryl fentanyl (isobar), fentanyl carbamate], 2-furanyl fentanyl, Set 2 [CPF, (E)-crotonyl fentanyl] and carfentanil was 0.0125 ng/mL. The LOD established for N-methyl norfentanyl, norfentanyl, norcarfentanil, despropionyl fentanyl (4-ANPP), acetyl fentanyl, ß-hydroxy fentanyl, benzyl fentanyl, acryl fentanyl, alfentanil, fentanyl, para-fluoro fentanyl, Set 3 [(±)-trans-3MF, (±)-cis-3MF, isobutyryl and butyryl fentanyl], para-fluoroisobutyryl fentanyl, sufentanil, phenyl fentanyl and cyclopentenyl fentanyl was 0.0625 ng/mL. Seven-point linear calibration curves were established between 0.025 and 4.0 ng/mL for the 8 analytes with the lower LOD and 0.125 and 20 ng/mL for the 18 analytes with the higher LOD. 4-ANPP and cyclopentenyl fentanyl met qualitative reporting criteria only. The results for five postmortem and two driving under the influence of drugs authentic case samples are presented. To the authors' knowledge, FG2 is the first published method that achieved baseline resolution of the nine structural/stereo isomers and one isobar by ultra-high performance liquid chromatography-MS-MS and provided quantitative validation data for nine compounds. FG2 may be used as the new baseline for future isomers that need to be chromatographically separated.

An LC-MS-MS Method for the Analysis of Carfentanil, 3-Methylfentanyl, 2-Furanyl Fentanyl, Acetyl Fentanyl, Fentanyl and Norfentanyl in Postmortem and Impaired-Driving Cases.

In July of 2016, carfentanil (CF) emerged in Northeast Ohio resulting in over 25 deaths within a 30-day period. A total of 125 deaths have occurred in Summit County and Cuyahoga County has reported 40 deaths, relating to the presence of CF either alone, or in combinations with heroin and fentanyl. Prior to this surge in CF cases, positive fentanyl enzyme-linked immunosorbent assay (ELISA) screening results were increasing in number. Many were negative for fentanyl confirmation by gas chromatography-mass spectrometry. Fentanyl analogs such as CF, acetyl fentanyl (AF), 2-furanyl fentanyl (2-Fu-F) and 3-methylfentanyl (3-MF) may be present in these cases. Some fentanyl analogs like CF and 3-MF do not cross-react with the Immunalysis ELISA fentanyl assay. With the emergence of potent synthetic fentanyl analogs, questions arose as to how to interpret their very low concentrations or absence in the blood in relation to cause of death. Driving under the influence of drugs (DUID) blood specimens had also tested positive for CF by reference laboratories. A liquid chromatography-tandem mass spectrometry method was developed to identify and quantify fentanyl, norfentanyl (NF) and four analogs: AF, 2-Fu-F, 3-MF and CF. The method has been utilized to quantify these fentanyl analogs in blood and vitreous humor in authentic antemortem and postmortem cases. Calibration curves were established between 0.10-4.0 ng/mL (NF, AF, 3-MF, 2-Fu-F and CF) and 1.0-40 ng/mL for fentanyl. In total, 98 postmortem cases analyzed produced the following blood concentration ranges: CF (0.11-0.88 ng/mL), 3-MF (0.15-1.7 ng/mL), 2-Fu-F (0.15-0.30 ng/mL), AF (0.14-0.16 ng/mL), fentanyl (1.1-15 ng/mL) and NF (0.10-3.7 ng/mL). Only CF, fentanyl and NF were detected in a statistically significant subset DUID population of 26 cases producing concentration ranges between 0.11 and 0.47 ng/mL, 1.0 and 9.8 ng/mL, and 0.11 and 3.5 ng/mL, respectively.