Strategic Decision-Making by a Forensic Toxicology Laboratory in Response to an Emerging NPS: Detection, Quantitation, and Interpretation of Carfentanil in Death Investigations in Ontario, Canada, July 2017 to June 2018

2021 ◽  
Author(s):  
Patricia Solbeck ◽  
Karen L Woodall ◽  
Teri L Martin
Keyword(s):  
Quantitative Methods ◽  
Limit Of Detection ◽  
Safety Concern ◽  
Forensic Toxicology ◽  
Strategic Decision ◽  
Forensic Sciences ◽  
Screening Methods ◽  
Limited Information ◽  
Postmortem Blood ◽  
Added Benefit

Abstract The proliferation of novel psychoactive substances (NPS) and the current opioid epidemic creates challenges for a toxicology laboratory. Methods capable of detecting and quantitating emerging compounds must be established despite limited information on toxicologically relevant concentrations. This paper will (1) describe how a publicly funded forensic laboratory reacted to the emergence of carfentanil as a public safety concern, and (2) contribute to the existing forensic literature by presenting a series of deaths involving carfentanil between July 2017 and June 2018. The Centre of Forensic Sciences is the primary provider of forensic toxicology testing in medicolegal death investigations in the province of Ontario. When carfentanil was first identified in the illicit drug supply, routine screening methods used by this laboratory were not sufficiently sensitive to detect the drug at concentrations expected in blood samples. Previously validated, multi-target LC–MS-MS quantitative methods already in use by the laboratory did show improved detectability for carfentanil. Thus, an existing LC–MS-MS method was adapted to include carfentanil; achieving improved sensitivity while also providing quantitation in suspected drug-related deaths. This approach had the added benefit that the LC–MS-MS method selected for modification was performed in all death investigations requiring toxicology analysis in Ontario, thereby providing an opportunity for surveillance. Using this method, 4953 cases were analyzed with carfentanil detected at a concentration greater than the limit of detection (0.05 ng/mL) in 160 decedents. Postmortem blood carfentanil concentrations ranged from less than 0.1 ng/mL to 9.2 ng/mL. Of the 160 carfentanil-positive cases, 156 were classified as either mixed drug toxicity or carfentanil overdose. The approach described enabled this laboratory to efficiently implement a quantitative test for carfentanil in all death investigations providing a useful template for modifying existing methods when a new psychoactive substance becomes available in the population.

Comparing ELISA and LC-MS/MS: A Simple, Targeted Postmortem Blood Screen

2021 ◽  
Author(s):  
Dina M Swanson ◽  
Julia M Pearson ◽  
Theresa Evans-Nguyen
Keyword(s):  
Mass Spectrometry ◽  
Sample Preparation ◽  
Limit Of Detection ◽  
Screening Method ◽  
Chemical Properties ◽  
Forensic Toxicology ◽  
Enzyme Linked Immunosorbent Assay ◽  
Minimal Sample ◽  
Elisa Testing ◽  
Postmortem Blood

Abstract A comprehensive screening method that is specific, accurate, and customizable is necessary in any forensic toxicology laboratory. Most laboratories utilize some form of immunoassay testing as it is reliable and sensitive with minimal sample preparation and is relatively inexpensive to simultaneously screen for multiple classes of drugs with different chemical properties. However, accessibility to more specific technology and instrumentation such as mass spectrometry has increased and therefore using immunoassay as the screening method of choice may be revisited. A screening method for 42 drugs in postmortem blood was developed and validated following the Organization of Scientific Area Committees for Forensic Science (OSAC) guidelines for toxicology method validation. The method was developed using minimal sample preparation of postmortem blood consisting only of a protein precipitation. Only two internal standards were used which greatly reduces the cost of implementing this method. Limit of detection (LOD), interference studies, processed sample stability and ion suppression/enhancement were examined. Additionally, over 100 case samples were analyzed by both the current enzyme linked immunosorbent assay (ELISA) testing procedure and the proposed liquid chromatography tandem mass spectrometry (LC-MS/MS) screening method. The comparison determined that the LC/MS-MS method performed as well as or better than the ELISA in nearly all cases. The ability to add additional target drugs increases the laboratory’s scope of analysis as well. This method is ideal for forensic laboratories wishing to improve screening while working within budget constraints.

scholarly journals A Molecularly Imprinted Polymer for Selective Extraction of Phenolic Acids from Human Urine

2021 ◽  
Vol 11 (4) ◽  
pp. 1577
Author(s):  
Marco Mora-Granados ◽  
David González-Gómez ◽  
Jin Su Jeong ◽  
Alejandrina Gallego-Picó
Keyword(s):  
Phenolic Acids ◽  
Molecularly Imprinted Polymer ◽  
Human Urine ◽  
Limit Of Detection ◽  
Ph Dependence ◽  
Selective Extraction ◽  
Screening Methods ◽  
Specific Method ◽  
Imprinted Polymer ◽  
Molecularly Imprinted

Studies for monitoring the bioavailability of dietary flavonoid compounds generate great interest. Among them, low-molecular-weight phenolic acids, secondary metabolites present in colonic catabolism and urinary excretion, have been proposed as biomarkers of polyphenol intake. Using 4-hydroxyphenylacetic acid as a template, a molecularly imprinted polymer (MIP) was synthesized for selective extraction of these hydroxylated metabolites from human urine samples and posterior analysis in an HPLC-DAD-MS system. Polymers were characterized by Scanning electron microscopy (SEM), Attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), Brunauer-Emmett-Teller (BET) method, and binding experiments. MIP presents specific recognition ability for template and analogues molecules. This capacity of recognition and the pH dependence of the binding strength was also studied. The method was validated over a concentration range of 0.25–40 mg/L, r2 > 0.995. In the optimized conditions, the recovery value was 94% with RSD 1.2%. The Limit of Detection (LOD) and Limit of Quantification (LOQ) were 1.22 and 3.69 mg/L, respectively. In our knowledge, it is the first time that this methodology is applied to analyze urinary catabolites of the polyphenol compound and to provide a specific method and simple analysis alternative. The selective extraction of these metabolites improves the application and results obtained by other less sensitive analysis methods than the validation method. It also facilitates the development of new screening methods.

scholarly journals Spectroscopy as a useful tool for the identification of changes with time in post-mortem vitreous humor for forensic toxicology purposes

2021 ◽  
Author(s):  
Anna Wójtowicz ◽  
Agata Mitura ◽  
Renata Wietecha-Posłuszny ◽  
Rafał Kurczab ◽  
Marcin Zawadzki
Keyword(s):  
Ir Spectra ◽  
Forensic Toxicology ◽  
Principal Component ◽  
Hierarchical Cluster ◽  
Vitreous Humor ◽  
Attenuated Total Reflection ◽  
Glass Slides ◽  
Added Benefit ◽  
Ft Ir ◽  
Non Destructive

AbstractVitreous humor (VH) is an alternative biological matrix with a great advantage of longer availability for analysis due to the lack of many enzymes. The use of VH in forensic toxicology may have an added benefit, however, this application requires rapid, simple, non-destructive, and relatively portable analytical analysis methods. These requirements may be met by Fourier transform infrared spectroscopy technique (FT-IR) equipped with attenuated total reflection accessory (ATR). FT-IR spectra of vitreous humor samples, deposited on glass slides, were collected and subsequent chemometric data analysis by means of Hierarchical Cluster Analysis and Principal Component Analysis was conducted. Differences between animal and human VH samples and human VH samples stored for diverse periods of time were detected. A kinetic study of changes in the VH composition up to 2 weeks showed the distinction of FT-IR spectra collected on the 1st and 14th day of storage. In addition, data obtained for the most recent human vitreous humor samples—collected 3 and 2 years before the study, presented successful discrimination of all time points studied. The method introduced was unable to detect mephedrone addition to VH in the concentration of 10 µg/cm3. Graphic abstract

Detection and residence time of bisphosphonates in bone of horses

2021 ◽  
Vol 34 (1) ◽  
pp. 23-27
Author(s):  
Heather K. Knych ◽  
Jennifer Janes ◽  
Laura Kennedy ◽  
Daniel S. McKemie ◽  
Rick M. Arthur ◽  
...  
Keyword(s):  
Synovial Fluid ◽  
Residence Time ◽  
Bone Fractures ◽  
Limited Information ◽  
Long Term Effects ◽  
Normal Bone ◽  
Postmortem Blood ◽  
Affect Bone Healing ◽  
Postmortem Sample

Bisphosphonates are potent anti-resorptive agents that have the potential to adversely affect bone healing in equine athletes, and normal bone adaption in young racehorses. A concern exists that bisphosphonate inhibition of normal bone metabolism could lead to increased bone fractures during high-intensity exercise. We found only a single report describing concentrations of tiludronate in the bone of horses, and no studies describing clodronate. Knowledge of the residence time in bone could allow for a better understanding of the long-term effects of these compounds. Our objectives were to develop a method for detection of bisphosphonates in bone and add to the limited information available regarding the disposition of these drugs in the bone of horses. Two horses received clodronate and 2 tiludronate disodium. Postmortem collection of bones and teeth occurred either 4 or 30 d post drug administration. Additionally, postmortem blood, synovial fluid, aqueous humor, and bone samples from racehorses with various histories of bisphosphonate administration were collected, and concentrations determined using the developed LC-MS/MS method. Bisphosphonates were detected in bones and teeth tested at 4 and 30 d. In a postmortem sample, clodronate was detected in bone from a horse with reported administration 18 mo prior; clodronate was not detected in other sample types collected from this horse. Bisphosphonates reside in bone for extended periods of time, which could lead to potential long-term effects, increasing the potential for bone fractures in young and/or athletic horses.

Data Mining and the World of Commerce

2011 ◽  
pp. 1-17
Author(s):  
Stephan Kudyba
Keyword(s):  
Data Mining ◽  
Quantitative Methods ◽  
Operational Efficiency ◽  
General Information ◽  
Strategic Decision ◽  
Complex Nature ◽  
Multivariate Modeling ◽  
The World ◽  
Expert Input ◽  
Industry Sectors

Despite the research written, the software developed and the business applications that can be enhanced by it, the terms data mining and multivariate modeling continue to stoke uncertainty, complexity and sometimes fear in business managers and strategic decision-makers across industry sectors. Why is this? There are a number of reasons to cite, but probably the most common involves the complex nature of the methodologies incorporated in this analytic technique. The complexity we refer to involves the use of mathematical equations, sophisticated algorithms and advanced search and query techniques, not to mention statistical applications that are utilized in analyzing data. If that is not enough to throw management back on their heels, how about data acquisition, normalization, and model optimization, which are often involved in the process? Let’s add one more attribute to the list, and that is the ability to not only understand these complex methods, but more importantly, to understand when and where they can be used to enhance operational efficiency. Now is there any wonder why data mining continues to be this mysterious phenomenon in the world of commerce? No doubt; however, to dispel some of the uncertainties regarding this issue, the following book will provide the reader with expert input on how these quantitative methods are being used in prominent organizations in a variety of industry sectors to help enhance productivity, efficiency and to some extent, profitability. Before we get into the details of the applied material, the following chapter will provide some general information on what data mining and multivariate modeling is, where it came from, and how it can be used in a corporate setting to enhance operational efficiency.

scholarly journals Electrochemical detection of different p53 conformations by using nanostructured surfaces

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Sarah Tonello ◽  
Francesca Stradolini ◽  
Giulia Abate ◽  
Daniela Uberti ◽  
Mauro Serpelloni ◽  
...  
Keyword(s):  
Quantitative Analysis ◽  
Limit Of Detection ◽  
Direct Electrochemistry ◽  
Protein Quantification ◽  
Label Free ◽  
Limited Information ◽  
Clinical Practices ◽  
Nanostructured Surfaces ◽  
Integrated Devices ◽  
Biochemical Assays

AbstractProtein electrochemistry represents a powerful technique for investigating the function and structure of proteins. Currently available biochemical assays provide limited information related to the conformational state of proteins and high costs. This work provides novel insights into the electrochemical investigation of the metalloprotein p53 and its redox products using label-free direct electrochemistry and label-based antibody-specific approaches. First, the redox activities of different p53 redox products were qualitatively investigated on carbon-based electrodes. Then, focusing on the open p53 isoform (denatured p53), a quantitative analysis was performed, comparing the performances of different bulk and nanostructured materials (carbon and platinum). Overall, four different p53 products could be successfully discriminated, from wild type to denatured. Label-free analysis suggested a single electron exchange with electron transfer rate constants on the order of 1 s−1. Label-based analysis showed decreasing affinity of pAb240 towards denatured, oxidized and nitrated p53. Furthermore, platinum nanostructured electrodes showed the highest enhancement of the limit of detection in the quantitative analysis (100 ng/ml). Overall, the obtained results represent a first step towards the implementation of highly requested complex integrated devices for clinical practices, with the aim to go beyond simple protein quantification.

Evaluation of the Methods Used for Carboxyhemoglobin Analysis in Postmortem Blood

2005 ◽  
Vol 24 (4) ◽  
pp. 275-281 ◽  
Author(s):  
Vassiliki A. Boumba ◽  
Theodore Vougiouklakis
Keyword(s):  
Carbon Monoxide ◽  
Forensic Toxicology ◽  
Blood Samples ◽  
Spectrophotometric Methods ◽  
Detection Systems ◽  
Acceptable Accuracy ◽  
Postmortem Blood ◽  
Criteria For Evaluation ◽  
Automated Instruments

Numerous methods have been described in the literature for the determination of carboxyhemoglobin (COHb) in whole blood. The most popular and widely used have been (1) the spectrophotometric methods, which could be performed either by using a conventional spectrophotometer or by using specialized automated instruments known as CO-oximeters; (2) the gas chromatographic methods, with variable detection systems, which have been considered as the reference methods for every carbon monoxide analysis. The authors have critically reviewed previously reported comparative studies on these methods, considering statistical and analytical matters, in order to propose the best method for the determination of COHb in postmortem blood, that could be utilized in forensic toxicology laboratories where such analyses are limited in number (less than 20 per year). Criteria for evaluation have been accuracy, reliability, simplicity, time, and cost. The authors’ concluding statement has been that the manual spectrophotometric method could be the method of choice for COHb determination in postmortem blood samples. It is simple, rapid, and reliable and fulfills the forensically acceptable accuracy. It is performed by the use of a conventional spectrophotometer, which is considered a basic instrument in every analytical laboratory.

Identification of Suvorexant in Blood Using LC–MS-MS: Important Considerations for Matrix Effects and Quantitative Interferences in Targeted Assays

2019 ◽  
Vol 44 (3) ◽  
pp. 245-255 ◽  
Author(s):  
Britni Skillman ◽  
Sarah Kerrigan
Keyword(s):  
Matrix Effects ◽  
Limit Of Detection ◽  
Chemical Properties ◽  
Internal Standard ◽  
Forensic Toxicology ◽  
Calibration Model ◽  
Physico Chemical ◽  
Limit Of Quantitation ◽  
Liquid Chromatography Tandem Mass ◽  
Electrospray Interface

Abstract Suvorexant (Belsomra®) is a novel dual orexin receptor antagonist used for the treatment of insomnia. The prevalence of suvorexant in forensic samples is relatively unknown, which demonstrates the need for robust analytical assays for the detection of this sedative hypnotic in forensic toxicology laboratories. In this study, suvorexant was isolated from whole blood using a simple acidic/neutral liquid–liquid extraction followed by analysis by liquid chromatography tandem mass spectrometry (LC–MS/MS). Matrix effects were evaluated qualitatively and quantitatively using various extraction solvents, proprietary lipid clean-up devices and source conditions. The method was validated in terms of limit of detection, limit of quantitation, precision, bias, calibration model, carryover, matrix effects and drug interferences. Electrospray is a competitive ionization process whereby compounds in the droplet compete for a limited number of charged sites at the surface. As such, it is capacity-limited, and LC–MS-based techniques must be carefully evaluated to ensure that matrix effects or coeluting drugs do not impact quantitative assay performance. In this report, we describe efforts to ameliorate such effects in the absence of an isotopically labeled internal standard. Matrix effects are highly variable and heavily dependent on the physico-chemical properties of the substance. Although there is no universal solution to their resolution, conditions at the electrospray interface can mitigate these issues. Using this approach, the LC–MS/MS assay was fully validated and limits of detection and quantitation of 0.1 and 0.5 ng/mL suvorexant were achieved in blood.

Development and Validation of a Lateral Flow Immunoassay Test Kit for Dual Detection of Casein and β-Lactoglobulin Residues

2016 ◽  
Vol 79 (3) ◽  
pp. 477-483 ◽  
Author(s):  
JONGKIT MASIRI ◽  
BRIANDA BARRIOS-LOPEZ ◽  
LORA BENOIT ◽  
JOSHUA TAMAYO ◽  
JEFFREY DAY ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Rapid Test ◽  
Lateral Flow ◽  
Test Method ◽  
Cow’S Milk ◽  
Lateral Flow Immunoassay ◽  
Screening Methods ◽  
Cow's Milk ◽  
Test Kit ◽  
Β Lactoglobulin

ABSTRACT Allergies to cow's milk are very common and can present as life-threatening anaphylaxis. Consequently, food labeling legislation mandates that foods containing milk residues, including casein and/or β-lactoglobulin, provide an indication of such on the product label. Because contamination with either component independent of the other can occur during food manufacturing, effective allergen management measures for containment of milk residues necessitates the use of dual screening methods. To assist the food industry in improving food safety practices, we have developed a rapid lateral flow immunoassay test kit that reliably reports both residues down to 0.01 μg per swab and 0.1 ppm of protein for foods. The assay utilizes both sandwich and competitive format test lines and is specific for bovine milk residues. Selectivity testing using a panel of matrices with potentially interfering substances, including commonly used sanitizing agents, indicated reduction in the limit of detection by one-to fourfold. With food, residues were easily detected in all cow's milk–based foods tested, but goat and sheep milk residues were not detected. Specificity analysis revealed no cross-reactivity with common commodities, with the exception of kidney beans when present at high concentrations (>1%). The development of a highly sensitive and rapid test method capable of detecting trace amounts of casein and/or β-lactoglobulin should aid food manufacturers and regulatory agencies in monitoring for milk allergens in environmental and food samples.

scholarly journals Comparison of Two Immunoassay Screening Methods and a LC-MS/MS in Detecting Traditional and Designer Benzodiazepines in Urine

Molecules ◽  
2021 ◽  
Vol 27 (1) ◽  
pp. 112
Author(s):  
Brian Rossi ◽  
Francesca Freni ◽  
Claudia Vignali ◽  
Cristiana Stramesi ◽  
Giancarlo Collo ◽  
...  
Keyword(s):  
Forensic Toxicology ◽  
Cross Reactivity ◽  
Screening Methods ◽  
Tandem Mass ◽  
Before And After ◽  
Tandem Mass Spectrometric ◽  
Liquid Chromatographic ◽  
Clinical And Forensic Toxicology ◽  
Higher Sensitivity ◽  
Designer Benzodiazepines

Sensitive and specific immunoassay screening methods for the detection of benzodiazepines in urine represent an important prerequisite for routine analysis in clinical and forensic toxicology. Moreover, emerging designer benzodiazepines force labs to keep their methodologies updated, in order to evaluate the reliability of the immunochemical techniques. This study aimed at evaluating the sensitivity and specificity of two different immunoassay methods for the detection of benzodiazepines in urine, through a comparison with the results obtained by a newly developed liquid chromatographic tandem mass spectrometric (LC-MS/MS) procedure. A cohort of authentic urine samples (N = 501) were processed, before and after a hydrolysis procedure, through two immunoassays and an LC-MS/MS method. The LC-MS/MS target procedure was optimized for monitoring 25 different molecules, among traditional and designer benzodiazepines, including some metabolites. At least one of the monitored substances was detected in 100 out of the 501 samples. A good specificity was observed for the two immunoassays (>0.99), independently of the cut-offs and the sample hydrolysis. The new kit demonstrated a fairly higher sensitivity, always higher than 0.90; in particular, a high cross-reactivity of the new immunoassay was observed for samples that tested positive for lorazepam and 7-aminoclonazepam. The two immunoassays appeared adequate to monitor not only traditional benzodiazepines but also new designer ones.

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