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Appetite stimulation with cannabis-based medicine and methods for assessment of glomerular filtration in older patients with medical illness: A study protocol. Basic Clin Pharmacol Toxicol 2023; 133:237-253. [PMID: 37314893 DOI: 10.1111/bcpt.13914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 05/05/2023] [Accepted: 06/07/2023] [Indexed: 06/16/2023]
Abstract
BACKGROUND AND AIM Malnutrition in older patients is linked to poor appetite. Cannabis-based medicine may have orexigenic properties in older patients, but this has to our knowledge never been investigated. In older patients, uncertainty applies to the accuracy of estimated glomerular filtration rate (eGFR) based on creatinine, which is crucial for medication prescribing. In older patients with poor appetite, the study aims (1) to assess the efficacy of Sativex® (8.1-mg delta-9-tetrahydrocannabinol [THC] and 7.5-mg cannabidiol [CBD]) to stimulate appetite and (2) to compare the performance of various GFR-estimates and measured-GFR (mGFR) for determining gentamicin clearance utilizing population pharmacokinetic (popPK) modelling methods. METHODS AND OBJECTIVES This study is composed of two substudies. Substudy 1 is an investigator-initiated single-center, double-blinded, randomized, placebo-controlled, superiority, cross-over study. Substudy 1 will recruit 17 older patients with poor appetite, who will also be invited to substudy 2. Substudy 2 is a single-dose pharmacokinetics study and will recruit 55 patients. Participants will receive Sativex® and placebo in substudy 1 and gentamicin with simultaneous measurements of GFR in substudy 2. The primary endpoints are as follows: Substudy 1-the difference in energy intake between Sativex® and placebo conditions; substudy 2- the accuracy of different eGFR equations compared to mGFR. The secondary endpoints include safety parameters, changes in the appetite hormones, total ghrelin and GLP-1 and subjective appetite sensations, and the creation of popPK models of THC, CBD, and gentamicin.
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Implementation of Mathematical Models to Predict New Cannabis Use by Urine Drug Testing: It Is Time to Move Forward. J Anal Toxicol 2021; 45:e15-e19. [PMID: 33876828 PMCID: PMC8272527 DOI: 10.1093/jat/bkab037] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 04/08/2021] [Accepted: 04/19/2021] [Indexed: 11/15/2022] Open
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New psychoactive substances (NPS) escape routine drug testing: a case report of phenibut. TOXICOLOGY COMMUNICATIONS 2020. [DOI: 10.1080/24734306.2020.1796342] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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Ethylene glycol: Evidence of glucuronidation in vivoshown by analysis of clinical toxicology samples. Drug Test Anal 2019; 11:1094-1108. [PMID: 30845374 PMCID: PMC6767423 DOI: 10.1002/dta.2584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2018] [Revised: 02/28/2019] [Accepted: 02/28/2019] [Indexed: 11/06/2022]
Abstract
In the search for improved laboratory methods for the diagnosis of ethylene glycol poisoning, the in vivo formation of a glucuronide metabolite of ethylene glycol was hypothesized. Chemically pure standards of the β‐O‐glucuronide of ethylene glycol (EG‐GLUC) and a deuterated analog (d4‐EG‐GLUC) were synthesized. A high‐performance liquid chromatography and tandem mass spectrometry method for determination of EG‐GLUC in serum after ultrafiltration was validated. Inter‐assay precision (%RSD) was 3.9% to 15.1% and inter‐assay %bias was −2.8% to 12.2%. The measuring range was 2–100 μmol/L (0.48–24 mg/L). Specificity testing showed no endogenous amounts in routine clinical samples (n = 40). The method was used to analyze authentic, clinical serum samples (n = 31) from patients intoxicated with ethylene glycol. EG‐GLUC was quantified in 15 of these samples, with a mean concentration of 6.5 μmol/L (1.6 mg/L), ranging from 2.3 to 15.6 μmol/L (0.55 to 3.7 mg/L). In five samples, EG‐GLUC was detected below the limit of quantification (2 μmol/L) and it was below the limit of detection in 11 samples (1 μmol/L). Compared to the millimolar concentrations of ethylene glycol present in blood after intoxications and potentially available for conjugation, the concentrations of EG‐GLUC found in clinical serum samples are very low, but comparable to concentrations of ethyl glucuronide after medium dose ethanol intake. In theory, EG‐GLUC has a potential value as a biomarker for ethylene glycol intake, but the pharmacokinetic properties, in vivo/vitro stability and the biosynthetic pathways of EG‐GLUC must be further studied in a larger number of patients and other biological matrices.
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Patients in medical treatment for attention deficit/hyperactivity disorder (ADHD): Are they at risk in drug screening? ACTA ACUST UNITED AC 2018; 11:333-340. [PMID: 30536198 DOI: 10.1007/s12402-018-0282-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 12/03/2018] [Indexed: 11/29/2022]
Abstract
The use of medicines to treat attention deficit/hyperactivity disorder (ADHD) has increased worldwide, including the use of amphetamine-based medicines or prodrugs that metabolise to amphetamine in vivo. At the same time, drugs-of-abuse testing by non-specific, point-of-care immunoassay methods ('quick tests') has increased. This article discusses the risk of 'false positive' results or post-analytical misinterpretations of results when immunoassays are used to analyse biological samples from ADHD patients. A rapid evidence review was conducted to identify studies that have focused on the risk of 'false positive' test results in immunoassay testing of patients treated with atomoxetine, bupropion, clonidine, guanfacine, methylphenidate, and modafinil. There is only evidence to suggest that bupropion should cause 'false positive' immunoassay results. However, there is a lack of systematic, updated evaluations and validations of cross-reactivity patterns for immunoassays in the literature. Advanced laboratory methods can distinguish the use of medicines from illicit amphetamine by stereospecific analysis of dextro- and levoamphetamine; however, these analytical services are not commonly available for routine drug testing. The present situation calls for more awareness, proper education and information on these critical ethical issues in drug testing, both for clinicians, other healthcare professionals involved in drug testing and for patients in medical treatment for ADHD. The pitfalls of immunoassays due to cross-reactivity and insufficient specificity/sensitivity can have serious negative consequences for patients safety with regard to incorrect laboratory drug-testing results. Consequently, confirmatory laboratory analysis should always be performed for 'presumptive' positive immunoassay screening results.
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Characteristics of opioid-maintained clients smoking fentanyl patches: The importance of confirmatory drug analysis illustrated by a case series and mini-review. Drug Test Anal 2018; 10:917-926. [PMID: 29675893 DOI: 10.1002/dta.2397] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 04/12/2018] [Accepted: 04/12/2018] [Indexed: 11/09/2022]
Abstract
The increase in opioid prescribing in many European countries over the last decade has raised concerns about associated diversion, overdose, and mortality. Fentanyl is one of these synthetic opioids that is typically prescribed as a transdermal patch for pain that requires continuous pain relief and has been the focus of investigation due to reports of overdose and death. We report a case series of 14 drug addiction treatment entrants, who entered treatment in a service located in the region of Southern Denmark from August 2015 to December 2015 for smoking fentanyl patches. Clients presented with difficulties breathing and pains in the lungs. The clients had a history of past opioid use, including heroin. Relapses resulted in treatment disengagement. Immunoassays for fentanyl were used in the service. In some cases, false negative results occurred. Clients' urine samples were subsequently analysed in a collaborating laboratory. Seven clients tested positive for fentanyl. One client was positive for both fentanyl and heroin. Analyses were also positive for other opioids and metabolites in 6 clients, predominantly codeine and oxycodone. Results from confirmatory analysis contributed to clearer insights into clients' drug histories, which facilitated personalised care plans consisting of opioid agonist therapy informed by confirmed drug use. In Denmark, prescription levels of fentanyl are high, which has been accompanied by observations of diversion and smoking in a smaller population. In addition to revision of inappropriate prescribing to reduce diversion, we recommend increased reliance upon confirmatory drug analysis in the addiction treatment sector in Denmark.
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Tampering of opioid analgesics: a serious challenge for public health? Addiction 2016; 111:1701-2. [PMID: 27273814 DOI: 10.1111/add.13436] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 04/18/2016] [Accepted: 04/21/2016] [Indexed: 12/16/2022]
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Identification of a new psychoactive substance in seized material: the synthetic opioid N-phenyl-N-[1-(2-phenethyl)piperidin-4-yl]prop-2-enamide (Acrylfentanyl). Drug Test Anal 2016; 9:415-422. [PMID: 27476446 PMCID: PMC5396312 DOI: 10.1002/dta.2046] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Revised: 07/21/2016] [Accepted: 07/26/2016] [Indexed: 11/07/2022]
Abstract
Among the new psychoactive substances (NPS) that have recently emerged on the market, many of the new synthetic opioids have shown to be particularly harmful. A new synthetic analogue of fentanyl, N-phenyl-N-[1-(2-phenethyl)piperidin-4-yl]prop-2-enamide (acrylfentanyl), was identified in powder from a seized capsule found at a forensic psychiatric ward in Denmark. Gas chromatography with mass spectrometry (GC-MS) identified a precursor to synthetic fentanyls, N-phenyl-1-(2-phenylethyl)piperidin-4-amine; however, the precursor 1-(2-phenethyl)piperidin-4-one, was not detected. Analysis of the electron impact mass spectrum of the main, unknown chromatographic peak (GC) tentatively identified an acryloyl analogue of fentanyl. Further analyses by quadrupole time-of-flight high resolution mass spectrometry (QTOF-MS), matrix-assisted laser ionization Orbitrap mass spectrometry (MALDI-Orbitrap-MS), nuclear magnetic resonance spectroscopy (NMR), and infra-red spectroscopy (IR) confirmed the presence of acrylfentanyl (also known as acryloylfentanyl). Quantitative analysis with liquid chromatography and triple quadrupole mass spectrometry (LC-MS/MS) determined the content of acrylfentanyl in the powder, equal to 88.3 mass-% acrylfentanyl hydrochloride. An impurity observed by NMR was identified as triethylamine hydrochloride. Acrylfentanyl is sold on the Internet as a 'research chemical'. Like other synthetic fentanyls, such as acetylfentanyl, it poses a serious risk of fatal intoxication. Copyright © 2016 The Authors. Drug Testing and Analysis Published by John Wiley & Sons Ltd.
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How Resistant to Tampering are Codeine Containing Analgesics on the Market? Assessing the Potential for Opioid Extraction. Pain Ther 2016; 5:187-201. [PMID: 27295264 PMCID: PMC5130903 DOI: 10.1007/s40122-016-0053-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Indexed: 01/08/2023] Open
Abstract
Introduction Misuse of opioid analgesics, in combination with diversion, dependence, and fatal overdoses, presents a serious problem for public health, which affects many countries worldwide. Within this context, tampering with opioids has been associated with serious harm. The aim of the present study was to assess the tampering potential of codeine combination analgesics on the market (containing codeine/non-opioid analgesics) by the extraction of codeine. Methods Codeine was extracted from three combination formulations sold lawfully from licensed pharmacies without a medical prescription in Denmark and the UK. Extraction of codeine followed tampering procedures available on the Internet. The amounts of codeine and accompanying non-opioid analgesics in tampering products were analysed with liquid chromatography and tandem mass spectrometry (LC–MS/MS). Results LC–MS/MS showed recoveries of the total amounts of codeine in tampering products of 81–84% from Product 1 (codeine/acetylsalicylic acid); 61–67% from Product 2 (codeine/ibuprofen); and 42–71% from Product 3 (codeine/paracetamol). Recoveries of non-opioid analgesics ranged between: 57–73% acetylsalicylic acid; 5.5–8.5% ibuprofen, and 5.0–9.2% paracetamol. Conclusion With the tampering procedures used, high amounts of codeine were separated from the accompanying analgesics in some, but not in all of the codeine containing formulations. Evidence-based medicine regulation, treatment for opioid dependence, and information to minimise risks to the public are essential components of an effective public health strategy to address the harms of tampering and misuse. Funding Marie Pedersen and Jensine Heiberg Foundation.
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Gamma‐hydroxybutyrate and cocaine intoxication in a Danish child. Clin Case Rep 2016; 4:228-31. [PMID: 27014439 PMCID: PMC4771861 DOI: 10.1002/ccr3.492] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2015] [Revised: 11/25/2015] [Accepted: 12/12/2015] [Indexed: 11/29/2022] Open
Abstract
GHB intoxication must be considered in children with coma and a suspicion of drug intoxication. Furthermore, mixed intoxication with several substances and the possibility of unpredictable symptom profiles should be anticipated to ensure optimal symptomatic treatment of patients.
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NT-proBNP on Cobas h 232 in point-of-care testing: Performance in the primary health care versus in the hospital laboratory. Scandinavian Journal of Clinical and Laboratory Investigation 2015; 75:602-9. [PMID: 26305423 DOI: 10.3109/00365513.2015.1066846] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND NT-proBNP may be useful for ruling out heart failure in primary health care. In this study we examined the analytical quality of NT-proBNP in primary health care on the Cobas h 232 point-of-care instrument compared with measurements performed in a hospital laboratory. MATERIALS AND METHODS Blood samples requested for NT-proBNP were collected in primary health care (n = 95) and in a hospital laboratory (n = 107). NT-proBNP was measured on-site on Cobas h 232 instruments both in primary health care centres and at the hospital laboratory and all samples were also analyzed with a comparison method at the hospital. Precision, trueness, accuracy, and lot-variation were determined at different concentration levels and evaluated according to acceptance criteria. Furthermore user-friendliness was assessed by questionnaires. RESULTS For Cobas h 232 repeatability CV was 8.5-10.7% in the hospital setting and 5.3-10.0% in the primary health care and within the analytical quality specifications, but higher than with the comparison method (< 4%). NT-proBNP results obtained in primary health care were significantly higher than by the hospital comparison method (bias ranged from 14.3-23.7%), whereas there was no significant bias when Cobas h 232 was used in the hospital setting (bias ranged from - 4.9 to 7.0%). User-friendliness of Cobas h 232 was overall acceptable. CONCLUSION Cobas h 232 point-of-care instrument for measurement of NT-proBNP performed satisfactorily with regard to precision, user-friendliness, and lot-variation. A decrease in NT-proBNP levels observed in samples transported to a central laboratory needs further attention and investigation.
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Analysis of Urinary Biomarkers for Smoking Crack Cocaine: Results of a Danish Laboratory Study. J Anal Toxicol 2015; 39:451-9. [DOI: 10.1093/jat/bkv035] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Synthetic growth hormone releasers detected in seized drugs: new trends in the use of drugs for performance enhancement. Addiction 2015; 110:368-9. [PMID: 25602046 DOI: 10.1111/add.12785] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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The composition of anabolic steroids from the illicit market is largely unknown: implications for clinical case reports. QJM 2014; 107:597-8. [PMID: 24811551 DOI: 10.1093/qjmed/hcu101] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Identification and characterization by LC-UV-MS/MS of melanotan II skin-tanning products sold illegally on the Internet. Drug Test Anal 2014; 7:164-72. [DOI: 10.1002/dta.1655] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Revised: 03/07/2014] [Accepted: 03/08/2014] [Indexed: 01/19/2023]
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Online marketing of synthetic peptide hormones: poor manufacturing, user safety, and challenges to public health. Drug Test Anal 2014; 6:396-8. [PMID: 24639203 DOI: 10.1002/dta.1636] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Revised: 02/13/2014] [Accepted: 02/14/2014] [Indexed: 02/02/2023]
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Identification of a new metabolite of GHB: gamma-hydroxybutyric acid glucuronide. J Anal Toxicol 2013; 37:291-7. [PMID: 23612681 DOI: 10.1093/jat/bkt027] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Gamma-hydroxybutyric acid (GHB) is an important analyte in clinical and forensic toxicology with a narrow detection window of 3-6 h. In the search of improved detection methods, the existence in vivo of a glucuronated GHB metabolite (GHB-GLUC) was hypothesized. Chemically pure standards of GHB-GLUC and a deuterated analogue for chromatography were synthesized. Liquid chromatography and tandem mass spectrometry were used for targeted analysis in anonymous clinical urine samples (n = 50). GHB-GLUC was found in concentrations ranging from 0.11 to 5.0 µg/mL (mean: 1.3 ± 1.2 µg/mL). Thus far, this is the first report of a GHB glucuronide detected in biological samples. Given that glucuronides generally have longer half-life values than their corresponding free drugs, GHB-GLUC should theoretically be a biomarker of GHB intoxication. It is also proposed that the hitherto unexplained reports of elevated GHB concentrations in some biological samples, which has caused the setting of a relatively high cutoff value (10 µg/mL), represent total GHB measurements (sum of free GHB and actively chemically hydrolyzed GHB-GLUC). To address these challenges, the present study must be followed by comprehensive pharmacokinetic and stability studies after the controlled administration of GHB.
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Synthesis and stability study of a new major metabolite of γ-hydroxybutyric acid. Beilstein J Org Chem 2013; 9:641-6. [PMID: 23616808 PMCID: PMC3628683 DOI: 10.3762/bjoc.9.72] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Accepted: 03/11/2013] [Indexed: 01/10/2023] Open
Abstract
γ-Hydroxybutanoic acid (GHB) is used as a date-rape drug, which renders the victims unconscious and defenceless. Intoxications are very difficult to detect for forensic scientists due to rapid metabolism to endogenous levels of GHB. We recently discovered a new major metabolite, 2, of GHB (1) that could potentially extend the analytical detection window for GHB intoxications. Herein we disclose synthetic procedures based on a Koenigs-Knorr glucuronidation approach that provides GHB glucuronide 2 and a deuterium-labelled analogue d 4-2 of high purity suitable for analytical chemistry. In addition, we have assessed the stability of GHB glucuronide 2 by mimicking the natural pH range for urine, which is of importance in the development of new analytical methods. Using NMR we show that GHB glucuronide 2 is highly stable towards aqueous hydrolysis within the pH range normally observed for urine even at elevated temperature.
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Methylphenidate is Distinguished from Amphetamine in Drug-of-Abuse Testing. J Anal Toxicol 2012; 36:538-9. [DOI: 10.1093/jat/bks056] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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[Is testing for "angel dust" meaningful?]. Ugeskr Laeger 2011; 173:1379. [PMID: 21776627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
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Quantification of Fentanyl in Human Serum by Column-Switching Liquid Chromatography and Tandem Mass Spectrometry. ACTA ACUST UNITED AC 2011. [DOI: 10.4172/1948-593x.1000052] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Column-switching HPLC–MS/MS analysis of ropivacaine in serum, ultrafiltrate and drainage blood for validating the safety of blood reinfusion. J Chromatogr B Analyt Technol Biomed Life Sci 2010; 878:76-82. [DOI: 10.1016/j.jchromb.2009.11.028] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2009] [Revised: 11/13/2009] [Accepted: 11/15/2009] [Indexed: 10/20/2022]
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Therapeutic drug monitoring of flecainide in serum using high-performance liquid chromatography and electrospray mass spectrometry. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 2000; 746:249-54. [PMID: 11076078 DOI: 10.1016/s0378-4347(00)00343-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
High-performance liquid chromatography with electrospray mass spectrometry (LC-MS) was used for analysis of the drug flecainide in serum. The clean-up was performed by solid-phase extraction, and an aromatic ring positional isomer was used as internal standard. Results from method validation on spiked serum samples showed excellent reproducibility; intra- and inter-assay variations (C.V.% and %Bias) were less than 6% within the therapeutic concentration range of the drug (0.2-1.0 microg/ml). Linearity was demonstrated from 0.05 to 2.0 microg/ml. The limit of detection and quantification was 0.025 and 0.05 microg/ml, respectively. Due to the high selectivity of the mass spectrometric detection, no interferences were observed. Results from clinical samples (n=18) from patients in treatment with Tambocor (flecainide acetate) showed excellent correlation with parallel data obtained from a method based on high-performance liquid chromatography (HPLC) with fluorescence detection after liquid/liquid extraction. The chromatographic separation of flecainide and internal standard was improved compared to earlier HPLC methods. The methodology is simple, accurate and requires only 0.25 ml of sample. It is a well suited method for routine therapeutic drug monitoring in a hospital or clinical chemistry laboratory.
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Plasticizers in total diet samples, baby food and infant formulae. FOOD ADDITIVES AND CONTAMINANTS 2000; 17:133-41. [PMID: 10793844 DOI: 10.1080/026520300283487] [Citation(s) in RCA: 194] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The plasticizers di-n-butylphthalate (DBP), butylbenzylphthalate (BBP), di-2-(ethylhexyl)phthalate (DEHP) and di-2-(ethylhexyl)adipate (DEHA) were analysed in 29 total diet samples, in 11 samples of baby food and in 11 samples of infant formulae. In all of the total diet samples the presence of one or more of the plasticizers was demonstrated. Maximum and minimum mean concentrations in the total diet samples were: 0.09-0.19 mg DBP/kg, 0.017-0.019 mg BBP/kg, 0.11-0.18 mg DEHP/kg and 0.13-0.14 mg DEHA/kg. One or more of the phthalates was also found in about 50% of the samples of baby food as well as in infant formulae. The calculated mean maximum intakes of the individual compounds from the total diet samples were below 10% of the restrictions proposed by the EU Scientific Committee for Food (SCF), and the spread in individual intakes was considerable. DEHP was the plasticizer determined most frequently and contributed the highest fraction of its tolerable daily intake (TDI). Hence, the maximum calculated intake of DEHP from single samples of the foodstuffs analysed could be up to one-third of the TDI. The calculated mean intake of DEHA was about 1% of the TDI with a maximum value of 13% of the TDI. Violations of the restrictions proposed by the EU Scientific Committee for Food (SCF) in the form of TDI values or specific migration limits were not found in this investigation.
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Validation of urine drug-of-abuse testing methods for ketobemidone using thin-layer chromatography and liquid chromatography-electrospray mass spectrometry. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 1999; 736:103-13. [PMID: 10676989 DOI: 10.1016/s0378-4347(99)00449-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
High-performance thin-layer chromatography (TLC) with visual detection (post-chromatographic derivatization) was used in screening for the drug ketobemidone in human urine samples. High-performance liquid chromatography with electrospray mass spectrometry (LC-ESI-MS) was used for final confirmation of the result. The clean-up was performed by mixed-mode solid-phase extraction, and nalorphine was used as internal standard. A screening cut-off for TLC was established at 0.2 microg/ml. The mean recovery for LC-MS was 91% (n=60) with coefficients of variation (C.V.) in the range of 7 to 16%. Qualifying fragment ions of ketobemidone (m/z 190, 201 and 230) were generated by up front collision-induced dissociation (CID) on a single quadrupole instrument. Relative ion intensities were within +/- 15% deviation compared with standards in the same batch. The limit of detection for LC-MS was 0.025 microg/ml. Positive clinical samples from drug abusers (n=10) had concentrations in the range 0.07 to 3.2 microg/ml, which could be determined by LC-MS without matrix interference. During screening of unknown clinical samples (n=27) the results from TLC was in agreement with LC-MS data. After acid hydrolysis of conjugates in clinical samples the analyte response of ketobemidone and norketobemidone was increased by a factor of approximately two and twelve, respectively. A qualitative GC-MS technique was demonstrated for the detection of the spasmolyticum A29 (N,N-dimethyl-4,4-diphenyl-3-buten-2-amine), which can be found in a preparation combined with ketobemidone (Ketogan).
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Determination of 11-nor-delta9-tetrahydrocannabinol-9-carboxylic acid in urine using high-performance liquid chromatography and electrospray ionization mass spectrometry. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 1999; 732:155-64. [PMID: 10517232 DOI: 10.1016/s0378-4347(99)00276-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
High-performance liquid chromatography with electrospray ionization mass spectrometry was used to determine 11-nor-delta9-tetrahydrocannabinol-9-carboxylic acid (THC-COOH) in urine. After basic hydrolysis of conjugates, the compound was extracted using SPEC-PLUS-3ML-C18 solid-phase extraction columns. A deuterium labelled internal standard (d3-THC-COOH) was added prior to hydrolysis. Separation was performed on a reversed-phase Zorbax Eclipse XDB-C8 analytical column (150x3.0 mm I.D.) using a gradient program from 60 to 80% acetonitrile (4 mM formic acid) at a flow-rate of 0.5 ml/min. The compounds were detected by single ion monitoring of m/z 345 and m/z 348 for the protonated molecules [THC-COOH+H]+ and [d3-THC-COOH+H]+, respectively. The precision and accuracy were tested on spiked urine samples in the range 2.5-125 ng/ml. The mean recovery was 95% (n = 58), coefficients of variations were 2.2-4.3% and the limit of detection 2 ng/ml. Diagnostic qualifying ions of THC-COOH (m/z 327 and m/z 299) and d3-THC-COOH (m/z 330) were generated using up-front collision-induced dissociation. The relative ion intensities in clinical samples (n = 21) were within +/-20% deviation compared with standards. Using this tolerance and the presence of the ions m/z 327 and m/z 299 at the correct retention times as the acceptance criteria for identification of THC-COOH positive samples, the limit of detection was 15 ng/ml. The LC-MS method complies with the current recommendations on drugs of abuse testing, in which mass spectrometric detection is emphasized.
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Specific migration of di-(2-ethylhexyl)adipate (DEHA) from plasticized PVC film: results from an enforcement campaign. FOOD ADDITIVES AND CONTAMINANTS 1998; 15:600-8. [PMID: 9829046 DOI: 10.1080/02652039809374687] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
A control campaign on the correct labelling of plasticized PVC film according to current legislation on food contact materials has been performed. Analytical methods based on the isotope dilution technique were developed. For enforcement purposes, the films were exposed to the official food simulant, olive oil, followed by clean-up using size exclusion chromatography and final determination of di-(2-ethylhexyl) adipate (DEHA) by combined capillary gas chromatography and mass spectrometry (GC-MS). In the initial screening, the samples were exposed to the alternative food simulant, isooctane, and DEHA could be determined by GC-MS without further clean-up. A good consistency between results from the two different methods was obtained. During the campaign, 49 samples of PVC films, the majority intended for use in retail shops, were sampled from importers and wholesalers by the Municipal Food Control Units. Initially, all films were screened for the migration into isooctane (exposed 2 h at 40 degrees C) of DEHA and other potentially present low molecular weight plasticizers using full scanning mass spectrometry. Films showing a substantial migration of DEHA were further tested with olive oil according to the declared field of application (exposed for 10 days at 40 degrees C). In 47 of the 49 films the migrate contained a substantial amount of DEHA. In 46 films the migration exceeded the specific migration limit of 3 mg/dm2 after use of the relevant reduction factor given in legislation. However, because of the general uncertainty of the analytical method and because the variation in the thickness of the films was calculated to be 1 mg/dm2, the action limit in this campaign was 4 mg/cm2. A migration higher than this action limit was found in 42 films (89% of the samples) and these films were deemed to be illegal according to their present declared field of application as given by their labelling. In a few cases, some migration of the plasticizer di-n-butyl phthalate was seen.
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On the proton affinity of some α-amino acids and the theory of the kinetic method. ACTA ACUST UNITED AC 1994. [DOI: 10.1039/p29940001029] [Citation(s) in RCA: 86] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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