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Chambers M, Giffen-Lemieux JE, Musah RA. Rapid Detection and Quantification of Hallucinogenic Salvinorin A in Commercial Salvia divinorum Products by DART-HRMS. ACS OMEGA 2023; 8:761-770. [PMID: 36643502 PMCID: PMC9835517 DOI: 10.1021/acsomega.2c06106] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 11/17/2022] [Indexed: 06/17/2023]
Abstract
In recent years, national laboratories have identified several plant-derived materials as concerns to public health because of their psychoactive effects, potential for abuse, and the lack of federal regulation of their use. One of these is Salvia divinorum (aka Salvia), which has received focused attention due to its increasing recreational use and the ease by which it can be acquired. Traditional chromatographic approaches for the detection of the major psychoactive component of Salvia (i.e., salvinorin A) typically require time-consuming sample pretreatment prior to identifying the presence of salvinorin A in plant material unknowns. In this study, direct analysis in real time-high-resolution mass spectrometry (DART-HRMS) was used to rapidly screen for Salvia plant material. This approach facilitated the analysis of bulk material in its native form, thereby bypassing sample pretreatment steps. In addition, a validated DART-HRMS method was developed for the quantification of salvinorin A in commercial Salvia products (e.g., raw plant materials, enhanced leaf extracts). In this regard, cholesterol was found to be a suitable internal standard. The average salvinorin A content in raw Salvia leaves was determined to be 1.54 mg/g, while the salvinorin A quantified in enhanced Salvia leaf extracts was between 13.0 and 53.2 mg/g.
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Ahmad SM, Gonçalves OC, Oliveira MN, Neng NR, Nogueira JMF. Application of Microextraction-Based Techniques for Screening-Controlled Drugs in Forensic Context-A Review. Molecules 2021; 26:2168. [PMID: 33918766 PMCID: PMC8070059 DOI: 10.3390/molecules26082168] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 04/03/2021] [Accepted: 04/06/2021] [Indexed: 01/12/2023] Open
Abstract
The analysis of controlled drugs in forensic matrices, i.e., urine, blood, plasma, saliva, and hair, is one of the current hot topics in the clinical and toxicological context. The use of microextraction-based approaches has gained considerable notoriety, mainly due to the great simplicity, cost-benefit, and environmental sustainability. For this reason, the application of these innovative techniques has become more relevant than ever in programs for monitoring priority substances such as the main illicit drugs, e.g., opioids, stimulants, cannabinoids, hallucinogens, dissociative drugs, and related compounds. The present contribution aims to make a comprehensive review on the state-of-the art advantages and future trends on the application of microextraction-based techniques for screening-controlled drugs in the forensic context.
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Affiliation(s)
- Samir M. Ahmad
- Centro de Química Estrutural, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal; (O.C.G.); (M.N.O.)
- Molecular Pathology and Forensic Biochemistry Laboratory, CiiEM, Campus Universitário—Quinta da Granja, Monte da Caparica, 2829-511 Caparica, Portugal
- Forensic and Psychological Sciences Laboratory Egas Moniz, Campus Universitário—Quinta da Granja, Monte da Caparica, 2829-511 Caparica, Portugal
| | - Oriana C. Gonçalves
- Centro de Química Estrutural, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal; (O.C.G.); (M.N.O.)
| | - Mariana N. Oliveira
- Centro de Química Estrutural, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal; (O.C.G.); (M.N.O.)
| | - Nuno R. Neng
- Centro de Química Estrutural, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal; (O.C.G.); (M.N.O.)
- Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal
| | - José M. F. Nogueira
- Centro de Química Estrutural, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal; (O.C.G.); (M.N.O.)
- Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal
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Ligor T, Zawadzka J, Strączyński G, González Paredes RM, Wenda-Piesik A, Ratiu IA, Muszytowski M. Searching for Potential Markers of Glomerulopathy in Urine by HS-SPME-GC×GC TOFMS. Molecules 2021; 26:molecules26071817. [PMID: 33804943 PMCID: PMC8036251 DOI: 10.3390/molecules26071817] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 03/19/2021] [Accepted: 03/21/2021] [Indexed: 11/23/2022] Open
Abstract
Volatile organic compounds (VOCs) exiting in urine are potential biomarkers of chronic kidney diseases. Headspace solid phase microextraction (HS-SPME) was applied for extraction VOCs over the urine samples. Volatile metabolites were separated and identified by means of two-dimensional gas chromatography and time of flight mass spectrometry (GC × GC TOF MS). Patients with glomerular diseases (n = 27) and healthy controls (n = 20) were recruited in the study. Different VOCs profiles were obtained from patients and control. Developed methodology offers the opportunity to examine the metabolic profile associated with glomerulopathy. Four compounds found in elevated amounts in the patients group, i.e., methyl hexadecanoate; 9-hexadecen-1-ol; 6,10-dimethyl-5,9-undecadien-2-one and 2-pentanone were proposed as markers of glomerular diseases.
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Affiliation(s)
- Tomasz Ligor
- Department of Environmental Chemistry and Bioanalytics, Faculty of Chemistry, Nicolaus Copernicus University, 87-100 Toruń, Poland
- Interdisciplinary Centre of Modern Technologies, Nicolaus Copernicus University, 87-100 Toruń, Poland;
- Correspondence:
| | - Joanna Zawadzka
- Department of Nephrology, Diabetology and Internal Medicine, Nicolaus Copernicus University, Rydygier Hospital, 87-100 Toruń, Poland; (J.Z.); (M.M.)
| | | | - Rosa M. González Paredes
- Department of Analytical Chemistry, Nutrition and Food Sciences, University of Salamanca, 37008 Salamanca, Spain;
| | - Anna Wenda-Piesik
- Department of Plant Growth Principles and Experimental Methods, UTP University of Science and Technology, 85-796 Bydgoszcz, Poland;
| | - Ileana Andreea Ratiu
- Interdisciplinary Centre of Modern Technologies, Nicolaus Copernicus University, 87-100 Toruń, Poland;
- “Raluca Ripan” Institute for Research in Chemistry, Babes-Bolyai University, 30 Fantanele, RO-400239 Cluj Napoca, Romania
| | - Marek Muszytowski
- Department of Nephrology, Diabetology and Internal Medicine, Nicolaus Copernicus University, Rydygier Hospital, 87-100 Toruń, Poland; (J.Z.); (M.M.)
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Psychoactive Substances of Natural Origin: Toxicological Aspects, Therapeutic Properties and Analysis in Biological Samples. Molecules 2021; 26:molecules26051397. [PMID: 33807728 PMCID: PMC7961374 DOI: 10.3390/molecules26051397] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 02/28/2021] [Accepted: 03/02/2021] [Indexed: 12/14/2022] Open
Abstract
The consumption of new psychoactive substances (NPSs) has been increasing, and this problem affects several countries worldwide. There is a class of NPSs of natural origin, consisting of plants and fungi, which have a wide range of alkaloids, responsible for causing relaxing, stimulating or hallucinogenic effects. The consumption of some of these substances is prompted by religious beliefs and cultural reasons, making the legislation very variable or even ambiguous. However, the abusive consumption of these substances can present an enormous risk to the health of the individuals, since their metabolism and effects are not yet fully known. Additionally, NPSs are widely spread over the internet, and their appearance is very fast, which requires the development of sophisticated analytical methodologies, capable of detecting these compounds. Thus, the objective of this work is to review the toxicological aspects, traditional use/therapeutic potential and the analytical methods developed in biological matrices in twelve plant specimens (Areca catechu, Argyreia nervosa, Ayahuasca, Catha edulis, Datura stramonium, Lophophora williamsii, Mandragora officinarum, Mitragyna speciosa, Piper methysticum Forst, Psilocybe, Salvia divinorum and Tabernanthe iboga).
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Pharmacokinetics and Pharmacodynamics of Salvinorin A and Salvia divinorum: Clinical and Forensic Aspects. Pharmaceuticals (Basel) 2021; 14:ph14020116. [PMID: 33546518 PMCID: PMC7913753 DOI: 10.3390/ph14020116] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 01/26/2021] [Accepted: 01/29/2021] [Indexed: 01/13/2023] Open
Abstract
Salvia divinorum Epling and Játiva is a perennial mint from the Lamiaceae family, endemic to Mexico, predominantly from the state of Oaxaca. Due to its psychoactive properties, S. divinorum had been used for centuries by Mazatecans for divinatory, religious, and medicinal purposes. In recent years, its use for recreational purposes, especially among adolescents and young adults, has progressively increased. The main bioactive compound underlying the hallucinogenic effects, salvinorin A, is a non-nitrogenous diterpenoid with high affinity and selectivity for the κ-opioid receptor. The aim of this work is to comprehensively review and discuss the toxicokinetics and toxicodynamics of S. divinorum and salvinorin A, highlighting their psychological, physiological, and toxic effects. Potential therapeutic applications and forensic aspects are also covered in this review. The leaves of S. divinorum can be chewed, drunk as an infusion, smoked, or vaporised. Absorption of salvinorin A occurs through the oral mucosa or the respiratory tract, being rapidly broken down in the gastrointestinal system to its major inactive metabolite, salvinorin B, when swallowed. Salvinorin A is rapidly distributed, with accumulation in the brain, and quickly eliminated. Its pharmacokinetic parameters parallel well with the short-lived psychoactive and physiological effects. No reports on toxicity or serious adverse outcomes were found. A variety of therapeutic applications have been proposed for S. divinorum which includes the treatment of chronic pain, gastrointestinal and mood disorders, neurological diseases, and treatment of drug dependence. Notwithstanding, there is still limited knowledge regarding the pharmacology and toxicology features of S. divinorum and salvinorin A, and this is needed due to its widespread use. Additionally, the clinical acceptance of salvinorin A has been hampered, especially due to the psychotropic side effects and misuse, turning the scientific community to the development of analogues with better pharmacological profiles.
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Weggler BA, Gruber B, Teehan P, Jaramillo R, Dorman FL. Inlets and sampling. SEP SCI TECHNOL 2020. [DOI: 10.1016/b978-0-12-813745-1.00005-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Soto-Restrepo V, Taborda-Ocampo G, Garzón-Méndez W. Salvinorina A: terpeno alucinógeno presente en Salvia divinorum Epling & Játiva. COLOMBIA FORENSE 2017. [DOI: 10.16925/cf.v4i1.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Tema y alcance: el objetivo de esta revisión es presentar los estudios químicos que se han realizado sobre Salvia divinorum E&J en estos últimos años.
Características: desde la década de 1990 hasta hoy se ha incrementado la distribución y el uso de Salvia divinorum E&J para “fines recreativos”, debido a sus efectos alucinógenos y a su fácil acceso. Sus efectos en el organismo se han relacionado con las de otras sustancias como: delta-9-THC en la marihuana, DMT, LSD , MDMA, PCP y ketamina.
Hallazgos: las investigaciones químicas realizadas en otros países sobre Salvia divinorum E&J se enfocan en los procesos de extracción, determinación, cuantificación, análisis y biosíntesis de Salvinorina A, compuesto químico al cual se le atribuye la bioactividad de la planta. Este compuesto es considerado como uno de los alucinógenos más potentes de origen natural, además de ser química y estructuralmente único, puesto que fue el primer diterpeno conocido con actividad psicoactiva.
Conclusiones: la presente revisión encontró que en los últimos años las investigaciones químicas en Salvia divinorum E&J están enfocadas a través del uso de cromatografía de gases y cromatografía líquida en diversas matrices como hojas, sangre, orina y agua, con el fin de determinar la Salvinorina A y otros metabolitos presentes en la planta. En una de las investigaciones, comprobaron por RMN y HR-ESI-MS que la biosíntesis de Salvinorina A está dada por la ruta metabólica del ácido mevalónico y la ruta del metileritritol fosfato, las cuales corresponden a las rutas metabólicas para la biosíntesis de terpenos.
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Abstract
The identification and quantitation of the main psychoactive component of Salvia divinorum (salvinorin A) in biological specimens are crucial in forensic and clinical toxicology. Despite all the efforts made, its uncontrolled abuse has increased quickly, exposing its users' health to serious risks both in the short and long term. The use of alternative biological matrices in toxicological analyzes can be advantageous as complementary postmortem samples, or in situations when neither blood nor urine can be collected; they may be useful tools in those determinations, providing important information about prior exposure. The aim of this article is to present a brief summary of legal aspects of Salvia divinorum and salvinorin A, including the methods used for the determination of the latter in biological matrices.
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Salvinorin A content in legal high products of Salvia divinorum sold in Mexico. Forensic Sci Int 2015; 249:197-201. [DOI: 10.1016/j.forsciint.2015.01.038] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Revised: 01/15/2015] [Accepted: 01/26/2015] [Indexed: 11/17/2022]
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Application of mixed cloud point extraction for the analysis of six flavonoids in Apocynum venetum leaf samples by high performance liquid chromatography. J Pharm Biomed Anal 2015; 107:273-9. [DOI: 10.1016/j.jpba.2015.01.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Revised: 12/29/2014] [Accepted: 01/04/2015] [Indexed: 11/23/2022]
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Abstract
Since the complexity origin of biological samples, the research trends have been directed to the development of new miniaturized sample preparation techniques. This review provides a comprehensive survey of past and present microextraction methods followed by GC analysis for preconcentration and determination of various analytes in urine samples. These techniques have been classified in three general groups, including liquid-, solid- and membrane-based techniques. The principal of different microextraction methods that are located in each general group as well as their various extraction modes and the recent developments introduced for them has been presented. Subsequently, a comparison survey has been carried out among different microextraction techniques and finally a future perspective has been predicted based on the existing literature.
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Abstract
Multidimensional gas chromatography (MDGC) methods are high-resolution volatile chemical separation techniques, and comprise classical heart-cutting MDGC and its more recent incarnation, comprehensive 2D GC. Although available for a long period, MDGC approaches are still not widely practiced in the field of bioanalysis, possibly reflecting the general preference for regular GC versus MDGC approaches. With the recent introduction of ‘-omic’ techniques that emphasize global nontargeted profiling of metabolites within living systems, it is evident that MDGC is gaining momentum as a separation tool, since it offers very high resolution. By untangling metabolites within highly complex biological matrices, and expanding the metabolic coverage, MDGC plays a frontline role in ‘-omics’ based studies. This review highlights state-of-the-art MDGC approaches, and summarizes the recent developments in bioanalytics.
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Piroozi F, Ghasemi E, Qomi M, Rezaee R, Hashemian F. HOLLOW FIBER LIQUID PHASE MICROEXTRACTION COMBINED WITH HIGH PERFORMANCE LIQUID CHROMATOGRAPHY FOR PRECONCENTRATION AND DETERMINATION OF CABERGOLINE IN BIOLOGICAL SAMPLES. J LIQ CHROMATOGR R T 2014. [DOI: 10.1080/10826076.2012.758142] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Forozan Piroozi
- a Department of Medicinal Chemistry , Pharmaceutical Sciences Research Center, Pharmaceutical Sciences Branch, Islamic Azad University , Tehran , Iran
| | - Ensieh Ghasemi
- b Department of Chemistry , Pharmaceutical Sciences Research Center, Pharmaceutical Sciences Branch, Islamic Azad University , Tehran , Iran
| | - Mahnaz Qomi
- a Department of Medicinal Chemistry , Pharmaceutical Sciences Research Center, Pharmaceutical Sciences Branch, Islamic Azad University , Tehran , Iran
| | - Raheme Rezaee
- a Department of Medicinal Chemistry , Pharmaceutical Sciences Research Center, Pharmaceutical Sciences Branch, Islamic Azad University , Tehran , Iran
| | - Farshad Hashemian
- a Department of Medicinal Chemistry , Pharmaceutical Sciences Research Center, Pharmaceutical Sciences Branch, Islamic Azad University , Tehran , Iran
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Analysis of Salvinorin A in urine using microextraction in packed syringe and GC-MS/MS. Bioanalysis 2013; 5:661-8. [PMID: 23484784 DOI: 10.4155/bio.13.18] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND The aim of this work was to develop and validate a method for the determination of Salvinorin A in human urine using microextraction by packed sorbent (MEPS) and GC-MS/MS. RESULTS The technique uses a sample volume as low as 0.2 ml, and the analyte was extracted using a C18 sorbent. The method showed to be linear between 20 and 1000 ng/ml and presented a LOD of 5 ng/ml. Intra- and inter-day precision and accuracy were acceptable. Absolute recoveries ranged from 71 to 80%. CONCLUSION GC-MS/MS with MEPS demonstrated to be a fast and simple procedure for the quantification of Salvinorin A in urine. This is the first time that GC-MS/MS with MEPS was used for the determination of this compound in biological fluids. Furthermore, the device could be reused for up to 80 extractions, which accounted for a lower cost of analysis.
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Zawilska JB, Wojcieszak J. Salvia divinorum: from Mazatec medicinal and hallucinogenic plant to emerging recreational drug. Hum Psychopharmacol 2013; 28:403-12. [PMID: 23794315 DOI: 10.1002/hup.2304] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2012] [Accepted: 02/19/2013] [Indexed: 11/10/2022]
Abstract
Salvia divinorum is a sage endemic to a small region of Mexico and has been traditionally used by the Mazatec Indians for divination and spiritual healing. Recently, it has gained increased popularity as a recreational drug, used by adolescents and young adults as an alternative to marijuana and LSD. Salvinorin A, the major active ingredient of the plant, is considered to be the most potent known hallucinogen of natural origin. This review surveys the current state of knowledge on the neurochemical, pharmacokinetic, and pharmacological properties of salvinorin A, the trends and motivation behind S. divinorum use, and the health problems among users of the plant's products. S. divinorum induces intense, but short-lived, psychedelic-like changes in mood and perception, with concomitant hallucinations and disorientation. Many websites have misinterpreted the limited existing research-based information on the side effects of salvia as evidence for its safety. However, data accumulated over the last few years indicate that potential health risks are associated with the use of S. divinorum, especially by teenagers, users of other substances of abuse, and individuals with underlying psychotic disturbances. Taken together, the data presented in this review point to the need for further basic and clinical studies to create a basis for the development of well-addressed prevention and treatment strategies.
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Affiliation(s)
- Jolanta B Zawilska
- Department of Pharmacodynamics, Medical University of Lodz, Lodz, Poland
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Margalho C, Gallardo E, Castanheira A, Vieira DN, López-Rivadulla M, Real FC. A validated procedure for detection and quantitation of salvinorin a in pericardial fluid, vitreous humor, whole blood and plasma using solid phase extraction and gas chromatography-mass spectrometry. J Chromatogr A 2013; 1304:203-10. [PMID: 23871557 DOI: 10.1016/j.chroma.2013.07.031] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Revised: 06/11/2013] [Accepted: 07/08/2013] [Indexed: 10/26/2022]
Abstract
The use of vitreous humor and pericardial fluid as alternative matrices to blood and plasma in the field of forensic toxicology is described to quantitate low levels of Salvinorin A using ethion as internal standard. The method was optimized and fully validated using international accepted guidelines. The developed methodology utilizes a solid phase extraction procedure coupled to gas chromatography mass spectrometry operated in the selected ion monitoring mode. The method was linear in the range of 5.0-100ng/mL with determination coefficients higher than 0.99 in 100μL of vitreous humor and in 250μL of each matrix pericardial fluid, whole blood and plasma. The limits of detection and quantitation were experimentally determined as 5.0ng/mL, intra-day precision, intermediate precision and accuracy were in conformity with the criteria normally accepted in bioanalytical method validation. The sample cleanup step presented mean efficiencies between 80 and 106% in the different biological specimens analyzed. According to the low volumes of samples used, and the low limits achieved using a single quadrupole mass spectrometer, which is available in most laboratories, we can conclude that the validated methodology is sensitive and simple and is suitable for the application in forensic toxicology laboratories for the routine analysis of Salvinorin A in both conventional and unconventional biological samples.
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Affiliation(s)
- Cláudia Margalho
- National Institute of Legal Medicine and Forensic Sciences (INMLCF, I.P.) - Centre Branch, Coimbra, Portugal.
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Seeley JV, Seeley SK. Multidimensional Gas Chromatography: Fundamental Advances and New Applications. Anal Chem 2012; 85:557-78. [DOI: 10.1021/ac303195u] [Citation(s) in RCA: 183] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- John V. Seeley
- Oakland University, Department of Chemistry, Rochester, Michigan, 48309
| | - Stacy K. Seeley
- Kettering University, Department of Chemistry and Biochemistry, 1700 University Avenue,
Flint, Michigan, 48504
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Abstract
The last two decades have provided analysts with more sensitive technology, enabling scientists from all analytical fields to see what they were not able to see just a few years ago. This increased sensitivity has allowed drug detection at very low concentrations and testing in unconventional samples (e.g., hair, oral fluid and sweat), where despite having low analyte concentrations has also led to a reduction in sample size. Along with this reduction, and as a result of the use of excessive amounts of potentially toxic organic solvents (with the subsequent environmental pollution and costs associated with their proper disposal), there has been a growing tendency to use miniaturized sampling techniques. Those sampling procedures allow reducing organic solvent consumption to a minimum and at the same time provide a rapid, simple and cost-effective approach. In addition, it is possible to get at least some degree of automation when using these techniques, which will enhance sample throughput. Those miniaturized sample preparation techniques may be roughly categorized in solid-phase and liquid-phase microextraction, depending on the nature of the analyte. This paper reviews recently published literature on the use of microextraction sampling procedures, with a special focus on the field of forensic toxicology.
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Weusten JJAM, Derks EPPA, Mommers JHM, van der Wal S. Alignment and clustering strategies for GC×GC-MS features using a cylindrical mapping. Anal Chim Acta 2012; 726:9-21. [PMID: 22541008 DOI: 10.1016/j.aca.2012.03.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2012] [Revised: 02/28/2012] [Accepted: 03/05/2012] [Indexed: 01/20/2023]
Abstract
Comprehensive two-dimensional gas chromatography coupled to mass spectrometry is a powerful tool to analyze complex samples. For application of the technique in studies like biomarker discovery in which large sets of complex samples have to be analyzed, extensive preprocessing is needed to align the data obtained in several injections (analyses). We developed new alignment and clustering algorithms for this type of data. New in the current procedures is the consistent way in which the phenomenon referred to as wrap-around is treated. The data analysis problems associated with this phenomenon are solved by treating the 2D display as the surface of a three-dimensional cylinder. Based on this transformation we developed a new similarity metric for features as a function of both the cylindrical distance (reflecting similarity in chromatographic behavior) and of the mass spectral correlation (reflecting similarity in chemical structure). The concepts are used in warping and clustering, and include a protection against greedy warping. The methods were applied - for the purpose of an example - to the analysis of 11 replicates of a human urine sample concentrated by solid phase extraction. It is shown that the alignment is well protected against greedy warping which is important with respect to analytical qualities as robustness and repeatability. It is also demonstrated that chemically similar features are clustered together. The paper is organized as follows. First a brief introduction is provided addressing the background of the GC×GC-MS data structure followed by a theoretical section with a conceptual description of the procedures and details of the algorithms. Finally an example is given in the experimental section, illustrating the application of the procedures.
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Affiliation(s)
- Jos J A M Weusten
- DSM Resolve, Dept. Process Analysis & Statistics, Geleen, The Netherlands.
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