Consequences of the formation of 3,4-dimethyl-5-phenyl-1,3-oxazolidine on the analysis of ephedrines in urine by gas chromatography and a new method for confirmation as N-trifluoroacetyl-O-t-butyldimethylsilyl ether derivatives

Sardela, Vinícius Figueiredo; Sardela, P.D.O.; Pereira, Henrique Marcelo Gualberto; Neto, Francisco Radler de Aquino

doi:10.1016/j.chroma.2010.12.120

Cited by 14 publications

(7 citation statements)

References 26 publications

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“…Despite the constantly increasing importance of LC‐(MS/)MS concerning the analysis of stimulants in doping control samples GC‐MS(/NPD) is still a commonly employed strategy offering several advantages over LC‐(MS/)MS‐based methods. However, the high temperatures of most GC injectors might induce the formation of artefacts as recently reported for ephedrine and its analogues which could cause misidentifications . The adduct of β‐aminoalcohols (such as ephedrine and pseudoephedrine) and formaldehyde was shown to result in oxazolidine derivatives, leading to an over‐ or underestimation of the relevant stimulants.…”

Section: Stimulantsmentioning

confidence: 97%

Annual banned‐substance review: analytical approaches in human sports drug testing

Thevis

Kuuranne

Geyer

et al. 2012

Drug Testing and Analysis

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a International anti-doping efforts are harmonized and regulated under the umbrella of the World Anti-Doping Code and the corresponding Prohibited List, issued annually by the World Anti-Doping Agency (WADA). The necessity for a frequent and timely update of the Prohibited List (as the result of a comprehensive consultation process and subsequent consensual agreement by expert panels regarding substances and methods of performance manipulation in sports) is due to the constantly growing market of emerging therapeutics and thus new options for cheating athletes to illicitly enhance performance. In addition, 'tailor-made' substances arguably designed to undermine sports drug testing procedures are considered and the potential of established drugs to represent a doping substance is revisited in light of recently generated information. The purpose of the annual banned substance review is to support doping controls by reporting emerging and advancing methods dedicated to the detection of known and recently outlawed substances. This review surveys new and/or enhanced procedures and techniques of doping analysis together with information relevant to doping controls that has been published in the literature between October

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Section: Stimulantsmentioning

confidence: 97%

Annual banned‐substance review: analytical approaches in human sports drug testing

Thevis

Kuuranne

Geyer

et al. 2012

Drug Testing and Analysis

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“…The confirmation analysis was validated quantitatively in accordance with WADA criteria, [13] following the same parameters validated by Sardela et al [14] Results and discussion…”

Section: Gc-ms Conditions/instrumentationmentioning

confidence: 99%

Systematic analysis of glycerol: colourimetric screening and gas chromatography–mass spectrometric confirmation

Sardela

Scalco

Cavalcante

et al. 2015

Drug Testing and Analysis

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Glycerol is a naturally occurring polyol in the human body, essential for several metabolic processes. It is widely used in the food, pharmaceutical, and medical industries and in clinical practice as a plasma volume expander (PVE). Athletes, however, may use glycerol to mask the presence of forbidden substances or to enhance performance, inclusively through hyperhydration achieved by glycerol ingestion with added fluid. These practices are considered doping, and are prohibited by the World Anti-Doping Agency (WADA). Therefore, glycerol was introduced in the prohibited list. Doping through glycerol ingestion can readily be identified by detection of elevated glycerol concentrations in urine. In this paper, a protocol for the fast detection of glycerol in urine is proposed. It consists of a previous visual colourimetric screening, followed by a quantitative/qualitative confirmation analysis by mass spectrometry. The screening procedure involves a reaction in which polyhydric alcohols are oxidized by periodate to formic acid and formaldehyde, which is detected by the addition of a fuchsin solution. For the subsequent qualitative/quantitative confirmation analysis, a gas chromatography-mass spectrometry based approach with a non-deuterated internal standard and a drying step of only 10 min is proposed. The linear correlation was demonstrated within WADA´s threshold range. The calculated RSD were 2.1% for within-day precision and 2.8% for between-day precision. The uncertainty estimation was calculated, and a value of 2.7% was obtained. The procedure may also be used for the analysis of other polyols in urine, as for example the PVE mannitol.

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“…Evaluating the graphic's surface for the volume against the Tinj (Figure 4a), it was revealed that at 3 µL Vinj, the response remains the same after 250 °C; thus, at higher temperatures, the results were practically the same. Given the possibility of ephedrine degradation, 9 the final Tinj of 250 °C was considered the best.…”

Section: Injection Doehlert Matrix Optimizationmentioning

confidence: 99%

“…[14][15][16] All other methods described, including the GC-based ones, require sample pretreatment such as liquid-liquid extraction, solid-phase extraction and/or filtration, which is time-consuming and reduces the sample throughput . [8][9][10]17 The application of GC analysis to quantify ephedrines was first developed in 1977 by Lin et al 18 They used a specific electron-capture assay after a liquid-liquid extraction with benzene and trifluoroacetic acid (TFA) derivatives to detect pseudoephedrine and norpseudoephedrine. 18 Subsequently, the GC method to determine ephedrine was modified to reduce the toxicity of sample preparation and improve the sensitivity using toluene as the extraction solvent and trifluoroacetic anhydride (TFAA).…”

Section: Introductionmentioning

confidence: 99%

“…Many methods have been developed to quantify ephedrines in urine, including the gas chromatography nitrogen phosphorous detector (GC-NPD), 8 GC mass spectrometry (GC-MS), 9 ion mobility MS (IM-MS) 10 and liquid chromatography MS in tandem (LC-MS/MS). 11 Among them, LC-MS/MS is the most frequently used method, enabling the direct injection of dilute urine into the chromatographic system.…”

Section: Introductionmentioning

confidence: 99%

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Fast Ephedrine Quantification by Gas Chromatography Mass Spectrometry

Carneiro¹,

Silva²,

Cavalcante³

et al. 2018

J. Braz. Chem. Soc.

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Ephedrines are widely used in therapy. Because of their stimulant properties, these substances are relevant in different forensic fields. At present, the state of the art for ephedrines quantification relay based on a liquid chromatography mass spectrometry, mainly because of the dilute-andshoot approach. Notwithstanding, several gas chromatography based methods have already been described, all of them include cleanup steps, with the potential disadvantage of incurring errors and increasing the workload. In this paper, a straightforward method for ephedrine quantification based on gas chromatographic mass spectrometry, without cleanup and based on Doehlert matrix optimization is presented. Only 10 µL of a urine sample is necessary and for N-methyl-N-(trimethylsilyl)trifluoroacetamide/N-methyl-bis-trifluoracetamide derivatives, the intermediate precision was 2.77% for ephedrine, 9.20% for cathine, 8.29% for norephedrine and 4.27% for pseudoephedrine. The limit of detection was 20 ng mL -1 for ephedrine, 30 ng mL -1 for cathine and 40 ng mL -1 for norephedrine and pseudoephedrine.

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Consequences of the formation of 3,4-dimethyl-5-phenyl-1,3-oxazolidine on the analysis of ephedrines in urine by gas chromatography and a new method for confirmation as N-trifluoroacetyl-O-t-butyldimethylsilyl ether derivatives

Cited by 14 publications

References 26 publications

Annual banned‐substance review: analytical approaches in human sports drug testing

Annual banned‐substance review: analytical approaches in human sports drug testing

Systematic analysis of glycerol: colourimetric screening and gas chromatography–mass spectrometric confirmation

Fast Ephedrine Quantification by Gas Chromatography Mass Spectrometry

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