title: Systematic analysis of glycerol: colourimetric screening and gas chromatography-mass spectrometric confirmation.
abstract: 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.
authors.affiliation: Universidade Federal do Rio de Janeiro, Instituto de Química, LBCD - LADETEC, Avenida Athos da Silveira Ramos, 149, 21941-909, Rio de Janeiro, Brazil.
authors.forename: Vinícius F
authors.initials: VF
authors.lastname: Sardela
authors.affiliation: Universidade Federal do Rio de Janeiro, Instituto de Química, LBCD - LADETEC, Avenida Athos da Silveira Ramos, 149, 21941-909, Rio de Janeiro, Brazil.
authors.forename: Fernanda B
authors.initials: FB
authors.lastname: Scalco
authors.affiliation: Universidade Federal do Rio de Janeiro, Instituto de Química, LBCD - LADETEC, Avenida Athos da Silveira Ramos, 149, 21941-909, Rio de Janeiro, Brazil.
authors.forename: Karina M
authors.initials: KM
authors.lastname: Cavalcante
authors.affiliation: Universidade Federal do Rio de Janeiro, Instituto de Química, LBCD - LADETEC, Avenida Athos da Silveira Ramos, 149, 21941-909, Rio de Janeiro, Brazil.
authors.forename: Ruth E
authors.initials: RE
authors.lastname: Simoni
authors.affiliation: Universidade Federal do Rio de Janeiro, Instituto de Química, LBCD - LADETEC, Avenida Athos da Silveira Ramos, 149, 21941-909, Rio de Janeiro, Brazil.
authors.forename: Deyvison R
authors.initials: DR
authors.lastname: Silva
authors.affiliation: Universidade Federal do Rio de Janeiro, Instituto de Química, LBCD - LADETEC, Avenida Athos da Silveira Ramos, 149, 21941-909, Rio de Janeiro, Brazil.
authors.forename: Henrique Marcelo G
authors.initials: HM
authors.lastname: Pereira
authors.affiliation: Universidade Federal do Rio de Janeiro, Instituto de Química, LBCD - LADETEC, Avenida Athos da Silveira Ramos, 149, 21941-909, Rio de Janeiro, Brazil.
authors.forename: Maria Lúcia L Costa
authors.initials: ML
authors.lastname: de Oliveira
authors.affiliation: Universidade Federal do Rio de Janeiro, Instituto de Química, LBCD - LADETEC, Avenida Athos da Silveira Ramos, 149, 21941-909, Rio de Janeiro, Brazil.
authors.forename: Francisco R
authors.initials: FR
authors.lastname: Aquino Neto
mesh_terms: D056352:Athletes; D003124:Colorimetry / Q000379:methods*; D004300:Doping in Sports; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D005990:Glycerol / Q000652:urine*; D006801:Humans; D057230:Limit of Detection; D015813:Substance Abuse Detection / Q000379:methods*
chemical_list: D005990:Glycerol
keywords: anti-doping; colourimetric screening; gas chromatography-mass spectrometry; glycerol; urine