Near Infrared Raman Spectroscopy (NIRS): A technique for doping control

Abstract

This paper reports the application of near-infrared Raman spectroscopy to detect ephedrine in biological medium. At present time, the doping control for ephedrine in athletes uses the urinalysis by the gas chromatography/mass spectrometry, with main disadvantage the need of collecting urine and the time delay to obtain results. This work aims to develop a noninvasive technique that will allow to evaluate the concentration of the ephedrine in a real time diagnosis. A Raman system composed by a Ti:Saphire laser pumped by an Argon laser was used, operating at the wavelength of 785 nm, with a laser power of 70 mW at sample position. Raman scattered photons were collected by a f/l.8 spectrometer and a N2-cooled CCD detector. Ephedrine Raman peaks at 1002 and 1603 cm−1were studied, opening possibility for the identification and quantification of ephedrine. Raman spectra of ephedrine with different concentrations in human urine were taken, and the intensity of the ephedrine peak at 1002 cm−1was measured as a function of its concentration. It was also studied the Raman spectrum of an urine sample from a Wistar rat, after a subcutaneous inoculation of an ephedrine solution in physiologic serum, at the concentration of 5 mg/ml. It was found that Raman spectroscopy could detect ephedrine in urine at concentrations lower than the doping limit legally permitted by the International Olympic Committee.

Correlating the amount of urea, creatinine, and glucose in urine from patients with diabetes mellitus and hypertension with the risk of developing renal lesions by means of Raman spectroscopy and principal component analysis

“…[11][12][13][14] Using dispersive or FourierTransform Raman techniques in the near-infrared spectrum, there is no need for additional chemical steps for analysis (separation, dilution, or mixture of other reagents) and may prove superior to current methods of testing urine, 11,12 nondestructively. Biochemical assays based on Raman spectroscopy could be used for testing body fluids such as blood, blood components, and metabolites in the serum for doping control, 15 detecting antibodies in cat's serum, 16 and even monitoring heparin levels in blood during surgeries. 17 Optical techniques may become a future alternative or even replace existing laboratory methods.…”

Detecting alterations of glucose and lipid components in human serum by near-infrared Raman spectroscopy

“…Since this optical technique does not need sample preparation, a small volume of sample is required. In addition, analysis time is short, allowing dynamic monitoring at a low cost (Carey, 1982;Gremlich and Yan, 2001;Guimarães et al, 2006;Hanlon et al, 2000;Movasaghi et al, 2007;Twardowski and Anzenbacher, 1994).…”

Rapid analysis of pharmaceuticals and excreted xenobiotic and endogenous metabolites with atmospheric pressure infrared MALDI mass spectrometry

“…Mass spectrometry is a well established tool for the analysis of xenobiotic and endogenous metabolites (Dettmer et al 2007;Glassbrook et al 2000;Nicholson et al 2002;Siuzdak 1994). Many other non-mass spectrometric techniques, such as infrared spectrometry (Blanco et al 1998;Guimarães et al 2006;MacDonald and Prebble 1993), Raman spectroscopy (Strachan et al 2007), terahertz imaging (Kawase et al 2003), fluorescence spectroscopy (Moreira et al 2005) and nuclear magnetic resonance (Balchin et al 2005;Maher et al 2007;Popchapsky and Popchapsky 2001), provide useful and complementary information on their chemical composition. Mass spectrometry gives unique insights into metabolism due to its high sensitivity and the ability to selectively identify these molecules through fragmentation studies.…”