COMPARAÇÃO ENTRE A CROMATOGRAFIA GASOSA E O TESTE ELISA NA QUANTIFICAÇÃO DE CAFEÍNA NO PLASMA EQÜINO.

Being less expensive and more practical, ELISA test has been used to quantify several drugs in antidoping testing protocols. Caffeine is a central nervous system stimulant and it gains importance in the horse industry because it is considered a prohibited substance by many regulatory organs of equine sports. The aim of this study was to compare ELISA test and gas chromatography (GC) to quantify caffeine in the plasma of horses. Animals received 2 mg/Kg of caffeine of 50% of the colorimetric reaction of the standard curve (I50), a grater correlation was assessed in the group that had the ratio between 0.68 and 1.43 (r = 0.96). This analysis showed that ELISA test is capable of quantifying plasma caffeine in horses when the ratio between the plasma concentration and the I50 is close to 1. IV. The samples were collected at the times 0h, 0.25h, 0.5h, 1h, 2h, 4h, 6h, 8h, 12h, 24h, 48h and 72h pos-caffeine. Both methods showed maximum concentration at 0.25h. Pearson´s correlation coefficient between the two methods was r = 0.50, meaning poor correlation. The regression’s equation was Y=0.358 + 2.125X. After classifying samples in groups according to the ratio between the concentration measured by the ELISA test and the concentration that causes inhibition