OPTIMIZACIóN DEL MéTODO DE MICROEXTRACCIóN EN FASE SóLIDA ACOPLADA A CROMATOGRAFíA GASEOSA PARA ANáLISIS DE METANOL EN AGUA

the technique head space-solid phase micro extraction with gaseous chromatography by using flame ionization detector (hs-spme/gc-fid) for analysis of methanol in water was optimized using different microfibers, a polyacrylate fiber and a polydimethylsiloxane fiber and a rtx-5 column. the evaluated variables were time of absorption of the pollutant on the fiber, free volume in the vial (free space), time and temperature of desorption as well as effect of agitation and presence of salt in the system. according to the results, the optimal absorption time is 15 minutes, the optimal volume of sample is 5 ml. a close relationship between the temperature of desorption and the chromatographic peak area was found, and a correlation r2 = 0.99965 was obtained for the calibration curve in a range between 0 and 50%, considering the origin, with a detection limit of 0.01% and a quantification limit of 0.04%.