Matrix-elimination with steam distillation for determination of short-chain fatty acids in hypersaline waters from pre-salt layer by ion-exclusion chromatography.
A method for determination of formic, acetic, propionic and butyric acids in hypersaline waters by ion-exclusion chromatography (IEC), using steam distillation to eliminate matrix-interference, was developed. The steam distillation variables such as type of solution to collect the distillate, distillation time and volume of the 50% v/v H₂SO₄ solution were optimized. The effect of the addition of NaCl different concentrations to the calibration standards on the carboxylic acid recovery was also investigated. Detection limits of 0.2, 0.5, 0.3 and 1.5 mg L⁻¹ were obtained for formic, acetic, propionic and butyric acids, respectively. Produced waters from petroleum reservoirs in the Brazilian pre-salt layer containing about 19% m/v of NaCl were analyzed. Good recoveries (99-108%) were obtained for all acids in spiked produced water samples.
Coordenação de Análises Minerais, Centro de Tecnologia Mineral-CETEM, Av. Pedro Calmon 900, Cidade Universitária, CEP 21941-908, Rio de Janeiro, RJ, Brazil.
Fernanda N
FN
Ferreira
Manuel C
MC
Carneiro
Delmo S
DS
Vaitsman
Fernanda V M
FV
Pontes
Maria Inês C
MI
Monteiro
Lílian Irene D da
LI
Silva
Arnaldo Alcover
AA
Neto
D001938:Brazil; D002852:Chromatography, Ion Exchange / Q000379:methods*; D057168:Distillation / Q000379:methods*; D005232:Fatty Acids, Volatile / Q000032:analysis / Q000302:isolation & purification*; D007477:Ions / Q000737:chemistry; D057230:Limit of Detection; D054712:Salinity; D012965:Sodium Chloride / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
D005232:Fatty Acids, Volatile; D007477:Ions; D014867:Water; D012965:Sodium Chloride