| Popis: |
Various effects on extraction efficiencies when using a micro‐extraction technique to extract benzene, toluene, ethylbenzene, and o‐xylene from water into pentane were studied. The effects of sample to solvent ratio (20:1 and 100:1), salting out with sodium sulfate, and the presence of other organic substances in the matrix were all evaluated. Observed microextraction efficiencies were in good agreement with values calculated from published partition coefficients. For benzene, which was the least well extracted, saturating the aqueous sample with sodium sulfate increased recoveries significantly. When a water‐soluble organic (acetonitrile) was also present at high levels, the recoveries were generally decreased; however, this effect was eliminated when the aqueous phase was saturated with sodium sulfate. |
