Bioequivalence and Bioavailability Forum

Neither is 'better' than the other, they're two different extraction methods that each have their own upsides and downsides.

PPT – Protein Precipitation, where an excess of some reagent (often organic solvent such as acetonitrile) is added that causes the proteins in the sample to denature and precipitate out, where they can be filtered or spun down to give the rest of the sample. Pros; Cheap, Quick and Simple, Cons; Still gives a fairly dirty sample, can result in ion suppression.

SPE – Solid Phase Extraction, where the sample is added to a solid extraction column (such as C18 silica) and then unwanted compounds washed away, before the wanted analytes are eluted, then usualy dried down, reconstituted in a suitable injection solvent. Pros; Gives cleaner sample, Cons; Takes longer, can loose material during dry down step, method dev takes longer, more expensive

Check out;
Gilar, M., Bouvier, E. S. P., & Compton, B. J. 2001, "Advances in sample preparation in electromigration, chromatographic and mass spectrometric separation methods", Journal of Chromatography A, vol. 909, no. 2, pp. 111-135.

McDowall, R. D. 1989, "Sample preparation for biomedical analysis", Journal of Chromatography B: Biomedical Sciences and Applications, vol. 492, pp. 3-58.

Xu, R. N., Fan, L., Rieser, M. J., & El Shourbagy, T. A. 2007, "Recent advances in high-throughput quantitative bioanalysis by LC-MS/MS", Journal of Pharmaceutical and Biomedical Analysis, vol. 44, no. 2, pp. 342-355.