Approaches to the solid-phase extraction of equine urine

Three approaches to the solid-phase extraction of horse urine are reviewed. Simple reversed-phase SPE may be coupled with a chromatographic technique that provides a second stage of separation in the presence of a high matrix background. Pre-extraction of the urine or hydrolysed urine allows the elimination of salts and other matrix related interferences prior to the primary extraction. Serial processing of urine, hydrolysed urine or pre-extracted samples through specialty sorbents allow speciation of a single sample into many different classes suitable for Systematic Toxicological Analysis analysis by GC-MS or LC-MS. The multi-eluate approach allows significant reduction of the matrix background when compared with parallel SPE of a sample.