APPLICABILITY OF VARIOUS BRANDS OF MIXED-PHASE EXTRACTION COLUMNS FOROPIATE EXTRACTION FROM BLOOD AND SERUM

Four commercially available types of mixed-phase solid-phase extractio n (SPE) columns (Bond Elut Certify, Isolute Confirm HCX, Chromabond Dr ug and Bakerbond Narc-2) were examined in order to compare the extract ion efficiencies and chromatographic purity of extracts. The absolute recovery of morphine, 6-monoacetylmorphine and codeine was examined in blood and serum (ten samples each at two concentration levels), using SPE columns of the same batch. GC-MS (ion trap) and HPLC with amperom etric detection were used for quantitation. A distinct variability in extraction recovery was observed among the same batches of all brands of SPE columns. All extracts were chromatographically pure and no inte rfering peaks were observed, neither in GC-MS nor in HPLC examinations , but in some extracts large peaks of plasticizers were identified. Th e measurements of how velocities of the same samples of blood or serum through the SPE columns of the same batch showed very large variabili ty of random character. The morphometric analysis of particles was per formed for two batches of each sort of SPE columns by means of an imag e analysing system. Symmetrical distribution of particle size was obse rved only in Chromabond MN Drug packing, while in other cartridges lar ge fractions of fine particles and nonhomogenous distribution were fou nd. Only in one case the morphometric findings were pretty concordant with the data available from the manufacturer; in two cases, observed data varied considerably from that expected, and in one case no inform ation was available at all. The study showed generally that there was room for improvement in the quality of mixed-phase SPE columns.