Uniflex Co., Ltd.

To determine blood urea accurately in uremia patients, a simple anal. procedure combining a solid phase extraction (SPE) and high performance liquid chromatog. (HPLC) was studied.SPE was performed using Bond Elute SCX (resin weight, 500 mg; resin volume, 2.8 mL) which was conditioned with 3 mL of MeOH followed by 3 mL of water and eluted with 4 mL of 5% phosphate solutionFor HPLC, MCI gel CK08S (4.6 × 150 mm) was eluted with 1 mM HCl at a flow rate of 1 mL/min and column temperature at 35° with detection at 200 nm.By comparing ultrafiltrated blood urea and native blood urea, the blood urea from the HPLC chromatogram was found to be completely free of blood admixtures and almost free of blood protein.We concluded that the current clin. method of blood urea determination which uses an ammonia selective electrode could be replaced by our method which is more selective and provides more accurate and reliable data for diagnosis.