Quantification of gadodiamide as Gd in serum, peritoneal dialysate and faeces by inductively coupled plasma atomic emission spectroscopy and comparative analysis by high-performance liquid chromatography

An inductively coupled plasma atomic emission spectroscopy (ICP-AES) method for determination of gadodiamide as Gd in serum, peritoneal dialysate and faeces was developed. The within-day and between-day precision for determin ation of Cd in serum and peritoneal dialysate were 0.60-2.9 and 1.8-4.4%, r espectively, and the accuracy was 98.0-99.3%. The quantification limits in serum and peritoneal dialysate were 6.5 and 1.6 mu M Gd, respectively. The within-day and between-day precision determination of gadolinium in faeces were 1.0-5.3 and 2.2-7.9%, respectively, and the accuracy was 104-116%. The quantification limit was 11 nmol Gd/g dry weight. For the high-performance liquid chromatography (HPLC) method, the within-day precision in determina tion of gadodiamide in peritoneal dialysate was 1.2% and the accuracy was 1 03%. The quantification limit was 0.9 mu M Gd. Comparative analysis of gado diamide in serum and peritoneal dialysate from severely impaired renal pati ents by ICP-AES and HPLC revealed no metabolism of chelator or transmetalla tion of gadolinium, even in samples obtained as long as 7 days after dosing . Furthermore, the ICP-AES determination of Cd in faeces allows for the det ermination of faeces content of Gd corresponding to less than 0.1% of a cli nical dosage of a Gd-based contrast medium. (C) 2000 Elsevier Science Ltd. All rights reserved.