Comparison of Three Sample Preparation Procedures for the Quantification of L-Arginine, Asymmetric Dimethylarginine, and Symmetric Dimethylarginine in Human Plasma Using HPLC-FLD

Table 3

Stability data for human plasma prepared by procedure (A) and a calibration standard at ULOQ as well as long-term data at −80°C for human plasma and at −20°C for a calibration stock solution. The data are calculated as average of three determinations.

	4°C				−80°C	−20°C
	Prepared human plasma		Calibration standard		Human plasma	Calibration stock solution
	24 h	48 h	24 h	48 h	6 months
L-arginine	96.1%	95.4%	91.1%	87.5%	95.3%	91.5%
ADMA	92.8%	93,5%	91.8%	89.6%	95.0%	103%