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

Table 1

Determined average concentrations of L-arginine and ADMA in human plasma ±SD (n = 3) and average recovery ±SD (n = 3) at three concentration levels obtained with sample preparation procedure (A). Recovery values in % given as mean ± SD (n = 3) obtained for procedure (B) and procedure (C) are shown for comparison.

	Human plasma, mean ± SD (µM)	Procedure A			Procedure B	Procedure C
		Added (µM)	Measured, mean ± SD (µM)	Recovered, mean ± SD (%)	Recovered, mean ± SD (%)	Recovered, mean ± SD (%)
L-arginine	65.3 ± 2.09	20	94.3 ± 10.1	113 ± 8.21	—	—
		40	115 ± 3.20	109 ± 2.78	68.4 ± 5.50	118 ± 3.62
		60	138 ± 8.67	110 ± 6.92	—	—
ADMA	0.40 ± 0.013	0.1	0.47 ± 0.030	91.5 ± 3.03	—	—
		0.2	0.59 ± 0.070	98.0 ± 7.07	73.5 ± 4.22	94.7 ± 8.46
		0.3	0.70 ± 0.032	98.9 ± 4.55	—	—