Table 3.

Inter-day assay precision and accuracy of the HPLC method for the determination of NAG^*

Nominal concentration (µg/ml)	Calculated concentration (µg/ml)	Precision RSD (%)	Accuracy error
1	0.935	6.46	2.41
2	2.009	3.53	-0.454
4	4.07	2.94	-1.925
6	5.93	1.59	1.215
8	8.17	1.01	-2.146
10	9.88	0.42	1.188

^*Validation study, n=5 days, five replicates per day