Table 2.

Paper-based method vs. the batch fluorescence method.

Sample	QN Found (mg L−1) a
	This Method	Fluorescence Batch Method	(%) Relative Error
1	38.7 ± 1.3	37.0	+4.6
2	2.1 ± 0.2	2.6	−19.2
3	55.5 ± 1.6	56.8	+2.3
4	48.0 ± 6.1	44.6	+7.6
5	70.5 ± 1.9	75.1	−6.1
6	56.0 ± 2.0	57.5	+2.6
7	40.3 ± 1.1	41.1	−1.9
8	50.1 ± 1.2	43.8	+14.4
9	44.5 ± 1.3	42.5	+4.7
10	41.1 ± 2.8	44.4	−7.4

^a Mean of three measurements.