Samples
Optical sensor method (mg L-1) Ponceau-S/TCA method (mg L-1)
1 23.3 ± 3.7 23.6 ± 2.4
2 14.7 ± 4.3 15.1 ± 2.2
3 11.7 ± 3.4 12.0 ± 2.2
4 26.0 ± 2.1 26.3 ± 2.6
5 15.1 ± 2.5 14.6 ± 2.3
6 23.5 ± 2.8 23.3 ± 2.6
7 14.3 ± 3.2 14.6 ± 2.5