An Environmentally Friendly Compact Microfluidic Hydrodynamic Sequential Injection System Using Curcuma putii Maknoi & Jenjitt. Extract as a Natural Reagent for Colorimetric Determination of Total Iron in Water Samples

Table 3

Study on aspiration sequences.

No	Carrier solution	Sequence^a	Calibration graph equation	r^2
1	deionized water	R/S/R	y = 0.0301x + 0.1368	0.9964
2	Acetate buffer	R/S/R	y = 0.1586x − 0.0109	0.9992
3	Natural reagent	R/S/R	y = 0.3253x − 0.2195	0.9746
4	Standard/sample solution	S/R/S	y = 0.1094x + 0.1678	0.9931

^aR and S represent natural reagent and standard/sample, respectively.