Table 1.

Precision of measurement for sample containing 5 μg SDBS and fluctuations of blank value

No.	Absorbance for sample containing 5 μg SDBS	Determined SDBS content (μg)	Absorbance for blank	Determined SDBS content (μg)
1	0.1775	4.56	0.0422	0.0924
2	0.1744	4.45	0.0406	0.0396
3	0.1735	4.43	0.0417	0.0759
4	0.1779	4.57	0.0419	0.0825
5	0.1756	4.50	0.0415	0.0693
6	0.1736	4.43	0.0426	0.1056
7	0.1715	4.48	0.0427	0.1089
Mean	0.1749	4.49	0.0419	0.0820
SD	0.0023	0.0582	0.0007	0.0238
RSD (%)	1.31	1.30	1.72	29.0