Table 2.

A comparison of the two different methods used to determine indigo carmine concentration in the food dye sample.

UV/Vis Spectrophotometric Method
A = n + kC	n	Error n (Sn)	k(slope) (Mol−1 dm3)	Error k (Sk) (Mol−1 dm3)
A = 1.000 + 9000 × C	1.000	0.005	9000	100
	LOD = 3.3 × Sn/k		LOQ = 10 × Sn/k
	1.8 × 10−6 mol dm−3		5.7 × 10−6 mol dm−3
Briggs–Rauscher oscillatory method
τinh = n + kC	n(s)	error n (Sn) (s)	k(slope) (mol−1 dm3 s)	error k (Sk) (mol−1 dm3 s)
τinh = 3 + 4 × 108 × Cind	3	2	4 × 108	1 × 107
	LOD = 3.3 × Sn/k		LOQ = 10 × Sn/k
	1.65 × 10−8 mol dm−3		5 × 10−8 mol dm−3