A New Spectrophotometric Reagent for Fe(III): 2-(2,3-Dihydroxy-4-oxocyclobut-2-enylidene) Hydrozinecarbothiamide and Its Application in Real Samples

Table 2

Conditions for the spectrophotometric determination of Fe(III).

Wavelength of maximum absorbance (nm)	465
Limit of detection (LOD) (μg·mL^−1)	0.08
Limit of quantification (LOQ) (μg·mL^−1)	0.26
LOD/LOQ	0.3
Linear range (μg·mL^−1)	0.27–33.50
Molar absorptivity (L·mol^−1·cm^−1)	1.95 × 10^3
Optimized pH	~3
Calibration graph slope	0.035
Intercept	0.008
Correlation coefficient (𝑟^2)	0.995
Relative standard deviation (%) (𝑛=10)^a	0.8–1.2%

^aRSD was determined for Fe(III) in the range of 0.3–30 μg·mL⁻¹.