International Journal of Analytical Chemistry / 2012 / Article / Tab 5 / Research Article
Spectrophotometric Determination of Iron(II) and Cobalt(II) by Direct, Derivative, and Simultaneous Methods Using 2-Hydroxy-1-Naphthaldehyde-p-Hydroxybenzoichydrazone Table 5 Analytical characteristics of [Fe(II)-HNAHBH].
Parameter Direct method First derivative Second derivative Third derivative 405 nm 427 nm 421 nm 435 nm 415 nm 426 nm Beer’s law range (μ g mL−1 ) 0.055–1.373 0.027–1.376 0.027–1.376 0.027–1.376 0.027–1.376 0.027–1.376 Molar absorptivity, (L mol−1 cm−1 )
— — — Sandell’s sensitivity, (μ g cm−2 ) 0.0012 — — — Angular coefficient (m) 0.974 0.072 0.006 0.093 0.002 0.085 Y-intercept (b) 0.0047 −0.0045
Correlation coefficient 0.9997 0.9999 0.9999 0.9999 0.9999 0.9999 RSD (%) 2.19 0.85 0.76 0.89 1.31 1 Detection limit (μ g mL−1 ) 0.065 0.1 0.022 0.0268 0.036 0.304 Determination limit, (μ g mL−1 ) 0.197 0.3 0.068 0.8 0.11 0.914 Composition (M : L) 2 : 3 — — — Stability constant
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