Spectrophotometric Determination of Iron(II) and Cobalt(II) by Direct, Derivative, and Simultaneous Methods Using 2-Hydroxy-1-Naphthaldehyde-p-Hydroxybenzoichydrazone

Table 2

Determination of iron in surface soil.

Sample	Source of the sample	Amount of iron (mg Kg^−1) ± SD*
S1	Groundnut cultivation soil; Akuthotapalli, Anantapur	40.98 ± 0.45
S2	Cotton cultivation soil,; Singanamala, Anantapur district,	27.48 ± 0.36
S3	Sweet lemon cultivation soil,; Garladinne, Anantapur distrcct	44.88 ± 0.24
S4	Paddycultivation soil; Garladinne, Anantapur district	20.86 ± 0.37

*Average of five determinations.