Extractive Spectrophotometric Method for Determination of Molybdenum in Steels and Environmental Samples

Table 1

Effect of various parameters on the absorbance of Mo(V)-CHHB complex.

H2SO4^a/M	0.01	0.05	0.2	0.5–2.2	3.0
Absorbance	0.390	0.520	0.555	0.586	0.574
H2SO4^b/M	0.01	0.05	0.2–2.0	2.5	3.0
Absorbance	0.322	0.510	0.586	0.563	0.535
5% ascorbic acidc/M	0.0	0.1	0.15–2.5	3.0	4.0
Absorbance	0.533	0.575	0.586	0.561	0.547
0.1% CHHBd/mL	0.1	0.3	0.5	0.6–1.5	2.0
Absorbance	0.090	0.320	0.410	0.586	0.565
Equilibration timee/s	3	5	10–180	250	300
Absorbance	0.290	0.455	0.586	0.560	0.532

aConditions: Mo = 1 mL of 1.0423 × 10^-4M solution; 5% ascorbic acid = 2 mL; CHHB [0.1% (w/v) in ethanol] = 1 mL; aqueous volume = organic solvent volume = 10 mL; organic solvent = toluene; equilibration time = 30 s; number of extractions = 1.
bConditions: 10 M H₂SO₄ = 1 mL; other conditions are the same as in (a) except for H₂SO₄ content before extraction.
cConditions: other conditions are same as in (a) excepting variation in ascorbic acid content.
dConditions: 5% (w/v) ascorbic acid = 2 mL; other conditions are the same as in (a) except for CHHB content; absorbance is measured against the reagent blank.
eConditions: CHHB [0.1% (w/v) in ethanol] = 1 mL; other conditions are the same as in (a) except for equilibration time.