Table 8 Comparison of various methods for determination of CAA with published results in the literature
Method | Conditions | Result | Reference |
|---|---|---|---|
UV-spectrophotometer | Diazosulfanic acid + sodium hydroxide solution, read at 490 nm | Read against reagent blank and test solution | [20] |
Calorimetric method | Diazosulfanic acid + sodium carbonate solution | Read against reagent blank and test solution | [22] |
Gas chromatography method | Column, 1 m (3–4) mm; sorbent, 10% poly(ethylene glycol) sebacate on Polysorb I; temperature regime: column thermostat, 100 °C; DTP detector, 150 °C; evaporator, 300 °C; detector current, 190 mA; carrier gas (helium) flow rate, 30 ml/min; sample volume 0.4 μl | Recovery ranges from 97.95 to 101.1% | [21] |
High-performance liquid chromatography | C18 column(250 mm × 4.6 mm, 4 μm), mixture of 0.02 mol/L potassium dihydrogen phosphate and methanol (volume ratio of 90:10) with pH 2.0, UV detection at 228 nm | Linear correlation of the method was 0.9999, the standard deviation was 0.20 and the average recovery was 99.78%. | [24] |
Ion chromatography | The column was a METROSEP A SUPP 5, 6.1006.530, (250 mm × 4.0 mm) 5 μm particles of Polyvinyl alcohol with quaternary ammonium groups. The mobile phase has consists of 504 mg of sodium bicarbonate and 53 mg of sodium carbonate in 1000 mL of water, conductivity detector | LOD and LOQ 33 μg/g and 101 μg/g respectively, average recovery 98.6% to 100.1% and linearity 0.999 | Present work |