Nwoke, Spectrophotometric Determination of Hydralazine using p-dimethylaminobenzaldehyde
, JICS, 5, 316 (2008).
(6-8,15,16) Strips of Whatman filter paper were impregnated with a solution of reagent consisting of p-dimethylaminobenzaldehyde
, oxalic acid and sodium dodecylbenzene sulfonate dissolved in 70% ethanol.
Ehrlich reagent was prepared as 20 g/L of p-dimethylaminobenzaldehyde
(Sigma-Aldrich) in 250 [micro]L/L glacial acetic acid in concentrated hydrochloric acid (9 mol/L final concentration) and stored for 1 month in a glass bottle.
For the selected benzaldehyde derivative (p-dimethylaminobenzaldehyde), Beer's law is obeyed over the concentration range 5-215 [micro]g [ml.sup.-1] pyruvic acid.
Moreover, p-dimethylaminobenzaldehyde (P-DMAB) reagent was also suggested as spectrophotometric reagent for the analysis of pyruvic acid [33,34].
0.5% w/v stock solution of p-dimethylaminobenzaldehyde (Aldrich, UK) was prepared by dissolving 0.5g in 100 ml distilled water.
Sodium pyruvate in the presence of p-dimethylaminobenzaldehyde (P-DMAB) solution and potassium hydroxide forms a bright yellowish solution due to the typical aldol condensation reaction given in Scheme 1.
Hoseney RC, Finney KF (1964) Spectrophotometric determination of urea, thiourea, and certain of their substitution products with p-dimethylaminobenzaldehyde and diacetyl monoxime.
Schulz H (1975) Using p-dimethylaminobenzaldehyde for extraction and colorimetric determination of urea in soil.
It is performed by mixing 1 mL of urine with 1 mL of p-dimethylaminobenzaldehyde in acid solution (Ehrlich's reagent).
Ehrlich's reagent (2 mL; 1 g of p-dimethylaminobenzaldehyde in 50 mL of 6 mol/L HCl) was added, the bottle was stoppered, and the contents were mixed rapidly by inversion.