Artigo
Flow-injection spectrophotometric determination of novalgin in phrmaceuticals using micellar medium
Fecha
2007-12-01Registro en:
Analytical Sciences. Tokyo: Japan Soc Analytical Chemistry, v. 23, n. 12, p. 1383-1389, 2007.
0910-6340
10.2116/analsci.23.1383
WOS:000251831500005
WOS000251831500005.pdf
8540599256820672
5978908591853524
0000-0003-0197-7369
Autor
Universidade Estadual Paulista (Unesp)
Resumen
A sensitive flow-injection (FI) procedure with spectrophotometric detection in a micellar medium is proposed for the determination of novalgin. The method is based on the instantaneous formation of a red-orange product (lambda(max) = 510 nm) after the reaction between novalgin and p-dimethylaminocinnamaldehyde (p-DAC) in a dilute acid medium. The sensitivity of this reaction was increased by a factor of 5.6 in the presence of sodium dodecyl sulfate (SDS). Experimental design methodologies were used to optimize the chemical and FI variables. The calibration curve was linear in the range of 1.45 x 10(-6) to 2.90 x 10(-5) mol L-1 with an excellent correlation coefficient (r = 0.9999). The detection limit was 1.31 x 10(-7) mol L-1 (n = 20, RSD = 2.0%). No interferences were observed from the common excipients. The results obtained by the proposed method were favorably compared with those given by the iodometric reference method at 95% confidence level.