RESUMO
A new derivative spectrophotometric (DS) method was proposed and validated for quantification of total flavonoids from in O/W emulsion with polyacrylamide (and) C13-14 isoparaffin (and) laureth-7 containing Catuaba (Trichilia catigua Adr. Juss) (and) Marapuama (Ptychopetalum olacoides Bentham) extract. DS method was optimized to perform the assay in most favorable conditions. Linearity, specificity and selectivity, recovery (Rc, %), precision (R.S.D., %), accuracy (E, %), detection (LOD, microg ml(-1)) and quantification limits (LOQ, microg ml(-1)) were established for method validation. First-derivative at 388.0 nm (zero-to-peak; amplitude= +/- 0.12; wavelength range= 300.0-450.0 nm and Deltalambda = 4 nm) offered linearity for rutin concentrations ranging from 10.0 to 60.0 microg ml(-1) in ethanol 99.5%. Second-derivative provided to be unsuitable for interval evaluation obtaining unacceptable accuracy. Analytical method was validated for first-derivative, according to the experimental results: correlation coefficient (r = 0.9999); specificity to total flavonoids quantification, expressed in rutin, at wavelength 388.0 nm and selectivity with elimination of interference from matrix; Rc = 108.78%; intra- and inter-run precision (1.30-3.65% and 3.48-4.68%), and intra- and inter-run accuracy (100.00-112.19% and 101.25-118.44%); LOD = 0.62 microg ml(-1) and LOQ = 1.86 microg ml(-1).
Assuntos
Flavonoides/análise , Meliaceae , Olacaceae , Extratos Vegetais/química , Brasil , Emulsões , Óleos/química , Reprodutibilidade dos Testes , Rutina/análise , Espectrofotometria Ultravioleta/métodos , Água/químicaRESUMO
An ultraviolet spectrophotometric method was validated for total flavonoid quantitation, as rutin equivalents, present in the Trichilia catigua Adr. Juss (Meliaceae) and Ptychopetalum olacoides Bentham (Olacaceae) commercial extract. Parameters as linearity, interval (range), specificity, estimated limit of detection (LOD, microg/mL), estimated limit of quantitation (LOQ, microg/mL), recovery (R, %), precision or relative standard deviation (RSD, %), and accuracy (E, %) were established. The analytical method was validated according to the experimental results: correlation coefficient (r = 0.9997); interval (RSD = 0.15-0.47%; E = 98.98-101.24%); specificity to total flavonoids quantitation, as rutin equivalents, at wavelength 361.0 nm; LOD = 0.09 microg/mL and LOQ = 0.27 microg/mL; R = 99.36-102.14%; adequate intra- and interrun precision (0.30-0.49% and 0.31-0.81%), and intra- and interrun accuracy (100.60-102.38% and 98.58-100.38%).