Simultaneous quantification of six phenylethanoid glycosides in some Turkish Scutellaria species by a new HPLC-DAD method.

A new HPLC-DAD method was developed and validated for simultaneous determination of six main phenylethanoid glycosides (calceolarioside D, neocalceolarioside D, verbascoside, isoverbascoside, leucoseptoside A and martynoside) in the aerial parts of four Scutellaria L. taxa from flora of Turkey. All standard compounds showed a good linearity (R 2 > 0.999) in a relatively wide concentration range (1-120 µg/mL). The LOD of the compounds was in the range of 0.104-1.295 µg/mL and the LOQ was in the range of 0.450-2.536 µg/mL. The recoveries of the selected compounds were calculated in the range of 97.46-117.85%. The amounts of the phenylethanoid glycosides showed variation in the extracts. The developed method was found to be accurate, precise and reproducible, and successfully applied to identify and quantify the phenylethanoid glycoside composition of Scutellaria species.

Development and Validation of a High-performance Liquid Chromatography-Diode-array Detection Method for the Determination of Eight Phenolic Constituents in Extracts of Different Wine Species.

OBJECTIVES: A new HPLC method was developed and validated for the determination of some phenolic compounds; gallic acid, chlorogenic acid, epigallocatechin, caffeic acid, vanillin, p-coumaric acid, rutin, and quercetin in some local wine and fruit wine samples. MATERIALS AND METHODS: Analyses were performed on a Zorbax Eclipse C18 column (4.6 x 150 mm, 3.5-µm particle size) using a gradient system. Mobile phase A was a 10-mM phosphoric acid solution and mobile phase B was methanol using a flow rate of 1 mL/min. Phenolic components were monitored using a DAD at three different wavelengths. RESULTS: The developed and validated method was generally linear between the 1-100 ppm concentration range. Recovery values were obtained in the range of 95-105% and repetitive. The method was successfully applied to investigate the phenolic profiles of different wine samples. CONCLUSION: As a result of the study, an accurate, sensitive and reliable HPLC-DAD method was developed. The method was successfully used to determine the concentrations of antioxidant phenolic constituents from some local wine extracts.

Determination of benzalkonium chloride in wet wipes by using a validated capillary electrophoresis method.

Benzalkonium chloride (BAC), which is a mixture of C8 and C18 alkylbenzyldimethylammonium chlorides, has an important biocide character and is used in many cosmetics, especially wet wipes, as a preservative and/or antibacterial agent. The concentration range of BAC is 0.005­0.5 % and it is an irritant substance when used at high concentrations. Thus, the concentration of BAC should be carefully monitored in commercial products intended for skin use. In this study, a capillary electrophoresis (CE) analysis method for BAC quantification was developed. The quantitative analysis was carried out by the external standard method. The electrophoretic separation was performed by using 75 mM (pH 6.0) phosphate buffer solution containing 30% acetonitrile as the electrolyte. The separation voltage was 10 kV and the temperature was held at 18°C. Samples were introduced into the capillary column hydrodynamically using 50.0-mbar pressure over a 3-s period. The developed method was validated and applied on samples prepared by wringing out antibacterial wet wipes containing BAC without any further extraction. The linearity of the method was controlled by applying the Mandel test. The limit of detection (LOD) values for the developed method were 0.313 and 0.309 µg/ml and the limit of quantification (LOQ) values were 1.042 and 1.029 µg/ml for C10 and C12 derivatives, respectively.