2016-06-01, Tekkeli, S. E. Kepekci, Kiziltas, M. V., Dincel, DEMET, ERKOC, R., Topcu, GÜLAÇTI, TEKKELİ, ŞERİFE EVRİM, DİNCEL, DEMET, TOPÇU, GÜLAÇTI

Introduction: In patients with chronic kidney disease (CKD), uremic toxins accumulate in blood and cannot be excreted with urine. Accumulation of these toxins has negative effects on many body functions. Because of the importance of these toxins, we developed and validated a simple, sensitive, accurate, and precise method for the determination of two main uremic toxins:phenol and p-cresol in human urine. Materials and methods:Separation of these analytes in urine samples was achieved by reverse-phase high-performance liquid chromatography (RP-HPLC) with a C18 column at 35 degrees C using the mobile phase of methanol-water (65:35) at a flow rate of 1.4 mL min(-1). Fluorimetric detection was used at 284 nm for excitation and 310 nm for emission. Results:The method is linear over the range of 1.5-35 ng mL(-1) and 1-45 ng mL(-1) for phenol and p-cresol, respectively. The method was applied to urine samples from 10 healthy subjects and 10 chronic kidney disease patients. Conclusions:This assay appears to be useful in routine analysis of clinical samples for simultaneous determination of phenol and p-cresol levels in urine.

2019-06-01, Tekkeli, Serife Evrim Kepekci, DİNCEL, DEMET, Onal, Cem, Onal, Armagan, Sagirli, Olcay, DİNCEL, DEMET, TEKKELİ, ŞERİFE EVRİM

Current scientific studies indicate that carotenoids (CRTDs) are beneficial for maintaining health and lowering the risk of different pathologies. Considering the increasing role of carotenoids in healthcare, determination of carotenoid content of foods become important. Mostly, the analytical procedures that are used for this aim, are based on extraction techniques followed by different analytical procedures, especially high performance liquid chromatography. In this publication, a review of various analytical techniques developed for the determination of carotenoids in different food commodities starting from 2006 up to now, has been presented.