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Sheila Hagerty, master's degree candidate in the forensic science program at Buffalo State, will hold her defense seminar, "Quantification of Trans-10-hydroxy-2-decenoic Acid and Adenosine in Royal Jelly Products Purchased in USA via HPLC," at 12:30 p.m. Thursday, May 8, in Science Building 272. An abstract of her presentation appears below.

This seminar is sponsored by the Faculty-Student Association.

Abstract
Quantitative analysis of trans-10-hydroxy-2-decenoic acid (10-HDA) and adenosine in pure form and dietary supplements of royal jelly available in the United States was carried out via reversed phase high performance liquid chromatography (RP-HPLC). The target compounds, 10-HDA and adenosine, in samples and their internal standards, methyl 4-hydroxybenzoate (MHB) and theophylline, were separated using a Zorbax Eclipse XDB-C18 column (150 × 4.6 mm) with a polar mobile phase. In the case of 10-HDA analysis, a mixture of methanol, water, and phosphoric acid (55:45:5, v/v/v) was used as a mobile phase. The flow rate was 1.0 mL/min and the UV detection was performed at 215 nm at 25°C. The average recovery rate of 10-HDA was 97.4 – 100.4% with the relative standard deviation (RSD) of 2.4 – 3.4% over the concentrations ranging from 10 to 80 mg/mL. The limit of detection (LOD) and limit of quantification (LOQ) were found to be about 0.05 and 0.25 mg/mL, respectively. The results show that the concentration of 10-HDA lies between 1.85 and 2.31% for pure royal jelly creams and between 0.43 and 6.28% for royal jelly supplements.

In this work, adenosine in samples was extracted by sonication in a mixture consisting of 5% ethanol and 95% deionized water and a mobile phase of 93% deionized water and 7% acetonitrile at 25 °C. Due to the self-association of adenosine, special attention was paid to optimize pH and compositions of extraction solvents and mobile phases. The flow rate of a mobile phase was set to 1.0 ml/min and the UV detection was performed at 260 nm. The average recovery rate of adenosine was 92.8 – 99.2% with the relative standard deviation (RSD) of 0.1 – 1.3% over concentrations ranging from 5 to 160 mg/ml. The limit of detection (LOD) and limit of quantification (LOQ) were found to be ~0.01 and ~0.05 mg/ml, respectively. Quantification was carried out using calibration curves constructed by both internal standard (ISTD) and external standard (ESTD) methods. The results show that the concentration of adenosine lies between ~27 and ~63 mg/g for pure royal jelly creams and between ~2 and ~174 mg/g for royal jelly supplements.