UV-1100 UV-visible spectrophotometric determination of eucommia chlorogenic acid content - Database & Sql Blog Articles

UV-1100 UV-Vis Spectrophotometric Determination of Eucommia Acid

Key words: UV-visible spectrophotometry; secondary chlorogenic acid; aesthetic analyzer ; UV-1100; UV-1200

</p> At present, there are many methods for determining the content of chlorogenic acid, such as capillary electrophoresis, HPLC, visible spectrophotometry and paper chromatography-ultraviolet-visible spectrophotometry. However, the sample treatment is carried out by Soxhlet reflux extraction, followed by chromatography and separation. Long time and low efficiency. In this paper, the chlorogenic acid content was determined by UV-visible spectrophotometry, and only ultrasonic extraction was performed for one hour. Direct measurement without separation and purification, with fast and accurate, good stability, etc., suitable for large-scale sample analysis and testing. 1 Materials and methods UV-visible spectrophotometer: UV-1100 (Analysis China); ultrasonic scrubber: MS-5000 (Japan); methanol (AR) (Hunan Normal University Reagent Factory); chlorogenic acid standard. The test material Eucommia ulmoides leaves were collected in Jiangyan Forest Farm in May 1997. 2 Research methods 2.1 Wavelength selection According to the nature of chlorogenic acid soluble in water and methanol. Accurately weigh 10.1mg of chlorogenic acid standard, dissolve it with 50% methanol solution and dilute to 10ml and dilute it 10 times, then scan it in the range of 800-200nm. Take 50% methanol solution as reference and have the largest absorption bee at 325nm. In addition, the chlorogenic acid standard solution was spotted on a chromatography paper, and after using water as a developing agent, the fluorescent portion (ie, the chlorogenic acid portion) was removed from the ultraviolet lamp, and the remaining portion was ultrasonically extracted with a 50% methanol solution for 15 minutes. Using 50% methanol as a reference, scanning in the range of 800-200 nm, and having a maximum absorption peak at 345 nm, so 345 nm and 325 nm were selected, and the chlorogenic acid absorbance value was (ΔA=A325-A345). . 2.2 Preparation of the standard curve accurately weigh the appropriate amount of chlorogenic acid standard, diluted with 50% methanol solution into a standard solution containing chlorogenic acid 5.05, 10.1, 15.15, 20. 2, 30.3, 40.4μg per ml, 50% methanol solution for reference. A345 and A325 values ​​were measured at 325 nm 325 nm, and A (ΔA=A325-A345) was obtained. The concentration C (μg/ml) of the sample was plotted on the abscissa, and the absorbance ΔA was plotted on the ordinate. The A-C standard curve was drawn. The regression equation is obtained as: C = K ΔA + B, where K = 66.247, B = a 0.5808. 2.3 Determination of the sample Weigh accurately 0.5000 g of Eucommia leaf powder in a 60 ml test tube, add 40 ml of 50% methanol solution, and ultrasonically extract it for 15 min in an ultrasonic washer and filter. The filter residue was further added with 40 ml of a 50% methanol solution, and ultrasonically extracted for 15 minutes. The above operation was repeated four times (three parallels), and the combined filtrate was adjusted to a volume of 250 ml. The A325 and A345 values ​​were determined on a UV-visible spectrophotometer with 50% methanol as a reference to determine the chlorogenic acid content. 3 Results and analysis 3.1 Determination results 3.2 Stability test The sample was allowed to stand at room temperature for 24 hours and then measured, its absorbance value A did not change much, indicating that it was stable in 50% methanol solution. 3.3 Recovery experiment The standard sample is formulated into a certain concentration and added to the sample. The content was measured and the recovery was calculated. 4 Conclusions (1) The chlorogenic acid is between 5.05 and 40.4 μg/ml, and its absorbance △A=A325-A345 has a good linear relationship with the concentration. (2) The content of chlorogenic acid in Eucommia ulmoides leaves was determined by UV-Vis spectrophotometer. The stability and reproducibility were good, and the recovery was 104.2%. The method is simple, rapid, accurate and stable, and can be used for the determination of chlorogenic acid content in Eucommia ulmoides leaves. Key words: UV-visible spectrophotometry; secondary chlorogenic acid; aesthetic analyzer ; UV-1100; UV-1200</p> </div> <div class="tech-detail-share"> <!-- Baidu Button BEGIN --> <div class="bdsharebuttonbox"> <a href="#" class="bds_qzone" data-cmd="qzone" title="Share to QQ Space"></a> <a href="#" class="bds_tsina" data-cmd="tsina" title="Share to Sina Weibo"></a> <a href="#" class="bds_weixin" data-cmd=" Weixin" title="Share to WeChat"></a> <span>Share to:</span> </div> <script>window._bd_share_config = { "common": { "bdSnsKey": {}, "bdText ": "", "bdMini": "1", "bdMiniList": false, "bdPic": "", "bdStyle": "2", "bdSize": "16" }, "share": {} } ; with (document) 0[(getElementsByTagName(

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