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Determination of Piperine by UV-1300PC Ultraviolet Spectrophotometry

Key words: ultraviolet spectrophotometry; piperine; aesthetic instrument ; UV-1300PC

Src="http://i.bosscdn.com/blog/nophoto.gif" /></p> Abstract: This paper studies the ethanol solution of piperine with a sensitive absorption peak in the ultraviolet region and its maximum absorption wavelength. At 342 mm, a simple, rapid, and selective method for determining the content of piperine in pepper is established. The concentration of piperine in this method is in accordance with Beer's law in the range of 0-70 μg/ml. At present, the commercially available pepper powder is doped with more fakes, and the measurement methods are mostly qualitative methods. Quantitative analysis of piperine in pepper used to have thin-layer UV scanning method and colorimetric method. The former is limited by instrument conditions, and some grassroots units are still difficult to popularize. The latter is more complicated than the former. This paper introduces an easy-to-promote direct UV photometric method that is simple, fast, and accurate. 1 Reagents and instruments 1.1 Reagents anhydrous ethanol, activated carbon, piperine standard stock solution. Accurately weigh 0.1000g of piperine dissolved in a volumetric flask with absolute ethanol, and make up to 100ml; use the standard solution of piperine as a solution to absorb 10.0ml of the stock solution in a 100ml volumetric flask and dilute to the mark with absolute ethanol. 1.2 Instrument V-1300 spectrophotometer 2 Experimental method 2.1 Standard curve preparation Take 0.00, 0.05, 0.10, 0.30, 0.50, 0.70 ml of piperine standard use solution in 10.0ml colorimetric tube, with anhydrous Dilute the ethanol to the mark and mix. The absorbance was measured at a wavelength of 342 nm using a 1 cm cuvette with absolute ethanol as a reference, and a standard curve was drawn. 2.2 Extraction and determination of piperine in the sample Accurately weigh about 0.1g of the sample pulverized and passed through the 100 mesh sieve in a 50ml beaker. Add 0.1g of activated carbon and add a small amount of absolute ethanol. Be careful on the electric furnace. Hot to boiling. The mixture was filtered in a 100 ml volumetric flask, rinsed with a small amount of absolute ethanol, and the volume was adjusted to the mark and mixed. Then, pipette 5 ml into a 10 ml colorimetric tube, dilute to the mark with absolute ethanol, and shake well. The following procedure was carried out in the same manner as the standard curve preparation, and spectrophotometry was carried out. 3 Results and discussion 3.1 Absorption spectroscopy The experimental results show that the absorption spectrum of piperine in anhydrous ethanol medium has a maximum absorption wavelength λmax of 342 nm, which is determined at this wavelength. 3.2 Selection of the amount of activated carbon The color of the sample has a certain influence on the absorbance. The activated carbon is decolorized and the color is filtered. The effect is good. Five colored samples of the same piperine content were added, and activated carbon 0.0, 0.1, 0.2, 0.3, and 0.4 g were added respectively. Experiments show that the decolorization effect of adding 0.1g of activated carbon is good; the decolorization is less than 0.1g; the absorbance is less than 0.2g. Therefore, the amount of activated carbon used in this experiment is 0.1g. 3.3 Solvent selection Using anhydrous ethanol and 1.2 ~ dichloroethane as solvents, the experiment shows that the absorption spectra of the two solvents are similar, there is no significant difference. Since 1.2 ~ dichloroethane has a certain toxic effect on the human body, anhydrous ethanol is used as a solvent. 3.4 Selection of Ethanol Concentration Ethanol concentration has a great influence on the absorbance. When extracting piperine from pepper, this paper selects 10%, 30%, 50%, 80% of absolute ethanol as solvent, and experiments on the same amount of sample. . Experiments show that: 10%, 30% extract turbid, affecting colorimetric; 50%, 80% and absolute ethanol extracts are transparent, but the absorption peak of anhydrous ethanol extract at 342nm is the largest, so this paper chooses Anhydrous ethanol is used as a solvent. 3.5 Standard curve Experiments show that Beer's law is observed in the range of 0 to 70 μg/ml. The correlation coefficient was calculated by regression analysis with r=0.9998, and the minimum detection limit was 5μg/ml. 3.6 Precision 2 samples were taken and 7 parallel determinations were performed according to the operation method at different times. The relative standard deviation was 2.1 to 4.3%. 3.7 Accuracy of the method The test samples were added with different amounts of piperine. According to this method, the recovery rate is 94.2～96.9%, with an average of 94.5% 3.8. Interference in the three solutions of known piperine content, respectively, adding 0.1g of chili powder, cinnamon powder and fennel powder, according to this method. Operation, the measured result is reduced by 1.5 to 1.7% than the original, indicating that there is basically no interference. Key words: ultraviolet spectrophotometry; piperine; aesthetic instrument ; UV-1300PC</p> </div> </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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