UV-1100 UV spectrophotometer for the detection of thiophanate-methyl and carbendazim in fruit

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Ultraviolet spectrophotometer for the detection of thiophanate-methyl and carbendazim in fruit

Ultraviolet spectrophotometer for the detection of thiophanate-methyl and carbendazim in fruit: UV spectrophotometer; fruit; thiophanate-methyl and carbendazim; analysis instrument ; UV-1100; UV-1200

$Width="835" height="338" src="http://i.bosscdn.com/blog/nophoto.gif" /></p> Move the liquid into a 125ml separatory funnel. Extract twice with dichloromethane, 10 ml each time. The methylene chloride layer was sucked out with a needle-nosed pipette and transferred to a spare dry separatory funnel. The above acid solution was neutralized with 2 mol/L sodium hydroxide, and the pH was adjusted to 6.0-6.5 (the amount of the lye was 25 m1), and the neutralization was carried out. The liquid was extracted twice with dichloromethane, 20 ml each time, and the two extracts were combined together, and the separatory funnel was washed with 10 ml of distilled water, and after standing layering, the dichloromethane layer was merged into another one. In the separatory funnel of the methyl chloride layer. Accurately add 10 ml of hydrochloric acid at a concentration of 1 mol/L, extract again for 5 minutes, and let stand for about 10 minutes. After layering, the acid extract was poured into a 1 cm quartz two-color cup, the zero point of the spectrophotometer was adjusted with 1 mol/L hydrochloric acid, and the absorbance of 0-50 Î¼g of thiophanate-methyl standard solution was measured at a wavelength of 282 nm (A282). ). The standard curve of thiophanate-methyl was prepared by taking the A282 value as the ordinate and the content of thiophanate-methyl as the abscissa. Accurately absorb 0.0, 0.1, 0.3, 0.5ml carbendazim standard use solution (equivalent to 0, 10, 30, 50Î¼g carbendazim), put it into the separatory funnel, add 20ml of hydrochloric acid with a concentration of 1mol / L, Dichloromethane was extracted twice with 10 ml each time. The methylene chloride layer was aspirated with a pipette and transferred to a dry separatory funnel. The acid solution was neutralized to a pH of 6.0 to 6.5 with a 2 mol/L sodium hydroxide solution, extracted twice with dichloromethane, 20 ml each time, and the extract was washed once with 10 ml of distilled water. After standing to separate the layers, the two dichloromethane layers were combined, and 10 ml of hydrochloric acid having a concentration of 1 mol/L was accurately added, and acid extraction was further carried out for 5 minutes. Let stand for 10 minutes. After stratification, the acid extract was poured into a 1 cm quartz two-color cup, and the zero point of the spectrophotometer was adjusted with 1 mol/L hydrochloric acid. The absorbance value (A282) of 0-50 Î¼g of carbendazim standard solution was measured at a wavelength of 282 nm. The standard curve of carbendazim was plotted with the A282 value as the ordinate and the carbendazim content as the abscissa. UV-1100; UV-1200 3.2 Determination of thiophanate-methyl and carbendazim content in the fruit Take the dichloromethane extract of the pulp, naturally dry or heated to dry, then use 10ml of copper acetate-acetate solution Dissolve the residue in portions and transfer to a 30ml round bottom centrifuge, add 2-5 glass beads, connect to the air condenser tube, and slowly boil for 30 minutes with alcohol lamp or micro electric furnace. Use 20ml concentration of 1mol/L. Hydrochloric acid was washed from the top of the condenser tube to the condenser tube and the round bottom centrifuge tube for 2 minutes. The liquid was transferred to a 125 ml separatory funnel and extracted twice with dichloromethane for 10 ml each time. The methylene chloride layer was aspirated with a pipette tip and transferred to a spare dry separatory funnel. The above acid solution was neutralized with 2 mol/L of sodium hydroxide to adjust the pH to 6.0-6.5 (the amount of the lye was 25 ml). The neutralized solution was extracted twice with dichloromethane, 20 ml each time, and the two extracts were combined together, and the separatory funnel was washed with 10 ml of distilled water, and after standing layering, the dichloromethane layer was merged into another In a separatory funnel containing a dichloromethane layer, 10 ml of hydrochloric acid having a concentration of 1 mol/L was accurately added, and extracted again for 5 minutes, and allowed to stand for about 10 minutes. After layering, the acid extract was poured into a 1 cm quartz two-color cup, and the spectrophotometer zero was adjusted with 1 mol/L hydrochloric acid. The absorbance of the sample was measured at a wavelength of 282 nm. The content of thiophanate-methyl in the sample was calculated in comparison with the standard curve of thiophanate-methyl. UV-1100; UV-1200 UV spectrophotometer takes the carbendazim determination solution in the "extraction and separation of the sample to be tested", neutralized with a 2mol / L ammonium hydroxide solution to a pH of 6.0-6.5, with Dichloromethane was extracted twice, 20 ml each time, and the extract was washed once with 10 ml of distilled water. After standing to separate the layers, the two dichloromethane layers were combined, and 10 ml of a concentration of 1 mol/L hydrochloric acid was accurately added, and acid extraction was again carried out. minute. After standing for 10 minutes, after layering, the acid extract was poured into a 1 cm quartz two-color cup, and the zero point of the spectrophotometer was adjusted with 1 mol/L hydrochloric acid. The absorbance of the sample was measured at a wavelength of 282 nm. The content of carbendazim in the sample was calculated in comparison with the standard curve of carbendazim. UV-1100; UV-1200 UV spectrophotometer measurement results are calculated as follows: x = V1 Ã— C / m Ã— V2 Ã— 100 where Vl is the total number of milliliters added to the extraction solvent; m is the sample weight (g); V2 is the number of milliliters of the extraction solvent used in the measurement; C is equivalent to the standard concentration (mg); and x is the content of thiophanate-methyl (mg/kg) in the sample. Key words: ultraviolet spectrophotometer; fruit; thiophanate-methyl and carbendazim; analysis instrument ; UV-1100; UV-1200</p> </div> </div> <div Class="tech-detail-share">  <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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