莨纱绸生产用河泥关键成分的定量方法

Quantitative method for key components of river mud used in the production ofgambiered Guangdong silk

为了快速有效评价莨纱绸生产用河泥的品质,本文开发了一种基于比色法的莨纱绸生产用河泥关键有机成分(腐殖酸和富里酸)的定量检测方法。研究了反应试剂福林酚与碳酸钠溶液的用量、反应温度和反应时间等对显色反应结果的影响,并进行了方法学检验。研究结果表明,测试10.0 mg河泥样品,最佳反应条件为:1.0 mL、1 mol/L福林酚,0.6 mL、150 mg/mL碳酸钠溶液,3.4 mL去离子水,40℃、40 kHz超声处理条件下反应60 min,检测波长760 nm。在标准物质量浓度为0.12~0.30 mg/mL时线性相关性良好,线性相关系数为0.99834。该方法的稳定性和重复性较好,RSD值分别为0.68%、1.43%;平均加标回收率为102.96%,RSD值为3.41%。利用此方法测得佛山顺德和西樵地区河泥(莨纱绸生产用泥)及杭州下沙河泥(非莨纱绸生产用泥)中关键有机成分的总含量分别为9.64%、5.61%和1.88%,与分离称重法所得的结果相近。

The content of key components(humic acid and fulvic acid)in river mud to a certain extent affects the quality of river mud used for the production of gambiered Guangdong silk,so it is necessary to determine the content of humic acid and fulvic acid in river mud.The commonly used quantitative methods for humic acid and fulvic acid are complex or have limitations,so this study attempts to use new methods for quantification.Under alkaline conditions,phenolic substances in the Folin-Ciocalten reagent will reduce Mo 6+and W 6+,resulting in a blue color.The depth of the color is proportional to the concentration of the reactive phenolic substances.Finally,its content can be indirectly determined by testing its absorbance.Therefore,this study first determined the testing wavelength through UV-VIS spectroscopy,and then explored the optimal process conditions for the reaction,including factors such as the amount of Folin-Ciocalten reagent and sodium carbonate solution,reaction temperature,reaction time,and the use of ultrasound.Then,under the optimal conditions,the standard curve of humic acid and fulvic acid purification product was determined,and finally,the stability,repeatability,and spiked recovery rate of this method were evaluated,in order to conduct a simple and rapid quantitative detection of the key components of river mud used in the production of gambiered Guangdong silk.According to the UV-VIS spectrum,under alkaline conditions,the Folin-Ciocalten reagent has a maximum absorption peak at 760 nm after reacting with river mud or standard solution,and there is no peak before the reaction.When the dosage of Folin-Ciocaltenl is below 1.0 mL,the absorbance increases significantly with the increase of Folin-Ciocalten dosage,while when the dosage of Folin-Ciocalten is above 1.0 mL,the absorbance remains stable and no longer increases.As the concentration of sodium carbonate increases,the absorbance shows a trend of first increasing and then decreasing.When the concentration of sodium carbonate in the total solution is 18 mg/mL,the absorbance value is the highest.Under ultrasonic treatment at 40℃and 40 kHz,the reactants in the river mud are more completely extracted,and the absorbance value at stability is significantly increased.The reaction rate is accelerated,and the time required for absorbance to reach stability is one hour.When the standard concentration ranges from 0.12 to 0.30 mg/mL,the fitting equation is Y=1.30476 X+0.26943,and the correlation coefficient R 2=0.99834.After testing,the stability and repeatability of this method are good,with RSD values of 0.68%and 1.43%,respectively.The average spiked recovery rate is 102.96%,and RSD is 3.41%.With this method,the total content of humic acid and fulvic acid in the river mud of Shunde,Xiqiao,and Xiasha is measured to be 9.64%,5.61%,and 1.88%,respectively.There are still a small amount of humic acid and fulvic acid in humin and other insoluble substances that cannot be removed,accounting for 1.97%,1.76%,and 1.36%,respectively in the river mud of Shunde,Xiqiao,and Xiasha.This study explores the method and reaction conditions for quantitative detection of key components in river mud based on the Folin-Ciocalten method.The results show that the optimal reaction conditions for testing 10.0 mg of river mud are:1.0 mL 1 mol/L Folin-Ciocalten,0.6 mL 150 mg/mL sodium carbonate solution,3.4 mL deionized water,40 kHz ultrasound treatment at 40℃for 60 minutes,and testing at 760 nm in the UV visible spectrum.Within a certain concentration range of standard substances,the correlation between concentration and absorbance is good.By testing the stability,repeatability,and spiked recovery rate of this method,it is determined that it is scientifically feasible.The total content of humic acid and fulvic acid in the mud of Shunde,Xiqiao,and Xiasha River in Foshan is measured by this method,and it is similar to the content of the actually extracted humic acid and fulvic acid.