Optimal Conditions for Determination of Fluoride in Plant Samples by Microwave Digestion Coupled with Ion Selective Electrode Method
-
摘要: 准确检测植物体内的氟含量有助于预测氟化物的生态环境效应。植物中的氟含量低，通常不超过300 μg/g，应用离子选择电极法测量氟需选择样品分解效率高的前处理方法使氟不受到损失，获得离子成分简单、空白低的溶液，同时加入适量的缓冲液增强氟离子的强度和掩蔽干扰。本文采用微波消解法处理植物样品，离子选择电极法测定氟的含量，通过优化实验条件确定了缓冲液的浓度。结果表明，在25℃、pH=6.5的样品溶液中加入147 g/L总离子强度缓冲溶液（TISAB）10 mL，避免了溶液中的阳离子与氟离子生成稳定的不溶絮状物，显著降低了沉淀物的产生。本方法检出限为0.242 μg/g，精密度（RSD）小于8.5%，回收率为92.0%～108%，能满足地球化学样品分析中对植物样品中低含量氟的检测要求。Abstract: It is helpful to predict the ecological and environmental effects of fluoride by accurately detecting the fluorine content in plants. Fluoride in plant samples is commonly lower than 300 μg/g. The chemical separation method with good separation effect should be selected to avoid the loss of F and determine the resulting solution with simple components and low blank when the method of microwave digestion coupled with Ion Selective Electrode Method is applied. Appropriate buffer solution is added to increase the intensity of fluoride ions and reduce screen interferences. Plant samples are digested by microwave, and fluoride is determined by Ion Selective Electrode Method, as reported in this paper. The concentration of buffer solution is defined by optimal conditions. Results show that the addition of 10 mL TISABⅡ solution of 147 g/L to the sample solution at 25℃ and pH of 6.5 can avoid the formation of stable insoluble floccule due to the reaction between cation and fluoride ions. The method has a relative standard deviation (RSD) of less than 8.5%, a detection limit of 0.242 μg/g and a recovery of 92.0%-108%, which meets the determination requirement of the low-content fluoride in plant samples.
-
-
表 1 TISAB Ⅱ缓冲液浓度对氟含量测量的影响
Table 1. Effect of TISAB Ⅱ concentration on determination of fluoride
缓冲液浓度(g/L) 空白电位值(mV) 氟的测定值(μg/g) GBW10015 GBW10016 GBW10020 GBW07602 294 -328 16.7 66.5 46.2 33.0 196 -347 14.8 58.7 39.1 25.0 147 -354 13.8 55.6 36.3 22.7 73.5 -368 12.6 47.1 29.3 18.7 49.0 -382 11.2 40.2 23.3 13.5 标准值 - 14.0 57.0 38.0 24.0 
下载: 导出CSV
表 2 方法精密度与准确度试验
Table 2. Precision and accuracy tests of the method
标准物质编号 氟的含量(μg/g) RSD(%) 相对误差(%) 标准值 测定平均值 GBW10015 14 13.5 3.4 -2.5 GBW10016 57 55.8 5.1 -2.1 GBW10020 38 39.1 7.8 3.0 GBW07602 24 23.1 8.4 -3.8
下载: 导出CSV
表 3 加标回收率试验
Table 3. Spiked recovery tests of the method
样品名称 氟的含量(μg/g) 回收率 原含量 加标量 测定量 核桃树叶 82.0 100.0 174 92.0 悬铃木树叶 122 100.0 216 94.0 小麦秸秆 2.52 1.00 3.45 93.0 玉米秸秆 4.70 5.00 10.1 108
下载: 导出CSV
-
[1] 王茜,石瑛,张猛,等.氟化物的危害及植物去氟作用研究进展[J].现代农业科技,2012(7):271-273. http://www.cnki.com.cn/Article/CJFDTOTAL-ANHE201207180.htm
Wang Q,Shi Y,Zhang M,et al.Harm of Fluoride and Research Progress on Purification by Plants[J].Modern Agricultural Science and Technology,2012(7):271-273. http://www.cnki.com.cn/Article/CJFDTOTAL-ANHE201207180.htm
[2] Davraz A,Sener E,Sener S.Temporal Variations of Fluoride Concentration in Isparta Public Water System and Health Impact Assessment (SW-Turkey)[J].Environmental Geology,2008,56:159-170. doi: 10.1007/s00254-007-1148-1
[3] 盛晓风,郭莹莹,尚德荣,等.离子选择电极法测定高氟样品中氟的方法改进[J].食品工业科技,2013,34(9):285-289. http://www.cnki.com.cn/Article/CJFDTOTAL-SPKJ201309062.htm
Sheng X F,Guo Y Y,Shang D R,et al.Improvement of Fluorine-Ion Selective Electrode Method for Determination of Fluorine in High Fluoride Samples[J]. Science and Technology of Food Industry,2013,34(9):285-289. http://www.cnki.com.cn/Article/CJFDTOTAL-SPKJ201309062.htm
[4] 覃建东,谢朝怀,郭健,等.干法消解测定桑叶中总氟化物[J].分析试验室,2007,26(增刊):31-33. http://www.cnki.com.cn/Article/CJFDTOTAL-FXSY2007S1011.htm
Qin J D,Xie C H,Guo J,et al.The Study of Dry Digestion Determination of Total Fluoride in Mulberry Leaves[J].Chinese Journal of Analysis Laboratory,2007,26(Supplement):31-33. http://www.cnki.com.cn/Article/CJFDTOTAL-FXSY2007S1011.htm
[5] 张楠,张凌云.茶叶中氟的安全性与检测方法研究进展[J].茶叶,2009,35(1):3-6. http://www.cnki.com.cn/Article/CJFDTOTAL-CHAY200901004.htm
Zhang N,Zhang L Y.Advance in the Study on the Detection and Safety of Fluoride in Tea[J].Journal of Tea,2009,35(1):3-6. http://www.cnki.com.cn/Article/CJFDTOTAL-CHAY200901004.htm
[6] 万红友,师会勤,周生路,等.总离子强度缓冲剂对含氟溶液 测定的影响[J].土壤通报,2004,35(3):380-382. http://www.cnki.com.cn/Article/CJFDTOTAL-TRTB200403033.htm
Wan H Y,Shi H Q,Zhou S L,et al.Measurement of Fluorine Liquid as Influenced by TISAB[J].Chinese Journal of Soil Science,2004,35(3):380-382. http://www.cnki.com.cn/Article/CJFDTOTAL-TRTB200403033.htm
[7] 李戎娟,刘东娜,李俊,等.氟离子选择电极法测定砖茶中氟含量的稳定性研究[J].食品安全质量检测学报,2013,4(4):1173-1178. http://www.cnki.com.cn/Article/CJFDTOTAL-SPAJ201304046.htm
Li R J,Liu D N,Li J,et al.Stability of Fluoride Ion Selective Electrode Method to Detect Fluorine Content in Brick Tea[J].Journal of Food Safety & Quality,2013,4(4):1173-1178. http://www.cnki.com.cn/Article/CJFDTOTAL-SPAJ201304046.htm
[8] 胡小玲,李莉.离子选择电极法测定植物叶片中的氟[J].化学分析计量,2008,17(3):48-49. http://www.cnki.com.cn/Article/CJFDTOTAL-HXFJ200803019.htm
Hu X L,Li L.Determination of Fluoride in Plant Leaves by Ion Selective Electrode Method[J].Chemical Analysis and Meterage,2008,17(3):48-49. http://www.cnki.com.cn/Article/CJFDTOTAL-HXFJ200803019.htm
[9] 刘亚轩,李晓静,白金峰,等.植物样品中无机元素分析的样品前处理方法和测定技术[J].岩矿测试,2013,32(5):681-693. http://www.ykcs.ac.cn/ykcs/ch/reader/view_abstract.aspx?file_no=20130504&flag=1
Liu Y X,Li X J,Bai J F,et al.Review on Sample Pretreatment Methods and Determination Techniques for Inorganic Elements in Plant Samples[J].Rock and Mineral Analysis,2013,32(5):681-693. http://www.ykcs.ac.cn/ykcs/ch/reader/view_abstract.aspx?file_no=20130504&flag=1
[10] 黄会秋.微波消解-氟离子选择电极法测定海产品中氟的研究[J].中国卫生检验杂志,2005,15(9):1088-1090. http://www.cnki.com.cn/Article/CJFDTOTAL-ZWJZ200509027.htm
Huang H Q.Study on the Determination of Fluorine by Microwave Digestion-Fluorine Ion Selective Electrode Method in Seafood[J].Chinese Journal of Health Laboratory Technology,2005,15(9):1088-1090. http://www.cnki.com.cn/Article/CJFDTOTAL-ZWJZ200509027.htm
[11] 林建原,杨剑.微波消解-氟离子选择电极法测定树叶中氟离子含量[J].广东微量元素科学,2008,15(2):59-63. http://www.cnki.com.cn/Article/CJFDTOTAL-GWYS200802013.htm
Lin J Y,Yang J.Determination of Fluoride Content in Plant Leaves by Microwave Digestion and Fluoride Ion-Selective Electrode Method[J].Guangdong Trace Elements Science,2008,15(2):59-63. http://www.cnki.com.cn/Article/CJFDTOTAL-GWYS200802013.htm
[12] Colina J M,Arias C F,Rodriguez A.The Influence of the Composition of the TISAB Solution on the Determination of Fluoride in Tea Infusions[J].Fluoride,1990,23(1):20. https://www.researchgate.net/publication/291152508_The_influence_of_the_composition_of_the_TISAB_solution_on_the_determination_of_fluoride_in_tea_infusions
[13] 郜红建,张显晨,蔡荟梅,等.水中氟化物测定过程中总离子强度调节缓冲液的对比与优化[J].环境化学,2010,29(4):754-758. http://www.cnki.com.cn/Article/CJFDTOTAL-HJHX201004042.htm
Gao H J,Zhang X C,Cai H M,et al.Comparison and Optimization of & Total Ionic Strength Adjustment Buffer for the Determination of Fluoride in Water[J].Environmental Chemistry,2010,29(4):754-758. http://www.cnki.com.cn/Article/CJFDTOTAL-HJHX201004042.htm
[14] 赵立晶,赵萍,魏月仙.流动分析-离子选择电极法测定水中痕量氟化物[J].分析化学,2011,39(10):1526-1530. http://www.cnki.com.cn/Article/CJFDTOTAL-FXHX201110015.htm
Zhao L J,Zhao P,Wei Y X.Determination of Trace Fluoride in Water with Flow Analysis-Ion Selective Electrode[J].Chinese Journal of Analytical Chemistry,2011,39(10):1526-1530. http://www.cnki.com.cn/Article/CJFDTOTAL-FXHX201110015.htm
[15] 曾泳淮,林树昌编著.分析化学(仪器分析分册)[M].北京:高等教育出版社,2004:259-279.
Zeng Y H,Lin S C.Analytical Chemistry (Instrumental Analysis)[M].Beijing:Higher Education Press,2004:259-279.
[16] 贺军四,黄永达,李鹏.离子选择电极测定氟离子方法的改进[J].铜业工程,2012(3):15-17. http://www.cnki.com.cn/Article/CJFDTOTAL-TYGC201203007.htm
He J S,Huang Y D,Li P.Improvement of Ion Selective Electrode on Fluorine Ions Method[J].Copper Engineering,2012(3):15-17. http://www.cnki.com.cn/Article/CJFDTOTAL-TYGC201203007.htm
[17] 刘毅,梁唐敏.pH值对氟化物离子选择电极法测定氟的影响[J].化工技术与开发,2014,43(1):45-46. http://www.cnki.com.cn/Article/CJFDTOTAL-GXHG201401014.htm
Liu Y,Liang T M.Effect of pH on Determination of Fluorine by Fluoride Ion Choosing Electrode Method[J].Technology & Development of Chemical Industry,2014,43(1):45-46. http://www.cnki.com.cn/Article/CJFDTOTAL-GXHG201401014.htm
-