液氮冷凝吸收热解-电感耦合等离子体质谱法测定岩石土壤沉积物中的溴碘
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摘要
分析地质样品中的溴碘,目前常用的提取方法有半熔法、稀氨水密封溶样法和热解法,但由于元素含量低、易损失,样品分解和溴碘的提取过程是主要的误差来源。本文改进了传统热解法的吸收装置,用液氮冷凝吸收代替常规的碱溶液吸收,提取地质样品中的溴碘,用电感耦合等离子体质谱法测定其含量。以标准偏差的10倍计算,稀释倍数为50,溴碘的检出限分别为0.06μg/g、0.01μg/g,低于传统热解法和半熔法,略高于稀氨水密封溶样法;精密度(RSD)为6.4%~21.0%。本方法相对于传统的碱溶液吸收热解法,减少了碱试剂的引入,降低了基体空白和稀释倍数,提高了精密度,操作较半熔法简便,可作为稀氨水密封溶样法的一种补充方法。因此,对于土壤和水系沉积物,宜采用稀氨水密封溶样法;对于岩石以及采用稀氨水密封溶样法难以完全提取的样品,可采用本方法。
The available extraction methods for the determination of Br and I in geological samples,include semifusion, aqua ammoniae closed digestion and pyrohydrolysis. The sample digestion and extraction of Br and I are the major error sources,due to the low content and volatization of Br and I. A pyrohydrolysis method with liquid nitrogen trap has been developed and used to extract Br and I in geological samples using liquid nitrogen condensation absorption replacing alkaline solution absorption. Br and I are measured by Inductively Coupled Plasma-Mass Spectrometry. The detection limits of Br and I are 0. 06 μg / g and 0. 01 μg / g,respectively,calculated as 10 times standard deviation using dilution times of 50. These detection limits are lower than those of traditional pyrohydrolysis and semifusion methods and slightly higher than those of aqua ammoniae closed digestion method. The precision is 6. 4%-21. 0% RSD. The proposed method reduces the use of alkaline solution,lowers the blank and dilution times,and improves the precision. This method is much simpler than the semifusion method and can serve as a complementary method for aqua ammoniae closed digestion method. For soils and stream sediments,aqua ammoniae closed digestion method is preferred. For rocks and samples that cannot be completely digested by aqua ammoniae closed digestion method,the proposed method may be more suitable.
The available extraction methods for the determination of Br and I in geological samples,include semifusion, aqua ammoniae closed digestion and pyrohydrolysis. The sample digestion and extraction of Br and I are the major error sources,due to the low content and volatization of Br and I. A pyrohydrolysis method with liquid nitrogen trap has been developed and used to extract Br and I in geological samples using liquid nitrogen condensation absorption replacing alkaline solution absorption. Br and I are measured by Inductively Coupled Plasma-Mass Spectrometry. The detection limits of Br and I are 0. 06 μg / g and 0. 01 μg / g,respectively,calculated as 10 times standard deviation using dilution times of 50. These detection limits are lower than those of traditional pyrohydrolysis and semifusion methods and slightly higher than those of aqua ammoniae closed digestion method. The precision is 6. 4%-21. 0% RSD. The proposed method reduces the use of alkaline solution,lowers the blank and dilution times,and improves the precision. This method is much simpler than the semifusion method and can serve as a complementary method for aqua ammoniae closed digestion method. For soils and stream sediments,aqua ammoniae closed digestion method is preferred. For rocks and samples that cannot be completely digested by aqua ammoniae closed digestion method,the proposed method may be more suitable.
引文
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[3]李冰,何红蓼,史世云,等.电感耦合等离子体质谱法同时测定地质样品中痕量碘溴硒砷的研究Ⅰ.不同介质及不同阴离子形态对测定信号的影响[J].岩矿测试,2001,20(3):161-166.Li B,He H L,Shi S Y,et al.Determination of Trace Iodine,Bromine,Selenium and Arsenic in Geological Samples by Inductively Coupled Plasma Mass SpectrometryⅠ.Signal Response of Different Anion Species in Mediums[J].Rock and Mineral Analysis,2001,20(3):161-166.
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[6]马新荣,李冰,韩丽荣.稀氨水密封溶解-电感耦合等离子体质谱测定土壤沉积物及生物样品中的碘溴[J].岩矿测试,2003,22(3):174-178.Ma X R,Li B,Han L R.Determination of Total Iodine and Bromine in Soil,Sediment and Biological Samples by Inductively Coupled Plasma Mass Spectrometry with Dilute Ammonia Pressurizing Decomposition[J].Rock and Mineral Analysis,2003,22(3):174-178.
[7]Chai J,Muramatsu Y.Determination of Bromine and Iodine in Twenty-three Geochemical Reference Materials by ICP-MS[J].Geostandards and Geoanalytical Research,2007,31(2):143-150.
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[9]Antes F G,Pereira J S F,Enders M S P,et al.Pyrohydrolysis of Carbon Nanotubes for Br and I Determination by ICP-MS[J].Microchemical Journal,2012,101(3):54-58.
[10]Müller C C,Nunes T S,Müller A L H,et al.Determination of Boron in Silicon Carbide by ICP-OES and ICPMS after Sample Preparation Using Pyrohydrolysis[J].Journal of the Brazilian Chemical Society,2015,26(1):110-116.
[11]Schnetger B,Muramatsu Y.Determination of Halogens,with Special Reference to Iodine,in Geological and Biological Samples Using Pyrohydrolysis for Preparation and Inductively Coupled Plasma Mass Spectrometry and Ion Chromatography for Measurement[J].Analyst,1996,121:1627-1631.
[12]Michel A,Villemant B.Determination of Halogens(F,Cl,Br,I),Sulfur and Water in Seventeen Geological Reference Materials[J].Geostandards and Geoanalytical Research,2003,27(2):163-171.
[13]Taflik T,Duarte F A,Flores E L M,et al.Determination of Bromine,Fluorine and Iodine in Mineral Supplements Using Pyrohydrolysis for Sample Preparation[J].Journal of the Brazilian Chemical Society,2012,23(3):488-495.
[14]Sekimoto S,Ebihara M.Accurate Determination of Chlorine,Bromine,and Iodine in Sedimentary Rock Reference Samples by Radiochemical Neutron Activation Analysis and a Detailed Comparison with Inductively Coupled Plasma Mass Spectrometry Literature Data[J].Analytical Chemistry,2013,85:6336-6341.
[15]孙江,饶文波,孙雪,等.新型沙漠土壤水分真空抽提装置的研制与应用[J].岩矿测试,2012,31(5):842-848.Sun J,Rao W B,Sun X,et al.A New Vacuum-distilled Extraction Apparatus for Desert Soil Water and Its Application[J].Rock and Mineral Analysis,2012,31(5):842-848.
[16]李贤琏,于振凡.氢化物-液氮冷凝富集-石墨炉原子吸收光谱法测定岩石、土壤及水样中微量锑[J].南京大学学报(自然科学版),1985,21(3):563-569.Li X L,Yu Z F.Determination of Trace Content of Antimony in Geologic Samples by Hydride-Graphite Furnace Atomic Absorption Spectrometry[J].Journal of Nanjing University(Natural Science Edition),1985,21(3):563-569.
[17]Tagami K,Uchida S.Sample Storage Conditions and Holding Times for the Determination of Total Iodine in Natural Water Samples by ICP-MS[J].Atomic Spectroscopy,2005,26(6):209-214.
[2]Balcone-Boissard H,Michel A,Villemant B.Simultaneous Determination of Fluorine,Chlorine,Bromine and Iodine in Six Geochemical Reference Materials Using Pyrohydrolysis,Ion Chromatography and Inductively Coupled Plasma Mass Spectrometry[J].Geostandards and Geoanalytical Research,2009,33(4):477-485.
[3]李冰,何红蓼,史世云,等.电感耦合等离子体质谱法同时测定地质样品中痕量碘溴硒砷的研究Ⅰ.不同介质及不同阴离子形态对测定信号的影响[J].岩矿测试,2001,20(3):161-166.Li B,He H L,Shi S Y,et al.Determination of Trace Iodine,Bromine,Selenium and Arsenic in Geological Samples by Inductively Coupled Plasma Mass SpectrometryⅠ.Signal Response of Different Anion Species in Mediums[J].Rock and Mineral Analysis,2001,20(3):161-166.
[4]Li B,He H L,Shi S Y,et al.Simultaneous Determination of Iodine,Bromine,Selenium and Arsenic in Geological Samples by Inductively Coupled Plasma Mass Spectrometry[J].Journal of Analytical Atomic Spectrometry,2002,17:371-376.
[5]安国荣,张启云,陈辉,等.ICP-MS测定溴、碘、砷和硒在多目标样品中的应用[J].光谱实验室,2013,30(6):3306-3308.An G R,Zhang Q Y,Chen H,et al.Determination of Bromine,Iodine,Arsenic and Selenium in Multi-purpose by ICP-MS[J].Chinese Journal of Spectroscopy Laboratory,2013,30(6):3306-3308.
[6]马新荣,李冰,韩丽荣.稀氨水密封溶解-电感耦合等离子体质谱测定土壤沉积物及生物样品中的碘溴[J].岩矿测试,2003,22(3):174-178.Ma X R,Li B,Han L R.Determination of Total Iodine and Bromine in Soil,Sediment and Biological Samples by Inductively Coupled Plasma Mass Spectrometry with Dilute Ammonia Pressurizing Decomposition[J].Rock and Mineral Analysis,2003,22(3):174-178.
[7]Chai J,Muramatsu Y.Determination of Bromine and Iodine in Twenty-three Geochemical Reference Materials by ICP-MS[J].Geostandards and Geoanalytical Research,2007,31(2):143-150.
[8]Picoloto R S,Cruz S M,Mello P A,et al.Combining Pyrohydrolysis and ICP-MS for Bromine and Iodine Determination in Airborne Particulate Matter[J].Microchemical Journal,2014,116:225-229.
[9]Antes F G,Pereira J S F,Enders M S P,et al.Pyrohydrolysis of Carbon Nanotubes for Br and I Determination by ICP-MS[J].Microchemical Journal,2012,101(3):54-58.
[10]Müller C C,Nunes T S,Müller A L H,et al.Determination of Boron in Silicon Carbide by ICP-OES and ICPMS after Sample Preparation Using Pyrohydrolysis[J].Journal of the Brazilian Chemical Society,2015,26(1):110-116.
[11]Schnetger B,Muramatsu Y.Determination of Halogens,with Special Reference to Iodine,in Geological and Biological Samples Using Pyrohydrolysis for Preparation and Inductively Coupled Plasma Mass Spectrometry and Ion Chromatography for Measurement[J].Analyst,1996,121:1627-1631.
[12]Michel A,Villemant B.Determination of Halogens(F,Cl,Br,I),Sulfur and Water in Seventeen Geological Reference Materials[J].Geostandards and Geoanalytical Research,2003,27(2):163-171.
[13]Taflik T,Duarte F A,Flores E L M,et al.Determination of Bromine,Fluorine and Iodine in Mineral Supplements Using Pyrohydrolysis for Sample Preparation[J].Journal of the Brazilian Chemical Society,2012,23(3):488-495.
[14]Sekimoto S,Ebihara M.Accurate Determination of Chlorine,Bromine,and Iodine in Sedimentary Rock Reference Samples by Radiochemical Neutron Activation Analysis and a Detailed Comparison with Inductively Coupled Plasma Mass Spectrometry Literature Data[J].Analytical Chemistry,2013,85:6336-6341.
[15]孙江,饶文波,孙雪,等.新型沙漠土壤水分真空抽提装置的研制与应用[J].岩矿测试,2012,31(5):842-848.Sun J,Rao W B,Sun X,et al.A New Vacuum-distilled Extraction Apparatus for Desert Soil Water and Its Application[J].Rock and Mineral Analysis,2012,31(5):842-848.
[16]李贤琏,于振凡.氢化物-液氮冷凝富集-石墨炉原子吸收光谱法测定岩石、土壤及水样中微量锑[J].南京大学学报(自然科学版),1985,21(3):563-569.Li X L,Yu Z F.Determination of Trace Content of Antimony in Geologic Samples by Hydride-Graphite Furnace Atomic Absorption Spectrometry[J].Journal of Nanjing University(Natural Science Edition),1985,21(3):563-569.
[17]Tagami K,Uchida S.Sample Storage Conditions and Holding Times for the Determination of Total Iodine in Natural Water Samples by ICP-MS[J].Atomic Spectroscopy,2005,26(6):209-214.