摘要
采用实验室研制的激光共振电离质谱仪,建立了锡(Sn)同位素的激光共振电离质谱分析方法。测量了锡原子的自电离态光谱,确认了锡的一条三色三光子共振电离路径,其各步激发/电离的激光波长分别为λ_1=286.4 nm、λ_2=811.6 nm、λ_3=823.7 nm;通过将样品与氧化石墨烯溶液混合制样,有效提高了锡样品的电热原子化效率,1μg锡的总探测效率达到3×10~(-5)以上,是直接滴样方式的4.5倍左右。采用本方法对锡、锑、碲(1∶1∶1,m/m)混合模拟样品进行测试,实现了锡的选择性电离,有效避免了测量过程中锑、碲对锡的同量异位素干扰,样品中主要同位素比~(116)Sn/~(120)Sn,~(117)Sn/~(120)Sn,~(118)Sn/~(120)Sn和~(119)Sn/~(120)Sn测量的相对标准偏差均<1%。结果表明,本方法能够有效解决TIMS、ICP-MS等商业质谱仪在锡同位素质谱分析过程中的同量异位素干扰难题,有望应用于反应堆乏燃料中裂变产物~(121)mSn、~(126)Sn的测量。
A preliminary method based on the laser resonance ionization mass spectrometer( LRIMS)developed in the laboratory was established to determine tin isotope ratios. By measuring the auto-ionization spectrum of tin atoms,a three-color-three-photon resonance ionization scheme was confirmed,and the laser wavelengths of each excitation / ionization step were λ_1=286.4 nm、λ_2=811.6 nm、λ_3=823.7 nm. More effective electrothermal atomization of tin was implemented by mixing the samples and grapheme oxide solution,and the total detection efficiency of 1 μg of tin sample was above 3×10~(-5),which was about 4.5 times as high as the method of directly dropping samples. A tin-antimony-tellurium mixture at a ratio of 1 ∶ 1 ∶ 1( m/m) was prepared as a simulant sample,and the major tin isotope ratios in the sample were determined.Results showed that the isobaric interference from antimony and tellurium was effectively avoided,and the relative standard deviations for ~(116)Sn/~(120)Sn,~(117)Sn/~(120)Sn,~(118)Sn/~(120)Sn and ~(119)Sn/~(120)Sn were all better than 1%.This work indicated that LRIMS could effectively avoid the isobaric interference in the measurement of tin isotope ratios,and could be applied to measure the fission product ~(121)mSn and ~(126)Sn in the reactor spent fuel.
引文
1 Yamazaki E,Nakai S,Yokoyama T,Ishihara S,Tang H F.Geochem.J.,2013,47:21-35
2 LIANG Bang-Hong,ZHANG Jin-Song,LI Yi-Cai,CHEN Yun-Ming,ZHANG Ge,DU Wen-He.Journal of Chinese Mass Spectrometry Society,2012,33(6):349-352梁帮宏,张劲松,李已才,陈云明,张舸,杜文鹤.质谱学报,2012,33(6):349-352
3 ZHANG Sheng-Dong,LIU Jun-Ling,GUO Jing-Ru,LI Jin-Ying,CUI An-Zhi,LI Da-Ming,MAO Guo-Shu.Journal of Nuclear and Radiochemistry,2000,22(3):129-135张生栋,刘峻岭,郭景儒,李金英,崔安智,李大明,毛国淑.核化学与放射化学,2000,22(3):129-135
4 Malinovskiy D,Moens L,Environ V F.Sci.Technol.,2009,43:4399-4404
5 Hernńndez C,Fernández M,Quejido A J,Sánchez D M,Morante R,Martín R.Anal.Chim.Acta,2006,571:279-287
6 SHEN Hong-Tao,JIANG Shan,HE Ming,DONG Ke-Jun,WU Shao-Yong,HE Guo-Zhu,LI Zhen-Yu,LI Chao-Li,HE Xian-Wen,ZHANG Wei.Atomic Energy Science and Technology,2012,46(2):155-159沈洪涛,姜山,何明,董克君,武绍勇,贺国珠,李振宇,李朝历,何贤文,张伟.原子能科学技术,2012,46(2):155-159
7 Hurst G S,Payne M G,Nayfeh M H,Judish J P,Wagner E B.Chem.Phys.Lett.,1975,75(3):468-472
8 Hurst G S,Payne M G,Kramer S D,Young J P.Rev.Mod.Phys.,1979,51(4):767-819
9 Letokhov V S,Ambartzumian R V.Appl.Opt.,1972,11(2):354-361
10 Beekman D W,Callcott T A,Kramer S D,Arakawa E T,Hurst G S,Nussbaum E.Int.J.Mass Spectrom.Ion Phys.,1980,34(1):89-97
11 Crowther S A,Mohapatra R K,Turner G,Blagburn D J,Kehm K,Gilmour J D.J.Anal.At.Spectrom.,2008,23:938-947
12 Iwata Y,Ito C,Harano H,Aoyama T.Int.J.Mass Spectrom.,2010,296:15-20
13 Stephan T,Trappitsch R,Davis A M,Pellin M J,Rost D,Savina M R,Yokochi R,Liu N.Int.J.Mass Spectrom.,2016,407:1-15
14 Eichler B,Hübener S,Erdmann N,Eberhardt K,Funk H,Herrmann G,Khler S,Trautmann N,Passler G,Urban F J.Radiochim.Acta,1997,79(4):221-233
15 Saloman E B.Spectrochim.Acta,1992,47B(4):517-545
16 Scheerer F,Albus F,Ames F,Kluge H J,Trauemann N.Spectrochim.Acta B,1992,47(6):793-797
17 Perkins J F.Phys.Rev.A,1970,2(5):1704-1707
18 Payne M G,Allman S L,Parks J E.Spectrochim.Acta B,1991,46(11):1439-1457
19 Sankari M.Int.J.Optics,2011,2011:1-10