A method for separation and isotopic determination of boron with low content and rich organic matter in the river/rain water samples was developed. Samples were concentrated by ion exchange Amberlite IRA-743 resin. The concentrated solution was subsequently micro-sublimated for 12 h to eliminate the organic matters. Then the boron isotope ratio was determined by measuring positive Cs(2)BO(2)(+) thermal ions. The average recovery was between 97. 5% and 101. 2%. The results that were determined by positive thermal ionization mass spectrometry were closed to those by MC-ICP-MS. The precision of isotopic measurement for boron in river/rain water was better than 0. 05 parts per thousand. The results demonstrated that this method was extremely effective for elimination organic matter interference during boron isotopic analysis with low sample size, high precision and accuracy.

Publication name	CHINESE JOURNAL OF ANALYTICAL CHEMISTRY　Volume:39 　Issue:4 　Pages:552-555　 Published:APR 2011
Author(s)	He Mao-Yong; Xiao Ying-kai; Zhao Zhi-Qi; Ma Yun-Qi; Xiao Jun; Zhang Yan-Ling; Luo Chong-Guang; Ma Hai-Zhou
Corresponding author	HE Maoyou  hemaoylzu2000@gmail.com  1. Chinese Acad Sci, State Key Lab Loess & Quaternary Geol, Inst Earth Environm, Xian 710075, Peoples R China  2. Chinese Acad Sci, Chinese Acad Sci Key Lab Salt Lake Resources & Ch, Qinghai Inst Salt Lakes, Xining 810008, Peoples R China  3. Chinese Acad Sci, State Key Lab Environm Geochem, Inst Geochem, Guiyang 550002, Peoples R China