利用表面热电离质谱仪(Triton TI)的“Zoom Quad”功能,采用静态多接收偏硼酸钯离子(Cs2BO2^+)测定标准样品NIST951 H3BO3和珊瑚与有孔虫样品的硼同位素,研究了涂样量对硼同位素组成测定的影响,探讨静态多接收与传统的动态峰跳扫方法相比,在测定精度、准确度、样品量以及测试时间上的优势。实验结果表明,在测试精度和准确度相同的情况下,静态双接收所需样品量可以低至0.1μg,且测试时间可缩短一半。对0.1μg NIST951 H3BO3静态双接收测定的硼同位素比值^11B/^10B=4.05159±0.00023(2σm,n=10),与世界主要实验室的测试值相符。最后对0.1μg珊瑚和有孔虫样品进行了测定,也取得了较好的结果。
A static double collector system and"Zoom Quad" function in the Finnigan-MAT Triton TI thermal ionization mass spectrometer was used to analyse different amounts of the boric acid standard NIST SRM 951 and natural samples, such as coral and foraminifera. The main objectives of the study were to discuss the difference of precision, accuracy, sample amount as well as testing time between static multicollection method and conventional peak jumping method. The experimental result indicated that in the same precision and the accuracy, the static double method is easier to measure small amount of sample as low as 0.1 μg, and reduces the data acquisition time to 20 min. The reproducibility of measured ^11 B/^10B ratios of NBS 951 boric acid with static multicollection is ^11B/^10B = 4. 05159 ±0. 00023 (2σm, n = 10) for 0.1 g of B. Finally 0. 1 g natural samples were analyzed with a good test.