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在同位素地质中,用铷锶法测定岩石年龄,首先需对样品进行铷锶试测,以便从中挑选适于作等时线的样品。用原子吸收法可以简便、快速地满足这一要求。铷是亲石元素,它在地壳中的平均含量为0.03%,除花岗伟晶岩含铷较高、超基性岩含铷很低(<10ppm)外,铷在岩石中的含量一般只有10—2000ppm。用原子吸收法测定铷的灵敏度为0.01—0.1ppm。因铷的电离电位很低,仅4.16ev,而它的电离度很高,约为85%。所以,电离干扰是本法的主要干扰。加入浓度为2000ppm 的钾,可以有效地消除之。测铷的灵敏线有7800和7948,前者的灵敏度高于后
In isotope geology, the rubidium-strontium method is used to determine the rock age. The rubidium-strontium test should first be performed on the sample to select the sample suitable for isochron. With atomic absorption method can be simple and fast to meet this requirement. Rubidium is a lithophile element that has an average content of 0.03% in the earth's crust, with the exception that the granitic pegmatites contain high amounts of rubidium and the ultrabasic rocks contain very low levels of rubidium (<10 ppm) 10-2000ppm. The atomic absorption method for the determination of rubidium sensitivity of 0.01-0.1ppm. Due to the low ionization potential of rubidium, only 4.16ev, and its high degree of ionization, about 85%. Therefore, ionizing interference is the main disturbance of this law. By adding potassium at a concentration of 2000 ppm, this can be effectively eliminated. The sensitivity of rubidium measured 7800 and 7948, the former sensitivity is higher than the latter