11:00 AM - 1:00 PM
[HTT18-P11] Isotopic measurement of ultra-trace level Sr
Keywords:Sr, isotope analysis, ultra trace
Since Sr with a radiogenic isotope (87Sr) has geographical information, it has been successfully used as a tracer for environmental traceability research for tracking the movement history of living organisms and determining the origin of agricultural products. Therefore, researchers in various fields try to evaluate the possibility of a tracer for diverse types of samples, that have not been considered until now. Milli meter size insects such as aquatic insects and flies are one of the examples.
The problem is that such organisms often do not have a Sr-rich calcium carbonate-based skeleton, and may not have sufficient Sr content for Sr isotope ratio measurements. Since stable and accurate measurement is difficult for such samples, it is necessary to develop a method that enables stable measurement even with a small amount of Sr.
I report about the test of how accurate the isotope ratio can be measured with a small amount of Sr, using three devices (TIMS: Triton, Triton XT, MC-ICP-MS: Neptune) installed at the RIHN (Research Institute for Humanity and Nature).
Before trying a trace sample, I tested using the isotope standard NIST SRM 987 with various measurement conditions repeatedly, including changing the signal intensity of 88Sr to 0.1V, 0.3V, 0.5V. The results confirmed that at least 0.5V signal intensity for Triton, 0.3V for Triton XT, and 0.1V for Triton XT using 1013Ω Amplifier are required to obtain stable measured values. In MC-ICP-MS, the measurement was performed with 1 ml of Sr concentration 2 ppb solution (2 ng) using a desolvation inlet system, but the result shows a large deviation from the recommended value due to interference by various ions including Krypton (Kr) which existing in argon gas as an impurity.
The problem is that such organisms often do not have a Sr-rich calcium carbonate-based skeleton, and may not have sufficient Sr content for Sr isotope ratio measurements. Since stable and accurate measurement is difficult for such samples, it is necessary to develop a method that enables stable measurement even with a small amount of Sr.
I report about the test of how accurate the isotope ratio can be measured with a small amount of Sr, using three devices (TIMS: Triton, Triton XT, MC-ICP-MS: Neptune) installed at the RIHN (Research Institute for Humanity and Nature).
Before trying a trace sample, I tested using the isotope standard NIST SRM 987 with various measurement conditions repeatedly, including changing the signal intensity of 88Sr to 0.1V, 0.3V, 0.5V. The results confirmed that at least 0.5V signal intensity for Triton, 0.3V for Triton XT, and 0.1V for Triton XT using 1013Ω Amplifier are required to obtain stable measured values. In MC-ICP-MS, the measurement was performed with 1 ml of Sr concentration 2 ppb solution (2 ng) using a desolvation inlet system, but the result shows a large deviation from the recommended value due to interference by various ions including Krypton (Kr) which existing in argon gas as an impurity.