Determination of the Memory Effect and Stability of Mercury by ICP-MS / 中国药学杂志

ABSTRACT

OBJECTIVE: To investigate the effect of adding gold when determing the memory effect and stability of mercury by ICP-MS, and determine the appropriate amount of gold. METHODS: ICP-MS method was used to determine the amount of mercury in the solution. The RF power was 1 550 W, flow rate of carrier gas was 1.05 L•min-1, plasma gas flow rate was 15.0 L•min-1, peristaltic pump speed was 0.2 r•s-1, and sampling depth was 8 mm. The integration time was 0.1 s. RESULTS: Mercury solution began to demonstrate obvious memory effect at the concentration of 0.4 ng•mL-1. It gradually became unstable and the coefficient of variation gradually increased after being placed at room temperature for more than 2 h in the absence of stabilizer. After adding gold, the mercury soulution was stable within 48 h, and the coefficient of variation was within 5%. When the ratio of gold to mercury was 2∶1, the memory effect of mercury was decreaed, and its stability was well guaranteed. There was no difference when the mercury standard solution was prepared with or without other elements. CONCLUSION: This study plays a reference role in the detection and analysis of mercury and provides technical support for the revision and improvement of relevant detection methods.