Abstract:Titanium alloys are commonly used as medical implants, and the presence of these implants may lead to an increase in titanium levels in the blood. The abundant elements such as calcium, phosphorus, and sulfur in serum can cause isobaric and polyatomic ion mass spectrometry interferences, severely affecting the accuracy of inductively coupled plasma mass spectrometry (ICP-MS) in determining titanium levels in human serum. This article establishes a method for determining serum titanium using dynamic reaction cell inductively coupled plasma mass spectrometry (DRC-ICP-MS) technology. By screening, ammonia gas was determined as the reaction gas, and the impact of gas flow rate and rejection parameter (RPq) on titanium content determination was optimized. The results show that using NH3 as the reaction gas and leveraging the characteristics of ion-molecule reactions to convert titanium ions into complexes of titanium and ammonia can successfully eliminate interference, with the recovery rate of titanium maintained between 80% and 120%. Based on the optimization of the detection limit and quantitation limit, the optimal mass number of 48Ti(NH)(NH3)4+ (m/z 131) was selected for analysis, with detection and quantitation limits of 0.012μg/L and 0.037μg/L, respectively. The accuracy of the method was verified by standard material testing and standard addition recovery rate, with six determinations made on two serum reference materials, resulting in RSDs of 2.9% and 1.3%, and standard addition recoveries ranging from 94.0% to 113.6%. The experimental results indicate that, compared with the standard mode, the mass transfer mode using ammonia gas can effectively remove interference, with good sensitivity and detection limits. This method can be used for the accurate determination of trace titanium in serum.