Determination of ultra-trace levels of titanium in human serum using inductively coupled plasma tandem mass spectrometry based on O2/H2 reaction gas

This study proposes a new strategy to determine ultra-trace Ti in human serum using inductively coupled plasma tandem mass spectrometry (ICP-MS/MS). The human serum samples were diluted with 1% (v/v) HNO3, followed by the determination of ultra-trace Ti using ICP-MS/MS. In the MS/MS mode, a small amount of H-2 was mixed with O-2 (the reaction gas) in a collision reaction cell (CRC) to form an O-2/ H-2 reaction mixture, and then, the conversion of Ti thorn to TiOthorn was determined by the O-2 mass shift method. High concentrations of Ca, S, and P in human serum were ionized in plasma, and the formed Cathorn, SO+, and PO+ reacted with O-2 in CRC to form CaO+, SO2+, and PO2+ to interfere with the determination of TiO+. We employed the mass shift reaction of H-2 and oxide ions to eliminate this interference. This method was evaluated using the human serum sample spike recovery experiment and comparative analysis by sector field (SF)-ICP-MS. The results showed that using reaction gas mixture O-2/H-2 reduced the background equivalent concentration (BEC) of Ti and improved sensitivity. The values determined by this method were consistent with the SF-ICP-MS values, which confirmed its accuracy and reliability. The limit of detection (LOD) of Ti was 0.78-7.20 ng L-1, the recovery was 96.0%-104%, and the relative standard deviation (RSD) was 2.0%-4.2%. This method has solved the problem that the determination of ultra-trace Ti in human serum cannot be accurately determined using O-2 reaction mode. It realizes the interference-free and highly sensitive determination of the ultra-trace Ti in samples with high levels of Ca, S, and P and provides a new technique for high-throughput and accurate determination of ultra-trace Ti in human serum. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

This study introduces a novel strategy for determining ultra-trace Ti in human serum using ICP-MS/MS, successfully eliminating interference and achieving high sensitivity. The proposed method was evaluated for accuracy and reliability through spike recovery experiments and comparative analysis, confirming its effectiveness for accurate determination of ultra-trace Ti in serum samples.