Direct analysis of bromine and iodine in dried serum spots by laser ablation inductively coupled plasma mass spectrometry

• Published in: Rapid communications in mass spectrometry Vol. 34; no. 4; pp. e8591 - n/a
• Main Authors: He, Jing, Li, A‐Fang, Han, Hua‐yun, Su, Shuang, Zhang, Pei, Zhang, Er‐peng
• Format: Journal Article
• Language: English
• Published: England Wiley Subscription Services, Inc 28-02-2020
• Subjects: Biological properties; Bromine; Calibration; Condition monitoring; Emission spectroscopy; Inductively coupled plasma mass spectrometry; Iodine; Laser ablation; Laser beams; Lasers; Mass spectrometry; Matching; Neodymium lasers; Pretreatment; Raster scanning; Scientific imaging; Semiconductor lasers; Statistical analysis; Statistical methods; YAG lasers
• ISSN: 0951-4198; 1097-0231
• DOI: 10.1002/rcm.8591

Rationale
Accurate quantitative analysis of bromine and iodine in serum is an important aspect of monitoring body condition, but the volatile loss of halogen in sample pretreatment is a troublesome problem. We present a validated and flexible high‐throughput method for quantification of bromine and iodine in dried serum spots (DSS) using laser ablation inductively coupled plasma mass spectrometry (LA‐ICP‐MS) and an external aqueous standard calibration curve. The influence of serum matrix and laser ablation (LA) conditions on the analysis of bromine and iodine in DSS was researched systematically.
Methods
Aqueous standards without matrix matching were used for calibration to analyze bromine and iodine in serum by LA‐ICP‐MS. 5‐μL volumes of the aqueous standard solution and serum samples in 10 times diluted concentration were deposited on the PTFE paper to form dried standard calibration spots (DSCS) and DSS, of less than 2 mm in diameter. LA was performed using a focused Nd:YAG laser beam in raster lineal scan mode.
Results
The limits of detection (LODs) for bromine and iodine in DSS were 0.23 and 0.03 mg L−1, respectively. The relative standard deviation (RSD) for this method was less than 10%. The samples were also detected with matrix matching calibration by ICP‐MS. The accuracy of the method was verified by statistical analysis of these results from ICP‐MS and LA‐ICP‐MS. The accuracy is satisfactory with recoveries ranging from 81.5% to 118%.
Conclusions
A novel and simple approach for high‐throughput screening of bromine and iodine in DSS has been established by LA‐ICP‐MS. Calibration could be achieved using an aqueous standard solution instead of a matrix‐matching solution. The method allowed analysis of low‐volume biological samples without derivatization and decreased the risk of contamination or loss.