Bromide and Doubly Charged Rare Earth Element Interferences in Collision Cell/Kinetic Energy Distribution Mode and Standard Mode Inductively Coupled Plasma Mass Spectrometry Analyses of Arsenic and Selenium

Oral Presentation

Prepared by T. White, E. Walton
USEPA Region 4 SESD, 980 College Station Road, Athens, GA, 30607, United States

Contact Information: [email protected]; 706-355-8817


Collision Cell/Kinetic Energy Distribution (KED) and standard mode Inductively Coupled Plasma Mass Spectrometry (ICP-MS) are complex analytical technologies with multielement capabilities, wide linear range, and low detection limits. Though ICP-MS offers many positive advantages, it is necessary that analysts are aware of the interference challenges that may occur. Many interferences are well documented and the ICP-MS spectroscopist is aware of the problems and solutions to the most common isobaric and polyatomic interferences. Though mentioned in analytical literature, bromide and doubly charged Rare Earth Element (REE) interferences on arsenic and selenium when analyzed by ICP-MS are not widely recognized. Bromide can contribute to a biased arsenic and selenium result when analyzed by standard mode ICP-MS and is present in a wide variety of environmental samples including seawater, drinking water, pesticides, pharmaceuticals, photography processes, flame retardants, and tissue. Interferences posed by certain doubly charged REEs can also contribute to a biased arsenic and selenium result when analyzed by standard and collision cell/KED mode ICP-MS. REEs are used in applications ranging from the automobile and petroleum industry, the glass industry, electronics, metallurgy, paint production, magnets, batteries, fertilizers, lasers, to the nuclear industry. The presence of either bromide or REEs in environmental samples is probable. Bromide and REEs, unlike some other interferences, become a significant interference problem at levels as low as 10-100 part per billion. It is crucial for the analyst to be aware of these interferences. If bromide and REEs are not monitored and corrected for erroneous results may be reported for arsenic and selenium. Interferences must be recognized and appropriate steps must be taken to deal with the analyses of arsenic and selenium that result in reliable data. This poster presentation will demonstrate the effect of bromide and REEs on arsenic and selenium when analyzed by standard mode and collision cell/KED ICP-MS.