Evaluating Various Sample Preparation Procedures on Biological Samples for Analysis by ICP-MS

Andrew Ryan, Applications, Analytik Jena, Jena, Germany
Rui Santos, Applications, Analytik Jena, Jena, Germany

Presented will be the comparison of three sample preparation procedures on biological samples including whole blood, blood plasma, serum and urine for multi-element analysis by ICP-MS. The three preparations consist of 1) complete dissolution by microwave digestion 2) dilution in an acidic medium 3) dilution in an alkali medium. The advantages of nitrogen gas addition to the ICP for As and Se will also be discussed, with both signal enhancement and reduced matrix effects being observed. Nitrogen gas addition was found to be an effective alternative to the traditional addition of propanol or butanol to clinical samples in buffering the known enhancing effects of variable carbon content on As and Se.

Following the analysis of various certified reference materials, the alkali sample preparation technique was shown to provide the greatest accuracy for a broader range of elements by ICP-MS, including iodine. Lower recovery for Cu and Zn was also observed using acid dilution suggesting the elements were not fully released from the coagulated biological material. Microwave digestion and alkali dilution provide complete dissolution of biological material.