Multielement analysis of micro-volume biological samples by ICP-MS with highly efficient sample introduction system

Area of Science:

• Analytical Chemistry
• Mass Spectrometry
• Biotechnology

Background:

• Inductively coupled plasma mass spectrometry (ICP-MS) is a powerful technique for elemental analysis.
• Analyzing micro-volume biological samples presents challenges due to limited sample availability.
• Existing sample introduction systems often require larger sample volumes and have lower throughput.

Purpose of the Study:

• To develop and validate a highly efficient sample introduction system for ICP-MS.
• To enable accurate multielement analysis of micro-volume biological samples.
• To improve sample throughput and reduce sample consumption.

Main Methods:

• A novel sample introduction system combining an inert loop injection unit and a high-performance concentric nebulizer (HPCN) with a temperature-controlled cyclone chamber was designed.
• The system was optimized for low liquid flow rates (10 μL min⁻¹).
• The system's performance was validated using NIST SRM 1577b Bovine Liver and an Escherichia coli sample.

Main Results:

• The system achieved stable signals for extended periods (100s) with minimal sample dilution (20 μL sample).
• The HPCN with a heated cyclone chamber (60°C) provided sensitivity comparable to conventional systems using 1 mL min⁻¹ flow rates, but with a two-orders-of-magnitude lower sample consumption rate.
• Accurate multielement analysis was demonstrated for 12 elements in bovine liver and 14 elements in E. coli samples.

Conclusions:

• The proposed sample introduction system is highly effective for multielement analysis of micro-volume biological samples.
• It offers significant advantages in terms of sensitivity, sample consumption, and throughput.
• This method is particularly valuable when dealing with limited biological sample quantities.