This document presents a quantitative determination method for mercury in food using 7500i ICP-MS. Gold is added as a cleansing agent to avoid memory effects. The use of specific instrumental setup and measurement mode allows for rapid and accurate determination of trace mercury levels.
This document presents a method for the quantitative determination of mercury in foodstuffs using an Agilent 7500i ICP-MS. The procedure involves preparing microwave digests and analyzing them with gold added to standards, samples, and wash solutions to act as a cleansing agent and prevent memory effects.
The method utilizes the integrated sample introduction system (ISIS) in high sample throughput mode, a second vacuum pump, and a micro-flow concentric nebulizer. This setup allows for robust and rapid determination of mercury at parts per trillion (ppt) levels, achieving excellent agreement with certified reference materials and demonstrating system stability over 36-hour analytical runs.
| Plasma gas flow rate | 16 L/min |
|---|---|
| Carrier gas flow rate | 0.85 L/min |
| Make-up flow | 0.14 L/min |
| RF Power | 1400 Watts |
| Nebulizer | Agilent micro-flow 100 pL |
| Spray chamber temperature | Cooled to 2 °C |
| Sample tubing | 0.89 mm id |
| Internal standard tubing | 0.19 mm id |
| Analysis Speed (ISIS) | 0.10 rps |
The method uses a 7500i ICP-MS.
Gold is added offline to all standards, samples, and wash solutions to act as a cleansing agent.
Detection levels of between 10 and 30 ppt are routinely achieved.
The system stability was demonstrated over a 36-hour analytical run.