This article describes how to improve sample throughput for ICP-OES oil analysis by improving the sample introduction system. By using a novel pump tubing arrangement, analysis time can be significantly reduced.
The document details an optimization method for Inductively Coupled Plasma-Optical Emission Spectrometers (ICP-OES) specifically for analyzing wear metals in lubricating oils. The primary goal is to increase sample throughput by reducing the time required for sample introduction and washout, which are often the bottlenecks in analysis speed.
The proposed solution involves a novel pump tubing arrangement using an additional peristaltic pump tube connected via a T-piece. This setup directs excess sample flow to waste while maintaining high flow rates to the nebulizer, reducing sample uptake time by approximately 10 seconds and washout times significantly. The note provides specific instrument operating conditions, detection limits for various elements in kerosene, maximum measurable concentrations, and data demonstrating long-term stability over an eight-hour period.
| Plasma gas flow | 15.0 L/min |
|---|---|
| Auxiliary gas flow | 2.25 L/min |
| Nebulizer pressure or flow | 110 kPa or 0.60 L/min |
| Viewing height | 10mm |
| Pump speed | 12 rpm |
| Sample uptake delay | 15s |
| Stabilization time | 5s |
| Rinse time | 10s |
Using the modified setup, the sample uptake time was decreased by approximately 10 seconds.
It is possible to accurately determine key wear metals and other elements in less than 50 seconds per sample.