This document describes the determination of 21 elements in an oil sample by ICP-OES.
The document details a method for analyzing trace metals in lubricating oil to diagnose engine wear and contamination. It utilizes Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-OES) on an Agilent Liberty 100 instrument, featuring specific operating parameters optimized for organic solvents like kerosene.
The procedure involves a simple 1/10 weight/volume dilution of the oil sample with kerosene. The note provides detailed instrumental conditions, including gas flow rates and nebulizer pressure settings required to minimize carbon buildup when analyzing organics. It also lists detection limits for 21 specific elements and reports spike recovery percentages ranging from 92% to 104%, demonstrating the method's accuracy.
| RF Generator Frequency | 40.68 MHz |
|---|---|
| Monochromator Type | 0.75 m Czerny-Turner |
| Grating Specification | 1800 grooves/mm Holographic grating |
| Optical Resolution (1st order) | 0.018 nm |
| Plasma Gas Flow Rate | 12.0 L/min |
| Auxiliary Gas Flow Rate | 2.25 L/min |
| Torch Type | Standard one piece quartz torch with 1.4mm id injector tube |
| Nebulizer Pressure | 120 kPa |
| Pump Rate | 15 rpm |
| Sample Uptake Rate | 1.1 mL/min |
| Integration Time | 3 sec |
| PMT Voltage | 650 V |
Kerosene is commonly used, along with Xylene, DIBK, MIBK, or White spirit.
The dilution method is only applicable for wear metal particles up to 5 um.
The percentage spike recoveries ranged from 92% to 104%.