Surface Analysis Using Laser Ablation with ICP-OES

7 Surface Analysis Using Laser Ablation with ICP-OES 

Laser ablation can be carried out on any material without special sample preparation. The laser beam can be directed onto a defined spot of the sample or moved to different parts to analyse over a defined area. It can be moved in an XYZ plane using a stepper motor and driven in translational motions on which the cell is mounted and with more expensive models can be turned for analysis in other parts of the sample. Lasers can operate in UV, visible, and IR regions of the spectrum and a recent development in laser technology uses neodymium yttrium aluminium garnet (Nd YAG) which gives high repetition rate at a comparatively low power. This method of analysis is suited to bulk analysis of solid materials and the amount of volatility varies from sample to sample. The size of the laser spot can vary from 10 to 250 pm and little or no sample preparation is required. Errors are greatly reduced because of the simple sample preparation, and the fact that no solvents are required reduces interferences. 

Detection limits can be as low as 2.0 ng to 100 ng depending on the sample and ease of etching because the sample measured is 100% not diluted. It can be used as a semi-quantitative analyser but is difficult to quantify due to lack of available standards. However, for certain samples it may be possible to carry out quantitative analysis if special solids standards are prepared containing increasing concentrations of metals blended into similar blank samples under tests. In such cases the unknown sample and standard blends must be ablated under identical conditions. 

ICP Laser Computer Computer Controlled 200m Camera 

The power of laser ablation can be extended as a popular method for trace and bulk analysis in conjunction with ICP-OES and is an invaluable tool in the study of surface behaviour particularly where sensitive surfaces are important. The common area for surface knowledge is in environment, medicines, adhesives, powders, slurries, oil-based samples and liquids. It finds application in the analysis of metallurgical samples, non-conductive polymers, ceramic materials, surface mapping, elemental migration, depth profiling, thin film coatings, biological and clinical specimens, forensic, paint chips, inks, bullets, fabrics, etc. 

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