LA-ICP-MS (Laser Ablation Inductively Couple Plasma Mass Spectrometry) is a powerful analytical technology that enables highly sensitive elemental and isotopic analysis to be performed directly on solid samples.
LA-ICP-MS begins with a laser beam focused on the sample surface to generate fine particles – a process known as Laser Ablation. The ablated particles are then transported to the secondary excitation source of the ICP-MS instrument for digestion and ionisation of the sampled mass. The excited ions in the plasma torch are subsequently introduced to a mass spectrometer detector for both elemental and isotopic analysis.
Benefits of LA-ICP-MS
LA-ICP-MS is one of the most exciting analytical technologies available because it can perform ultra-highly sensitive chemical analysis down to ppb (parts per billion) level – without any sample preparation.
Samples can be both conducting or non-conducting, and the analysis can be performed in the air without the need for a complex vacuum system. Results are available within seconds and therefore LA-ICP-MS delivers that fastest analysis speed of all analytical techniques with the limit of detection approaching ppb level.
The sample mass size required for LA-ICP-MS analysis is sub-microscale – pictograms to femtograms. Traditional liquid nebulisation approaches for ICP-MS require the removal of milligrams of sample mass in order to be effective.
When applied with optimised laser ablation conditions and ICP-MS data acquisition protocols, LA-ICP-MS allows versatile solid sampling schemes that include:
- Bulk Analysis
- Local Inclusion and Defect Analysis
- Depth Profiling
- Elemental / Isotope Mapping
The two most commonly used laser-based methods are bulk analysis with a typical laser spot size of 100-350µm and microanalysis with the laser spot size as small as a few microns.
Femtosecond Laser Pulsing
The use of femtosecond laser pulsing represents the latest technical advance in LA-ICP-MS technology. It improves precision and accuracy, reduces the elemental/isotopic fractionation and enhances the sensitivity of the measurements. Many researchers have shown that the femtosecond laser pulsing brings these benefits to LA-ICP-MS analysis:
- Non-thermal mass ablation such as Coulomb explosion and direct chemical bond breaking that represents true chemistry of the sample and is conducive in reducing the elemental/isotopic fractionation.
- An ideal size distribution (20 – 200 nm) of the ablated particles that are readily transported to the ICP-MS plasma torch that result in the increased detection sensitivity.
- More consistent size distribution of the ablated particles that decrease the fluctuations in the transient ICP-MS signal and increase measurement precision.
- Complete digestion of the transported particles and reduction of fractionation in the secondary excitation source of the ICP-MS instrument
Applied Spectra’s J200 Femtosecond LA Instrument
Applied Spectra harnesses LIBS technology with its state-of-the-art elemental testing devices. We deliver their solutions to the UK and Ireland which are fast, reliable, precise and environmentally friendly. Our instruments are adaptable to a variety of environments, from field testing, to manufacturing floors, to laboratory settings. Contact DSL to learn more.