Studies of Laser Ablation ICP Atomic Emission Spectrometry using Laser Induced Plasma Emission Signals
| Authors | |
|---|---|
| Year of publication | 2004 |
| Type | Article in Periodical |
| Magazine / Source | ICP Information Newseltter |
| MU Faculty or unit | |
| Citation | |
| Field | Analytic chemistry |
| Keywords | LA-ICP-AES; LIBS; laser ablation |
| Description | In this work, the arrangement allowing simultaneously measuring LIB emission and LA ICP AES signals was developed. The system consisted of the Nd:YAG laser Quantel Brilliant operated at its fundamental wavelength of 1064 nm with a repetition rate 10 Hz. Sample was attached to a holder, which was a part of a laboratory-made ablation chamber. This holder was mounted on the computer controlled xy translation stages. Emission of breakdown plasma from chamber was collected by a fiber optic system and delivered onto an entrance slit of the TRIAX 320 monochromator. The monochromator was equipped with a photomultiplier Hamamatsu R928 gated by a laboratory-built control unit. The gate delay could be varied between 50 ns and 40 us with the gate width ranging from 5 ms to 25 us. Time resolved signal was recorded by the digital storage oscilloscope TDS1012. Sample aerosol from the ablation chamber was transported by carrier (surrounding) gas directly into the plasma torch of ICP spectrometer JY 170 Ultrace. The influence of argon, helium, nitrogen, oxygen and air on the laser-induced plasma and LA ICP AES signal of selected elements was investigated and compared for several types of metal samples. The higher LIB emission intensity was obtained in argon and the lower ones were found in helium, oxygen, nitrogen and air respectively. At longer times, the ion lines disappear while the neutral lines become stronger and then decay over a much longer period. The microplasma faster decay in helium than air or argon. There is an enhancement in ICP emission intensity for laser sampling in helium relative to argon for minor elements in steel, while for major elements (Cu(I) 324.754 nm in pure Cu target) were observed opposite effects. The ICP AES calibration curves are linear in a wide range, while LIBS calibration curves are in the same range non-linear. The stronger analyte lines may be used in lower concentration ranges, while the weaker lines may be used for higher concentration. |
| Related projects: |