LIBS Info: Element Analysis
| Title | Authors | Material | Detector | Spectrometer | Software |
|---|---|---|---|---|---|
| Direct spectral analysis of tea samples using 266 nm UV pulsed laserinduced breakdown spectroscopy and cross validation of LIBS results with ICP-MS | L.E. Oloore, Umair Baig, Yusuf B. Habibullah, M.A. Gondal | Organic | Andor iStar ICCD | Andor Shamrock 500i | |
| Laser: | Nd:YAG 266.0000nm 17.5000mJ 20.000Hz |
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| Gate Delay: | 0.317us | ||||
| Gate Width: | Noneus | ||||
| Pellets were made by compressing supermarket tea at high pressure. These were analysed, with comparison to ICP-MS analysis of liquid teas. The authors ensured the LIBS analysis was undertaken under conditions of Local Thermodynamic Equilibrium by measuring the plasma temperature (Boltzmann plot) and electron density (Stark Broadening). Similarly delay time was optimised for best S/N ratio. Note LOD in the paper quote 2 sigma/S. These have been converted to the more standard 3 sigma/S for display | |||||
| Element | Detection Limit (ppm) | Wavelength (nm) | Other Wavelengths (nm) | Calibration Method | Calibration Range (ppm) | Notes |
|---|---|---|---|---|---|---|
| Ca | 18.0000 (Calibration Curve Slope) | 317.9000 | N/A | Univariate | -10.0000--10.0000 | Analysis of pellets made of tea. |
| Si | 1.5000 (Calibration Curve Slope) | 784.9000 | N/A | Univariate | -10.0000--10.0000 | Analysis of pellets made of tea. |
| Cu | 9.0000 (Calibration Curve Slope) | 777.9000 | N/A | Univariate | -10.0000--10.0000 | Analysis of pellets made of tea. |
| Br | 16.5000 (Calibration Curve Slope) | 793.9000 | N/A | Univariate | -10.0000--10.0000 | Analysis of pellets made of tea. |
| K | 21.0000 (Calibration Curve Slope) | 766.5000 | N/A | Univariate | -10.0000--10.0000 | Analysis of pellets made of tea. |
| Cr | 18.0000 (Calibration Curve Slope) | 286.5000 | N/A | Univariate | -10.0000--10.0000 | Analysis of pellets made of tea. |
| Fe | 33.0000 (Calibration Curve Slope) | 275.6000 | N/A | Univariate | -10.0000--10.0000 | Analysis of pellets made of tea. |
| Element | RMSE (ppm) | Wavelength (nm) | Calibration Method | Notes |
|---|---|---|---|---|
| Br | 90.0999 ppm | 793.9000 | Univariate Calibration | . . . . . . |
| Cu | 3.0000 ppm | 777.9000 | Univariate Calibration | Analysis of pellets made of tea. . . . . . |
| Fe | 37.8968 ppm | 275.6000 | Univariate Calibration | Analysis of pellets made of tea. . . . . . |
| Cr | 11.2472 ppm | -286.5000 | Univariate Calibration | . . . . . . |
| Ca | 6.9041 ppm | 317.9000 | Univariate Calibration | . . . . . . |
| K | 310.3415 ppm | 766.5000 | Univariate Calibration | . . . . . . |
| Si | 1.5275 ppm | 784.9000 | Univariate Calibration | . . . . . . |