Laser-induced breakdown spectroscopy applied on low-alloyed zinc samples

The use of laser-induced breakdown spectroscopy for chemical analysis in the single-shot regime has been investigated for low-alloyed zinc samples. Several parameters that are important for plasma formation has been investigated and their importance for accurate and precise single-shot measurements are discussed. The standard deviation is compared for measurements performed on a day-to-day basis during four days and for a measurement series consisting of five measurements in one day. It was found that the spread is not larger for a measurement series performed on a single day compared to day-to-day basis. The influence of local spatial inhomogeneities of the alloy elements in the sample concentrations is discussed in this context and the reference samples have been investigated with a scanning electron microscopy and light optical microscopy to verify this. It is found that the relative standard deviation of the signal depends to large extent on the sample homogeneity at low concentrations. The importance of spatial averaging for LIBS when doing calibrations is established in this case. The relative error for single-shot measurements will depend on the slope of the analytical curve and increase at lower concentrations.