Determination of lead in Jamu by laser-induced breakdown spectroscopy

Jamu is Indonesian traditional herbal medicine that is still consumed nowadays to treat a variety of medical conditions. Jamu contaminated with toxic heavy metals such as lead, a common environmental pollutant, can cause various health issues even in trace concentrations. This study evaluated a technique for determining lead contents in jamu utilizing laser-induced breakdown spectroscopy (LIBS). A Q-switched Nd:YAG laser at a wavelength of 355 nm, with a pulse duration of 10 ns, and maximum pulse energy of 15 mJ, was used for plasma generation on the sample surface under atmospheric pressure. The lead spectral intensity in plasma emission spectra was correlated with the lead concentration using a linear regression model. The actual concentrations and projected values produced by the model showed good agreement with the R2 of the model was 0.998. The detection limit obtained from the model was 99.38 ppm. These results indicated that laser-induced breakdown spectroscopy could quickly and accurately identify heavy metals in Indonesian traditional medicine.