Gated and non-gated silver detection using microwave-assisted laser induced breakdown spectroscopy

The detection of silver using microwave-assisted laser induced breakdown spectroscopy (MW-LIBS) is demonstrated in solid and liquid samples at a 338.28 nm emission line. For solid sample analysis, the limit of detection (LoD) with a gated detector has been compared with that of a portable spectrometer with a non-gated detector. The LoD achieved by the gated and non-gated detectors are 4.5 ± 1.0 ppm and 7 ± 2.3 ppm, respectively. For aqueous silver, the LoD was found to be 385 ± 51 ppb. The LoD of MW-LIBS is more effective in liquid sample analysis than in solid sample analysis for atomic detection. The accuracy of the established calibration curve, based on the gated detector, has been verified to be ∼84%. For MW-LIBS, it was observed that relatively low laser energy is sufficient to develop a calibration curve and achieve an outstanding LoD.