A review of normalization techniques in analytical atomic spectrometry with laser sampling: From single to multivariate correction

Double-Pulse Remote Laser-Induced Breakdown Spectroscopy Analysis of Magnesium Alloys

“…However, the lower sensitivity and precision than the other elemental analysis methods is one of the major drawbacks especially in remote detection [2]. To improve LIBS, a lot of approaches have been proposed to enhance the analytical performance [3][4][5][6], and the double pulse LIBS (DP-LIBS) has been demonstrated by a number of studies [7][8][9][10][11], which is a very efficient approach for enhancing the intensity of plasma emission and improvement of the analytical capabilities of LIBS.…”

Normalization of laser-induced breakdown spectroscopy spectra using a plastic optical fiber light collector and acoustic sensor device

“…In order to mitigate this problem, several techniques like calibration-free LIBS [10] or normalization procedures have been proposed [11]. One simple possibility is so-called internal standardization, already discussed in the very first paper proposing the LIBS technique [12].…”

“…This solution is based on the intensity of the emission line of the element to be quantified being divided by the intensity of a weak spectral line of another element whose concentration is known or at least is constant among samples, as this ratio has been found to vary to a much lesser extent than the absolute intensity. However, not all pairs of lines are suitable candidates, as they must satisfy certain spectroscopic criteria: pairs with similar excitation potential, intensity differences smaller than 10 times, and spectral proximity have provided good results [11]. Therefore, depending on the sample, it is not always possible to find suitable lines for this internal standardization within the captured spectral range.…”

“…One possibility is the acoustic wave generated by the plasma, as the laser pulse produces rapid vaporization of the material surface, and the expansion of the ablated vapor into the surrounding gas forms a shockwave that generates a sound. Although some works have found a complex relationship between the vaporized mass and the laser irradiance for large irradiance values due to the plasma shield effect [13], it is generally assumed that the intensity of the acoustic wave is linearly related to the laser irradiance, and therefore, it is a valid signal for normalization purposes [4,11,14,15]. Acoustic emission is usually detected with standard microphones in the human acoustic detection range, allowing measurement of the acoustic signal from distances up to several meters from the target.…”

Analitikai módszerek fejlesztése folyadék és szilárd minták LIBS vizsgálatára

“…Kísérleteikben a mangán intenzitása és a tranziens akusztikus jel első csúcsa között jó korrelációt figyeltek meg. További referencia jelként szolgál a háttér teljes emissziója, az elektromos áram, a plazma hőmérséklete, az elektronsűrűség, a lézer impulzusenergiája, a teljes integrált emisszió és a Mie-szórás is [43]. Napjainkban az is előfordul, hogy jelnormalizációhoz nem ezeket az egyszerű, egy referencia értéken alapuló módszereket használják, hanem többváltozós módszereket.…”