Diode Laser Spectroscopic Monitoring of Trace Gases*Update based on original article by Frank K. Tittel and Konstantin P. Petrov, Encyclopedia of Analytical Chemistry, © 2000, John Wiley & Sons Ltd.

Abstract

Modern diode laser spectroscopy is becoming an important and a more widely used tool for detection and measurement of trace gases. The change is driven by the recent advances in diode laser technology and diode laser frequency conversion techniques, which now push the limits of emission wavelength, output power, operating temperature, miniaturization, and cost. Basic features of the diode laser now find new, interesting, and unique use in well‐established laboratory and field applications related to trace‐gas detection and, in some instances, even transform the traditional spectroscopic methods. It is the purpose of this chapter to familiarize the reader with the key elements of diode laser technology and analytical methods used in diode laser spectroscopy.

A validated analytical method to measure metals dissolved in deep eutectic solvents

“…34 In our study, the detection and quantification of metals dissolved in DES were evaluated considering the International Council for Harmonization (ICH) guidelines, 35 AOAC International (AOAC), 36 the International Union of Pure and Applied Chemistry (IUPAC), 42 the protocol for the validation of an analytical method in chemistry by the Centre of expertise in environmental analysis of Québec, 37 as well peer-reviewed literature. 34,37–39 The validation parameters considered in our work included linearity, limits of detection and quantification, accuracy, precision, and selectivity (Fig. 1C).…”

“…There are several methods available to estimate the LOD and LOQ, which correspond to the lowest concentration of analyte that can be consistently detected and the lowest concentration of analyte that can be detected consistently and accurately, respectively. 33,34,38,44 In this work, LOD and LOQ values for each metal were estimated mathematically from the slope of linear calibration curve (slope m ) and the standard deviation of the response ( i.e. , positive intensity) of ten blank solutions ( σ blank ) (Eqn (1) and (2)).…”

“…Accuracy values between 90% to 110% were considered acceptable. 32,33,38 The method's random error was estimated by considering both intra- and inter-run precision. Intra-run precision, namely the repeatability of the method, was expressed as the relative standard deviation (RSD) and was the standard deviation over the mean value for four runs of the 2, 3, and 5 μg mL −1 samples for each metal.…”

Direct Absorption and Photoacoustic Spectroscopy for Gas Sensing and Analysis: A Critical Review

“…[ 34–38 ] On the other hand, the linewidth of gases is a few $${\rm{GHz}}$$ at atmospheric pressure, [ 32,35,39–41 ] while at reduced pressure linewidths can reach tenths of $${\rm{MHz}}$$. [ 42,43 ] Thus, the laser linewidth is much smaller than the gas linewidth.…”

Research on the high indium content InGaAs multiple quantum wells wafers for λ>1.55μm laser diodes

“…Laser diodes, which emit light with wavelengths k > 1.55 lm, have been developed quickly in recent years as they are attractive for applications in gas monitoring application [1], remote sensing [2], pollutant detection [3], molecular spectroscopy [4], ''eye-safe'' illuminators and medical applications [5]. Moreover, high power individual laser diodes and/or arrays emitting between 1.8-2.1 lm can be an effective and convenient optical pumping source for both semiconductor and solid-state middle infrared light-emitting devices [6].…”