Editing Atomic absorption spectroscopy (section)

====Specialized atomization techniques====
While flame and electrothermal vaporizers are the most common atomization techniques, several other atomization methods are utilized for specialized use.<ref>{{Cite web|url=https://chem.libretexts.org/Textbook_Maps/Analytical_Chemistry_Textbook_Maps/Map%3A_Analytical_Chemistry_2.0_(Harvey)/10_Spectroscopic_Methods/10.4%3A_Atomic_Absorption_Spectroscopy|title=Atomic Absorption Spectroscopy|last=Harvey|first=David|date=2016-05-25|website=chem.libretexts.org|access-date=2017-10-06|archive-url=https://web.archive.org/web/20171006113153/https://chem.libretexts.org/Textbook_Maps/Analytical_Chemistry_Textbook_Maps/Map%3A_Analytical_Chemistry_2.0_(Harvey)/10_Spectroscopic_Methods/10.4%3A_Atomic_Absorption_Spectroscopy|archive-date=2017-10-06|url-status=dead}}</ref><ref>{{Cite web|url=http://blogs.maryville.edu/aas/atomization-source/|title=Sample Atomization – Atomic Absorption Spectroscopy Learning Module|website=blogs.maryville.edu|language=en-US|access-date=2017-11-02}}</ref>

=====Glow-discharge atomization=====
A glow-discharge device (GD) serves as a versatile source, as it can simultaneously introduce and atomize the sample. The [[glow discharge]] occurs in a low-pressure argon gas atmosphere between 1 and 10 torr. In this atmosphere lies a pair of electrodes applying a [[Direct Current|DC]] voltage of 250 to 1000 V to break down the argon gas into positively charged ions and electrons. These ions, under the influence of the electric field, are accelerated into the cathode surface containing the sample, bombarding the sample and causing neutral sample atom ejection through the process known as [[sputtering]]. The atomic vapor produced by this discharge is composed of ions, ground state atoms, and a fraction of excited atoms. When the excited atoms relax back into their ground state, a low-intensity glow is emitted, giving the technique its name.

The requirement for samples of glow discharge atomizers is that they are electrical conductors. Consequently, atomizers are most commonly used in the analysis of metals and other conducting samples. However, with proper modifications, it can be utilized to analyze liquid samples as well as nonconducting materials by mixing them with a conductor (e.g. graphite).

=====Hydride atomization=====
Hydride generation techniques are specialized in solutions of specific elements. The technique provides a means of introducing samples containing arsenic, antimony, selenium, bismuth, and lead into an atomizer in the gas phase. With these elements, hydride atomization enhances detection limits by a factor of 10 to 100 compared to alternative methods. Hydride generation occurs by adding an acidified aqueous solution of the sample to a 1% aqueous solution of sodium borohydride, all of which is contained in a glass vessel. The volatile hydride generated by the reaction that occurs is swept into the atomization chamber by an inert gas, where it undergoes decomposition. This process forms an atomized form of the analyte, which can then be measured by absorption or emission spectrometry.

=====Cold-vapor atomization=====
The cold-vapor technique is an atomization method limited only for the determination of mercury due to it being the only metallic element to have a large vapor pressure at ambient temperature.{{citation needed|date=March 2016}} Because of this, it has an important use in determining organic mercury compounds in samples and their distribution in the environment. The method initiates by converting mercury into Hg<sup>2+</sup> by oxidation from nitric and sulfuric acids, followed by a reduction of Hg<sup>2+</sup> with [[SnCl2|tin(II) chloride]]. The mercury is then swept into a long-pass absorption tube by bubbling a stream of inert gas through the reaction mixture. The concentration is determined by measuring the absorbance of this gas at 253.7&nbsp;nm. Detection limits for this technique are in the parts-per-billion range, making it an excellent mercury detection atomization method.