The first part of this two-part review focused on the fundamental and diagnostics aspects of laser-induced plasmas, only touching briefly upon concepts such as sensitivity and detection limits and largely omitting any discussion of the vast panorama of the practical applications of the technique. Clearly a true LIBS community has emerged, which promises to quicken the pace of LIBS developments, applications, and implementations. With this second part, a more applied flavor is taken, and its intended goal is summarizing the current state-of-the-art of analytical LIBS, providing a contemporary snapshot of LIBS applications, and highlighting new directions in laser-induced breakdown spectroscopy, such as novel approaches, instrumental developments, and advanced use of chemometric tools. More specifically, we discuss instrumental and analytical approaches (e.g., double- and multi-pulse LIBS to improve the sensitivity), calibration-free approaches, hyphenated approaches in which techniques such as Raman and fluorescence are coupled with LIBS to increase sensitivity and information power, resonantly enhanced LIBS approaches, signal processing and optimization (e.g., signal-to-noise analysis), and finally applications. An attempt is made to provide an updated view of the role played by LIBS in the various fields, with emphasis on applications considered to be unique. We finally try to assess where LIBS is going as an analytical field, where in our opinion it should go, and what should still be done for consolidating the technique as a mature method of chemical analysis.

https://journals.sagepub.com/doi/pdf/10.1366/11-06574

Laser-induced breakdown spectroscopy (LIBS), part II: review of instrumental and methodological approaches to material analysis and applications to different fields.

Statistics for analytical chemistry

Palladium and magnesium nitrates, a more universal modifier for graphite furnace atomic absorption spectrometry

The widespread use of silver nanoparticles (Ag-NPs) in consumer and medical products provides strong motivation for a careful assessment of their environmental and human health risks. Recent studies have shown that Ag-NPs released to the natural environment undergo profound chemical transformations that can affect silver bioavailability, toxicity, and risk. Less is known about Ag-NP chemical transformations in biological systems, though the medical literature clearly reports that chronic silver ingestion produces argyrial deposits consisting of silver-, sulfur-, and selenium-containing particulate phases. Here we show that Ag-NPs undergo a rich set of biochemical transformations, including accelerated oxidative dissolution in gastric acid, thiol binding and exchange, photoreduction of thiol- or protein-bound silver to secondary zerovalent Ag-NPs, and rapid reactions between silver surfaces and reduced selenium species. Selenide is also observed to rapidly exchange with sulfide in preformed Ag2S solid phas...

http://www.nseresearch.org/2012/posters/Jingyu_Liu_Zhongying_Want_Agnes_Kane_Robert_Hurt~Hurt_poster.pdf

Chemical transformations of nanosilver in biological environments.

Severe gross and microscopic lesions and other changes were found in adult aquatic birds and in embryos from Kesterson Reservoir (a portion of Kesterson National Wildlife Refuge), Merced County, Calif., during 1984. Adult birds from that area were emaciated, had subacute to extensive chronic hepatic lesions, and had excess fluid and fibrin in the peritoneal cavity. Biochemical changes in their livers included elevated glycogen and non-protein-bound sulfhydryl concentrations and glutathione peroxidase activity but lowered protein, total sulfhydryl, and protein-bound sulfhydryl concentrations. Congenital malformations observed grossly in embryos were often multiple and included anophthalmia, microphthalmia, abnormal beaks, amelia, micromelia, ectrodactyly, and hydrocephaly. Mean concentrations of selenium in livers (94.4 ppm, dry weight) and kidneys (96.6 ppm) of birds collected at the Kesterson ponds were about 10 times those found at a nearby control area (8.3 and 12.2 ppm). We conclude that selenium present in the agricultural drainage water supplied to the Kesterson ponds accumulated in the food chain of aquatic birds to toxic concentrations and caused the lesion and other changes observed.

Selenium toxicosis in wild aquatic birds.

Magnesium nitrate as a matrix modifier in the stabilized temperature platform furnace

Effect of graphite furnace substrate materials on analyses by furnace atomic absorption spectrometry

The presence of phosphate and iron provides a spectral interference for the determination of selenium at its primary resonance line at 196.0 nm that is avoided by using Zeeman background correction. Good quality pyrolytic graphite tubes, platform atomisation and integrated absorbance readings provide an acceptable quantitative environment for selenium and permit most analyses to be performed against a simple calibration graph using selenium in a nickel matrix modifier. Remaining problems appear to relate to loss of selenium prior to atomisation in the presence of certain matrices, notably the combination of sodium and sulphate. Charring in the presence of oxygen did not improve the analytical situation, nor did the use of silver, molybdenum or copper as a matrix modifier. We found a 2σ detection limit of 28 pg and a sensitivity of about 25 pg per 0.0044 As (A = absorbance units), expressed as characteristic amount. A preliminary direct method is presented for selenium in urine, with nickel, nitric acid and magnesium nitrate present, with a detection limit in urine of about 10 µg 1–1.

Determination of selenium in biological materials with platform furnace atomic-absorption spectroscopy and Zeeman background correction

The premature loss of analyte as a volatile halide is shown to be an important interference in some situations. When this char step interference is avoided, an interference in the atomization step can arise when large amounts of halide are present during that step. This atomization interference results from the binding of the analyte as a vapor phase metal halide, thereby preventing some portion of the analyte from absorbing atomic radiation. This vapor phase interference can be circumvented in several ways. The most convenient is the use of high concentrations of HNO/sub 3/ or H/sub 2/SO/sub 4/ which drives off more of the chloride as HCl during the dry and char steps. As much CaCl/sub 2/ in solution as 1 mg reduced the Mn signal in the presence of HNO/sub 3/ and Mg(NO/sub 3/)/sub 2/ by only 15%. Analogous experience was found with Tl. We believe the experience is quite general. The halide which interferes in the vapor phase is retained from the char step by adsorption or intercalation on the graphite tube. Thus we can expect still further improvements in the handling of large amounts of halide matrix when glassy carbon or solid pyroltic tubes become available.

Chloride interferences in graphite furnace atomic absorption spectrometry

Utilisation d'un injecteur automatique prototype d'echantillons sous forme de bouillie pour doser plomb, manganese, arsenic et fer dans des materiaux references et des sediments de riviere par spectrometrie GFAAS avec correction d'effet Zeeman

G. R. Carnrick

Papers

Magnesium nitrate as a matrix modifier in the stabilized temperature platform furnace

Effect of graphite furnace substrate materials on analyses by furnace atomic absorption spectrometry

Determination of selenium in biological materials with platform furnace atomic-absorption spectroscopy and Zeeman background correction

Chloride interferences in graphite furnace atomic absorption spectrometry

Automated slurry sample introduction for analysis of a river sediment by graphite furnace atomic absorption spectrometry