title: Sequential-pulse laser-induced breakdown spectroscopy of high-pressure bulk aqueous solutions.
abstract: Sequential-pulse (or dual-pulse) laser-induced breakdown spectroscopy (DP-LIBS) with an orthogonal spark orientation is described for elemental analysis of bulk aqueous solutions at pressures up to approximately 138 x 10(5) Pa (138 bar). The use of sequential laser pulses for excitation, when compared to single-pulse LIBS excitation (SP-LIBS), provides significant emission intensity enhancements for a wide range of elements in bulk solution and allows additional elements to be measured using LIBS. Our current investigations of high-pressure solutions reveal that increasing solution pressure leads to a significant decrease in DP-LIBS emission enhancements for all elements examined, such that we see little or no emission enhancements for pressures above 100 bar. Observed pressure effects on DP-LIBS enhancements are thought to result from pressure effects on the laser-induced bubble formed by the first laser pulse. These results provide insight into the feasibility and limitations of DP-LIBS for in situ multi-elemental detection in high-pressure aqueous environments like the deep ocean.
authors.affiliation: Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, USA.
authors.forename: Marion
authors.initials: M
authors.lastname: Lawrence-Snyder
authors.forename: Jon
authors.initials: J
authors.lastname: Scaffidi
authors.forename: S Michael
authors.initials: SM
authors.lastname: Angel
authors.forename: Anna P M
authors.initials: AP
authors.lastname: Michel
authors.forename: Alan D
authors.initials: AD
authors.lastname: Chave