title: Hydroxycarboxylic acid-derived organosulfates: synthesis, stability, and quantification in ambient aerosol.
abstract: Organosulfates have been proposed as contributors to aerosol growth and have been detected in both chamber and atmospheric aerosol samples. We present a simple method for the synthesis of quantitative analytical standards of two small hydroxycarboxylic acid-derived organosulfates, glycolic and lactic acid sulfate. Additionally, we discuss the stability of hydroxycarboxylic acid-derived organosulfates and their previously proposed sulfate hemiacetal isomers in commonly used solvents for filter extraction. The hydroxycarboxylic acid-derived organosulfates were found to be stable under acidic conditions comparable to those found in ambient aerosol. By using synthesized standards, quantitative organosulfate concentrations were measured from ambient particulate matter (PM(2.5)) collected in urban locations in the United States, Mexico City, and Pakistan. Lactic acid sulfate and glycolic acid sulfate concentrations ranged 0.4-3.8 ng/m(3) and 1.9-11.3 ng/m(3), respectively. We propose that glycolic acid sulfate represents an important tracer for atmospheric processes that form organosulfates in ambient particulate matter.
authors.affiliation: Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States.
authors.forename: Corey N
authors.initials: CN
authors.lastname: Olson
authors.forename: Melissa M
authors.initials: MM
authors.lastname: Galloway
authors.forename: Ge
authors.initials: G
authors.lastname: Yu
authors.forename: Curtis J
authors.initials: CJ
authors.lastname: Hedman
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Lockett
authors.forename: Tehshik
authors.initials: T
authors.lastname: Yoon
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Stone
authors.forename: Lloyd M
authors.initials: LM
authors.lastname: Smith
authors.forename: Frank N
authors.initials: FN
authors.lastname: Keutsch
mesh_terms: D000080:Acetals / Q000737:chemistry; D002244:Carbon / Q000032:analysis; D002264:Carboxylic Acids / Q000138:chemical synthesis* / Q000737:chemistry*; D002853:Chromatography, Liquid; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D052638:Particulate Matter / Q000032:analysis*; D012015:Reference Standards; D013431:Sulfates / Q000138:chemical synthesis* / Q000737:chemistry*
chemical_list: D000080:Acetals; D002264:Carboxylic Acids; D052638:Particulate Matter; D013431:Sulfates; D002244:Carbon