title: Use of SEC-ICP-MS with a collision cell for determining the interaction of chromium with DNA extracted from metal-contaminated soils.
abstract: The potential of chromium to bind to DNA isolated directly from soil microbial communities was investigated in this study. An analytical scheme was developed to distinguish between chromium bound to DNA and its fragments or chromium contained elsewhere in an environmental DNA extract. DNA was extracted from chromium-contaminated soils and purified using DNA clean-up resins. Size-exclusion chromatography was employed due to its advantages in the separation and molecular weight approximation of large biomolecules. It was coupled with two on-line detection systems (spectrophotometric and inductively coupled plasma mass spectrometric) to study the binding of chromium to DNA or other components in a DNA extract. A collision cell was pressurized with helium to remove diatomic and polyatomic interferents resulting from the chosen mobile phase. Chromium peaks were observed in both the large and small molecular weight regions of the chromatogram; to further confirm that the environmentally extracted DNA contained Cr, the subsequently purified DNA was examined for total Cr using flow injection ICP-MS to accommodate small sample volumes. DNA samples isolated from the two soils examined contained 0.5-0.7 ppb Cr, indicating that DNA isolated directly from a chromium-contaminated soil has chromium bound to the nucleic acids.
authors.affiliation: Department of Biological Sciences, University of Cincinnati, Cincinnati, OH 45221-0006, USA. smspitz@uwm.edu
authors.forename: Sabrina R
authors.initials: SR
authors.lastname: Mueller-Spitz
authors.forename: Anne P
authors.initials: AP
authors.lastname: Vonderheide
authors.forename: Jodi R
authors.initials: JR
authors.lastname: Shann
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Caruso
authors.forename: Brian K
authors.initials: BK
authors.lastname: Kinkle
mesh_terms: D002850:Chromatography, Gel / Q000379:methods*; D002857:Chromium / Q000032:analysis* / Q000737:chemistry; D004247:DNA / Q000032:analysis* / Q000737:chemistry; D004784:Environmental Monitoring / Q000295:instrumentation; D013058:Mass Spectrometry / Q000295:instrumentation* / Q000379:methods*; D010316:Particle Size; D012989:Soil Pollutants / Q000737:chemistry*; D013997:Time Factors
chemical_list: D012989:Soil Pollutants; D002857:Chromium; D004247:DNA