Charles V. Banks

Bio: Charles V. Banks is an academic researcher from Iowa State University. The author has contributed to research in topics: Nickel & Hydrochloric acid. The author has an hindex of 23, co-authored 81 publications receiving 1381 citations.

Solvent microextraction into a single drop.

Abstract: An analytical technique is described which combines solvent extraction with gas chromatographic (GC) analysis in a simple and inexpensive apparatus involving very little solvent consumption. A small drop (8 μL) of a water-immiscible organic solvent, containing an internal standard, is located at the end of a Teflon rod which is immersed in a stirred aqueous sample solution. After the solution has been stirred for a prescribed period of time, the probe is withdrawn from the aqueous solution, and the organic phase is sampled with a microsyringe and injected into the GC for quantification. The observed rate of solvent extraction is in good agreement with a convective−diffusive kinetic model. Analytically, the relative standard deviation of the method is 1.7% for a 5.00-min extraction of the analyte 4-methylacetophenone into n-octane.

Contributions of organic peroxides to secondary aerosol formed from reactions of monoterpenes with O3.

Abstract: The role of organic peroxides in secondary organic aerosol (SOA) formation from reactions of monoterpenes with O3 was investigated in a series of environmental chamber experiments. Reactions were performed with endocyclic (α-pinene and Δ3-carene) and exocyclic (β-pinene and sabinene) alkenes in dry and humid air and in the presence of the OH radical scavengers: cyclohexane, 1-propanol, and formaldehyde. A thermal desorption particle beam mass spectrometer was used to probe the identity and volatility of SOA components, and an iodometric−spectrophotometric method was used to quantify organic peroxides. Thermal desorption profiles and mass spectra showed that the most volatile SOA components had vapor pressures similar to pinic acid and that much of the SOA consisted of less volatile species that were probably oligomeric compounds. Peroxide analyses indicated that the SOA was predominantly organic peroxides, providing evidence that the oligomers were mostly peroxyhemiacetals formed by heterogeneous reactio...