Dean Larry Duval
Procter & Gamble
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Publication
Featured researches published by Dean Larry Duval.
Journal of Analytical and Applied Pyrolysis | 1998
Toshihiko Uchiyama; Akihiko Kawauchi; Dean Larry Duval
Abstract This report summarizes method development for the simultaneous identification of dye transfer inhibitors (DTIs) using pyrolysis-gas chromatography with mass detection (Py-GC/MS). Ground detergent products are directly pyrolyzed and pyrolysis fragments introduced into a GC column. Key fragments separated via GC are detected by selected ion monitoring (SIM) to achieve the high sensitivity and selectivity necessary to measure markers of DTIs in the presence of high levels of surfactant by products. Trace levels of DTIs, poly- N -vinylpyrrolidone (PVP), copolymer of N -vinylpyrrolidone and N -vinylimidazole (PVPVI), and poly-4-vinylpyridine- N -oxide (PVNO) in laundry detergent products were quickly identified. Detection limits were 0.05% for PVP and 0.1% for PVPVI and PVNO.
Journal of the American Oil Chemists' Society | 1996
I. Ogura; Dean Larry Duval; Shoji Kawakami; Koichiro Miyajima
Current approaches for identifying and quantitating surfactants in various product matrices require the use of wet chemical, chromatographic, and spectroscopic techniques. The primary objective of this work is to replace current multiple-technique approaches for identifying surfactants and quantitating their homologue distribution with a single rapid technique. To meet this objective, a simple preparation procedure has been developed to prepare consumer product samples for subsequent analysis by ion-spray mass spectrometry. Quantitation of linear alkylbenzene sulfonates in detergents with this technique is demonstrated.
Journal of the American Oil Chemists' Society | 1995
I. Ogura; Dean Larry Duval; Koichiro Miyajima
A method has been developed for the identification of unknown brighteners in detergents by a high-performance liquid chromatography (HPLC)/mass spectrometry (MS)/ultraviolet (UV)/fluorescence system with MS/MS capability. Ten brighteners from five groups—stilbene, biphenyl stilbene, pyrazoline, oxazole, and coumarin derivatives—were separated on a C8 reverse-phase HPLC column. The UV and fluorescence detectors positively located the brightener peaks and differentiated betweentrans andcis isomers separated by the chromatographic system. Ion-spray (IS)/MS and IS/MS/MS spectra were then used to identify the structure of unknown brighteners in detergent products. An HPLC with a diode-array detector provided a quick identification check and accurate quantitative data for known brighteners, even on overlapping peaks.
Archive | 2003
Christian Gerhard Friedrich Gerlach; Bradford Scott Barron; Dean Larry Duval; Eugene Joseph Pancheri; Mary Jane Combs; Paul Eugene Rienzo
Archive | 2001
Hirotaka Uchiyama; Janese Christine O'brien Stickney; Jonathan Robert Cetti; Ricky Ah-Man Woo; Dean Larry Duval; Gayle Marie Frankenbach
Archive | 2004
Shulin Larry Zhang; Trace Wendell De Guzman Trajano; Kofi Ofosu-Asante; Joseph Dean Heatherly; Freddy Arthur Barnabas; Jamie Marie Childers; Cynthia Maria Bedell; Dean Larry Duval; Joia Kirin Spooner-Wyman
Archive | 2003
Bradford Scott Barron; Mary Jane Combs; Dean Larry Duval; Keith David Fanta; Christian Gerhard Friedrich Gerlach; Laura Lynn Heilman; Eugene Joseph Pancheri; Paul Joseph Russo; Christopher Lawrence Smith; Pedro Vincent Vandecappelle
Archive | 2000
Ricky Ah-Man Woo; Dean Larry Duval; Daniel Scott Cobb; Robert William Kiblinger; Hirotaka Uchiyama; Toan Trinh
Archive | 2003
Ricky Ah-Man Woo; Dean Larry Duval; Kristin Marie Nichols; Steven Reece; Robert William Kiblinger; Daniel Scott Cobb; Hirotaka Uchiyama
Archive | 2001
Hirotaka Uchiyama; Ricky Ah-Man Woo; Dean Larry Duval; Steven Reece