EVALUATION OF PRIMARY PHOTOPRODUCT QUANTUM YIELDS IN FULVIC-ACID

被引：62

作者：

BRUCCOLERI, A ^{[1
]}

PANT, BC ^{[1
]}

SHARMA, DK ^{[1
]}

LANGFORD, CH ^{[1
]}

机构：

[1] CONCORDIA UNIV, DEPT CHEM, MONTREAL H3G 1M8, QUEBEC, CANADA

来源：

ENVIRONMENTAL SCIENCE & TECHNOLOGY | 1993年 / 27卷 / 05期

关键词：

D O I：

10.1021/es00042a011

中图分类号：

X [环境科学、安全科学];

学科分类号：

08 ; 0830 ;

摘要：

Time-resolved photoacoustic spectroscopy in conjunction with magnetic circular dichroism (MCD) spectroscopy has been applied to determine energies and quantum yields for the formation of triplet states in aqueous solutions of two well-characterized (Laurentian and Armadale) fulvic acids. For the Laurentian sample, intersystem, crossing quantum yields range from 0.79 to 0.28 for the pH range 2.0-9.5. The average triplet energy is estimated as 1.8 X 10(2) kJ mol-1 from MCD spectra. For the Armadale sample, intersystem crossing quantum yields range from 0.82 to 0.35 for the pH range 2.0-9.5. The triplet energy is estimated as 1.7 X 10(2) kJ mol-1. With the primary photoproduct quantum yields, the overall photophysics and primary photochemistry of the fulvic acid may be described. The donor-acceptor model of humic spectra is also reinforced. Observed initial yields greatly exceed reported steady-state yields which appear to emphasize quenching and scavaging by humics themselves.

引用

页码：889 / 894

页数：6

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