PHOTOCHEMISTRY OF HALOGENATED BENZENE-DERIVATIVES .10. EFFECTS OF SODIUM-CHLORIDE ON THE AQUATIC PHOTODEGRADATION OF BROMOXYNIL (3,5-DIBROMO-4-HYDROXYBENZONITRILE) HERBICIDE

被引:13
作者
KOCHANY, J [1 ]
CHOUDHRY, GG [1 ]
WEBSTER, GRB [1 ]
机构
[1] UNIV MANITOBA, DEPT SOIL SCI, PESTICIDE RES LAB, WINNIPEG R3T 2N2, MANITOBA, CANADA
关键词
D O I
10.1007/BF01054973
中图分类号
X [环境科学、安全科学];
学科分类号
08 ; 0830 ;
摘要
Aqueous solution phase photochemistry of the herbicide bromoxynil (3,5-dibromo-4-hydroxybenzonitrile) (1) in the presence of various concentrations of sodium chloride was extensively investigated with ultraviolet radiation near 313 nm. In the presence of 0.5 to 25.0x10-3 M NaCl, the quantam yields for the phototransformation of the herbicide bromoxynil (1) amounted to 0.045±0.005 to 0.017±0.007 vs. 0.052±0.004 in the absence of sodium chloride. These quantum yield data for the photolysis of 1 followed the Stern-Volmer equation. The photolysis of the 7.8x10-6 M aqueous solution of the herbicide 1 in the presence of sodium chloride (10.0x10-3 M) gave rise to the formation of 3-bromo-4-hydroxybenzonitrile (2), 3-bromo-5-chloro-4-hydroxybenzonitrile (3), 3-chloro-4-hydroxybenzonitrile (4), and 4-hydroxybenzonitrile (4A). The products 3 and 4 were formed via the photoincorporation of chloride ions into bromoxynil (1) and into the primary photoproduct 2, respectively. In the case of this photoreaction of the chemical 1, the percentages of maximum concentrations of the photoproducts 3, 2, 4, and 4A were obtained after 10.5, 20.0, 30.0, and 44.0-min exposures to UV light, respectively, the percentage disappearance of the starting material 1 being 90% for 44-min photolysis. Photoproducts 2, 3, 4, and 4A were identified with the aid of GC-MS. The formation of 4-hydroxybenzonitrile (4A) decreased with the rise in concentration of NaCl. When a mixture of aqueous solutions of 3.0 mL bromoxynil (2.0x10-4M) plus 0.5 mL NaCl (0.5 M) was exposed to UV light for up to 3 hr, the photoproduct 4A could not be observed; however, other products, namely, phenols 2-4 were produced. © 1990 Springer-Verlag New York Inc.
引用
收藏
页码:325 / 331
页数:7
相关论文
共 22 条
[1]  
BARLTROP JA, 1975, EXCITED STATES ORGAN, P1
[2]   HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC DETERMINATION OF BROMOXYNIL OCTANOATE AND METRIBUZIN IN RUNOFF WATER FROM WHEAT FIELDS [J].
BROWN, DF ;
MCDONOUGH, LM ;
MCCOOL, DK ;
PAPENDICK, RI .
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY, 1984, 32 (02) :195-200
[3]  
CALVERT JG, 1966, PHOTOCHEMISTRY, P1
[4]  
Choudhry G. G., 1984, The handbook of environmental chemistry. Volume 1. Part C. the natural environment and the biogeochemical cycles, P1
[5]   PHOTOCHEMISTRY OF HALOGENATED BENZENE-DERIVATIVES .5. PHOTOLYTIC REDUCTIVE DECHLORINATION AND ISOMERIZATION OF TETRACHLOROBENZENES IN ACETONITRILE-WATER MIXTURES [J].
CHOUDHRY, GG ;
WEBSTER, GRB .
TOXICOLOGICAL AND ENVIRONMENTAL CHEMISTRY, 1985, 9 (04) :291-308
[6]   PHOTOCHEMISTRY OF HALOGENATED BENZENE-DERIVATIVES .8. PHOTOFORMATION OF 2-METHYL-4,5,6,7-TETRACHLOROBENZOXAZOLE FROM PENTACHLOROPHENOL IN WATER ACETONITRILE [J].
CHOUDHRY, GG ;
GRAHAM, NJ ;
WEBSTER, GRB .
CANADIAN JOURNAL OF CHEMISTRY-REVUE CANADIENNE DE CHIMIE, 1987, 65 (09) :2223-2233
[8]  
CHOUDHRY GG, 1982, J CHEM SOC PERK T 1, P2957, DOI 10.1039/p19820002957
[9]  
CHOUDHRY GG, 1985, RESIDUE REV, V96, P79
[10]   ENVIRONMENTALLY SIGNIFICANT PHOTOCHEMISTRY OF CHLORINATED BENZENES AND THEIR DERIVATIVES IN AQUATIC SYSTEMS [J].
CHOUDHRY, GG ;
WEBSTER, GRB ;
HUTZINGER, O .
TOXICOLOGICAL AND ENVIRONMENTAL CHEMISTRY, 1986, 13 (1-2) :27-83