除草剂苄嘧磺隆在针铁矿表面吸附的红外光谱研究

文章用FTIR光谱,探讨了热带、亚热带地区水稻土中普遍存在的针铁矿对近年来广泛使用于水稻田的磺酰脲类除草剂苄嘧磺隆的吸附机理。结果表明:(1)在针铁矿对苄嘧磺隆的吸附过程中,游离羟基(A型)及C型羟基均没有明显作用。(2)针铁矿表面的水合羟基峰在吸附前后的图谱中由3158移到3129cm~(-1),缔合程度增高,表明在该吸附过程中针铁矿表面的水合羟基峰起主要作用。(3)在吸附后的针铁矿图谱中出现了波数增高了的苄嘧磺隆的羰基及磺酰基弱峰。其波数分别由1712和1161cm~(-1)增至1789和1164cm~(-1),由此判断,苄嘧磺隆被针铁矿表面吸附是由该农药分子中的羰基和磺酰基起主要作用。(4)由以上结果推断:苄嘧磺隆在针铁矿表面的吸附是苄嘧磺隆分子中的羰基和磺酰基与针铁矿表面的水合羟基形成了电荷-偶极键以氢键结合的吸附。

FTIR Study on the Adsorption of Bensulfuron-methyl by Goethite

A FTIR study on bensulfuron-methyl adsorption by goethite has been carried out. The results showed that the free hydroxyl groups on the surface of goethite did not have any action on bensulfuron-methyl. After adsorption, the peak of the hydrate hydroxyl groups shifted from 3 158 to 3 129 cm-1. There were two peak (1 789 and 1 164 cm-1) added in the spectrogram of goethit after bensulfuron-methyl were adsorbed by goethite, which were from carbonyl group(1712 cm-1) and sulfonyl group (1 161 cm-1) of ben-sulfuron-methyl respectively. This fect indicated that the adsorption of bensulfuron-methyl on goethite occurred through carbonyl group and sulfonyl group of bensulfuron-methyl with hydrate groups on the surface of goethite. One mechanism of bensulfuron-methyl adsorption on goethite was proposeed: the adsorption was hydroxyl conducted by means of charge-dipole interaction (mainly hydrogen bonding).