中文摘要：

利用微量热计MicroDSCⅢ对重金属离子影响脲酶催化水解反应的过程进行研究，并探讨重金属离子联合抑制作用对脲酶催化反应的影响．结果表明，在25℃下，重金属离子对脲酶水解反应热有影响，在广泛浓度范围（0．1，1，10，100和10^3mg／L）内，这种影响不仅表现在抑制作用方面，而且会促进其水解反应的进行，如铜离子在100和1000mg／L时抑制率分别为（0．49±0．20）％和（-11．93±1．34）％．重金属离子浓度与抑制率具有显著或极显著的相关性，抑制效果的顺序为砷离子〉铅离子〉镉离子〉铜离子．当重金属离子联合抑制时，其抑制效果与抑制率较高的重金属离子的抑制作用接近．

英文摘要：

Inhibiting effects of heavy metal ions on urease-catalyzed reaction were investigated with microcalorimetry. Further, the joint inhibition effects of two heavy metal ions on urease-catalyzed reaction were also conducted. The results indicate that, with a wide range of concentration（0. 1, 1, 10, 100 and 103 mg/L）, heavy metal ions not only inhibit urease hydrolysis reaction, but also can promote this reaction in some concentration range. For instance, inhibition rate is （0. 49±0.20） % and （-11.93±1.34） % when Cu2＋concentration is 100 and 1000 mg/L, respectively. The correlation between urease inhibition rate and concentration of heavy metal ion is very significant, and the inhibition effects are： As3＋ 〉Pb2＋ 〉Cd2＋ 〉Cu2＋. The joint inhibition is close to that with higher inhibition when two heavy metal ions are used together. This work proves that the micro-calorimetry may be a potential method to rapidly and accurately detect heavy metals.