Seruga M, Hasenay D
Faculty of Food Technology, University of Osijek, Croatia.
Z Lebensm Unters Forsch. 1996 Apr;202(4):308-12. doi: 10.1007/BF01206102.
The corrosion of aluminium (Al) in several brands of soft drinks (cola- and citrate-based drinks) has been studied, using an electrochemical method, namely potentiodynamic polarization. The results show that the corrosion of Al in soft drinks is a very slow, time-dependent and complex process, strongly influenced by the passivation, complexation and adsorption processes. The corrosion of Al in these drinks occurs principally due to the presence of acids: citric acid in citrate-based drinks and orthophosphoric acid in cola-based drinks. The corrosion rate of Al rose with an increase in the acidity of soft drinks, i.e. with increase of the content of total acids. The corrosion rates are much higher in the cola-based drinks than those in citrate-based drinks, due to the facts that: (1) orthophosphoric acid is more corrosive to Al than is citric acid, (2) a quite different passive oxide layer (with different properties) is formed on Al, depending on whether the drink is cola or citrate based. The method of potentiodynamic polarization was shown as being very suitable for the study of corrosion of Al in soft drinks, especially if it is combined with some non-electrochemical method, e.g. graphite furnace atomic absorption spectrometry (GFAAS).
采用电化学方法，即动电位极化法，研究了几种品牌软饮料（可乐型和柠檬酸盐型饮料）中铝（Al）的腐蚀情况。结果表明，软饮料中铝的腐蚀是一个非常缓慢、随时间变化且复杂的过程，受到钝化、络合和吸附过程的强烈影响。这些饮料中铝的腐蚀主要是由于酸的存在：柠檬酸盐型饮料中的柠檬酸和可乐型饮料中的正磷酸。铝的腐蚀速率随着软饮料酸度的增加而上升，即随着总酸含量的增加而上升。由于以下事实，可乐型饮料中的腐蚀速率比柠檬酸盐型饮料中的腐蚀速率高得多：（1）正磷酸对铝的腐蚀性比柠檬酸强；（2）根据饮料是可乐型还是柠檬酸盐型，铝表面会形成性质截然不同的钝化氧化层。动电位极化法被证明非常适合研究软饮料中铝的腐蚀，特别是如果将其与一些非电化学方法，如石墨炉原子吸收光谱法（GFAAS）相结合。
