EDTA一般指乙二胺四乙酸或其鈉鹽，是一種重要的人造有機多元酸螯合劑，能與大多數(shù)金屬離子形成穩(wěn)定絡(luò)合物。EDTA可生成四種鈉鹽，隨著鈉原子取代數(shù)增加，在水中溶解度也逐漸提高。

EDTA generally refers to ethylenediamine tetraacetic acid or its sodium salt, which is an important artificial organic polybasic acid chelator and can form stable complexes with most metal ions. EDTA can generate four kinds of sodium salts. With the increase of the number of sodium atoms, the solubility in water will gradually increase.

EDTA初應(yīng)用于化妝品是將其加入到肥皂或洗面奶中，目的是軟化硬水（機理是EDTA能螯合金屬離子），使皂基泡沫更豐富持久；然后到了20世紀(jì)50年代后期，又有研究發(fā)現(xiàn)EDTA能提高化學(xué)防腐劑的性能，因而在化妝品行業(yè)中更受重視。

When EDTA is first applied to cosmetics, it is added to soap or facial cleanser to soften hard water (the mechanism is that EDTA can chelate metal ions) and make soap based foam richer and more durable; Then, in the late 1950s, it was found that EDTA could improve the antibacterial properties of chemical preservatives, which attracted more attention in the cosmetics industry.

一、螯合作用。

1、 Chelation.

當(dāng)溶液中存在金屬離子時，EDTA就像螃蟹的大鉗子一樣鉗住金屬離子不放，使得金屬離子很難發(fā)生正常價態(tài)反應(yīng)，俗稱螯合作用。為什么要螯合這些金屬離子呢？以鈣、鎂、鐵、銅、錳等離子為例，它們在稀溶液中是以二價陽離子形式存在，與陰離子會反應(yīng)生成鹽并沉淀析出，如日常生活中常常遇到的茶壺內(nèi)壁結(jié)茶垢現(xiàn)象。

When there are metal ions in the solution, EDTA will hold the metal ions like a crab's tongs, making it difficult for the metal ions to react with normal valence, commonly known as chelation. Why should we chelate these metal ions? Take calcium, magnesium, iron, copper and manganese plasma as an example. They exist in the form of divalent cations in dilute solution. They react with anions to form salts and precipitate, such as the phenomenon of tea scaling on the inner wall of teapots often encountered in daily life.

此類金屬離子污染物同樣會出現(xiàn)在化妝品中，生產(chǎn)用水、原料、制造設(shè)備、容器和包裝等都可能引入金屬離子，然后導(dǎo)致化妝品變色、變味、變渾濁、加速腐敗等現(xiàn)象。在化妝品配方中加入0.05％-0.2％EDTA，然后這些EDTA溶于水就會與金屬離子牢牢結(jié)合，使其不能再與陰離子反應(yīng)，從而防止或降低上述不良現(xiàn)象的發(fā)生。

Such metal ion pollutants will also appear in cosmetics. Production water, raw materials, manufacturing equipment, containers and packaging may introduce metal ions, which will lead to cosmetics discoloration, taste change, turbidity, accelerated corruption and other phenomena. Add 0.05% - 0.2% EDTA into the cosmetics formula, and then these EDTA will be firmly combined with metal ions when dissolved in water, so that they can no longer react with anions, thus preventing or reducing the occurrence of the above adverse phenomena.

二、協(xié)同防腐。

2、 Synergistic corrosion protection.

EDTA的能力主要是針對于革蘭氏陰性菌，如大腸桿菌、痢疾桿菌、肺炎桿菌、霍亂弧菌等，尤其針對綠膿假單胞菌，即使單獨使用也能產(chǎn)生明顯的作用。實驗表明，不加其他化學(xué)防腐劑，單獨使用250ppm濃度的EDTA，可殺死99.99%的綠膿假單胞菌，當(dāng)濃度降100ppm時，綠膿假單胞菌的死亡率在57%-99.5%。

The antibacterial ability of EDTA is mainly aimed at gram-negative bacteria, such as Escherichia coli, dysentery bacilli, pneumonia bacilli, Vibrio cholerae, etc., especially for Pseudomonas aeruginosa. Even if used alone, it can produce obvious bactericidal effect. The experiment showed that the use of EDTA with a concentration of 250 ppm alone without other chemical preservatives could kill 99.99% of Pseudomonas aeruginosa. When the concentration dropped to 100 ppm, the mortality rate of Pseudomonas aeruginosa was 57% - 99.5%.

此外，EDTA對某些酵母菌和霉菌也有很好的效果，但是一般來說不建議單獨使用，好與其他防腐劑協(xié)同使用才能發(fā)揮更好的作用。機理：EDTA能與微生物細胞壁中的金屬離子相結(jié)合，使微生物細胞壁滲透性提高，有利于劑的滲透和發(fā)揮作用。您有什么問題或者需求就來我們網(wǎng)站咨詢看看http://www.rebackmall.com吧！

In addition, EDTA also has good effects on some yeasts and molds, but it is generally not recommended to use it alone. It can play a better antibacterial role only when it is used together with other preservatives. Antibacterial mechanism: EDTA can combine with metal ions in microbial cell wall to improve the permeability of microbial cell wall, which is conducive to the penetration and function of antibacterial agents. If you have any questions or needs, please come to our website for consultation http://www.rebackmall.com Come on!