Methods of forming chelating compositions

The present invention relates to a method comprising: combining sodium glutamate and/or glutamic acid with formaldehyde to form a first combination; adding hydrogen cyanide to form a second combination, wherein the second combination comprises glutamic acid diacetonitrile monosodium salt, cyclic GLMN and glutamic acid N-single acetonitrile sodium salt; maintaining the second combination at a temperature of less than about 16 DEG C and a pH of less than about 7; converting the nitrile groups to carboxylate groups to form a third combination comprising water and at least about 47% by weight of tetrasodium GLDA wherein the reaction yield is at least about 91%; providing a fourth combination comprising water and a tetrasodium salt of GLDA and having a pH of less than about 7; and combining the third and fourth combinations to form the chelating composition. 本发明涉及一种方法，所述方法包括：将谷氨酸钠和/或谷氨酸与甲醛组合以形成第一组合；添加氰化氢以形成第二组合，第二组合包含谷氨酸二乙腈单钠盐、环状GLMN和谷氨酸N-单乙腈钠盐；将第二组合维持在温度低于约16℃且pH低于约7；将腈基团转化为羧酸盐基团，从而形成包含水和至少约47重量％的GLDA四钠盐的第三组合，其中反