共萃取是萃取化学中经常发生的现象。所谓共萃取是指某一元素(通常为微量元素)单独存在时不被萃取或萃取率很低,但有另一元素(通常为常量元素)存在时,难萃元素的萃取率大增,这一现象称之为共萃取。有时,在萃取某一元素时,另外一些元素也或多或少地混同萃取,称之为带同萃取。前者是有规律的现象,后者目前还无规可循。但是这两类现象很难截然分清,因此统称为共萃取进行讨论。共萃取机理比较复杂,但是,许多情况下,是由于生成异金属多核络合物、复杂离子缔合物和混配络合物等多元络合物,增加了可萃性。共萃取在痕量元素的分析化学中有实际意义。近年来研究工作逐渐增加。现就共萃 Co-extraction is a common phenomenon in extraction chemistry. The so-called co-extraction refers to an element (usually trace elements) is not present when the extraction alone or extraction rate is very low, but there is another element (usually a constant element), the extraction rate of hard-to-extract elements greatly increased, which A phenomenon called co-extraction. Sometimes, in the extraction of an element, some other elements are more or less mixed with the extraction, called with the extraction. The former is a regular phenomenon, which is still irregular. However, these two types of phenomena are difficult to distinguish clearly, so collectively referred to as co-extraction for discussion. The mechanism of coextraction is complicated, however, in many cases it is due to the formation of multiple complexes of heterometallic polynuclear complexes, complex ion complexes and mixed complexes, increasing the extractability. Co-extraction is of practical significance in the analytical chemistry of trace elements. In recent years, research gradually increased. Now on the co-extraction