Ethylenediamine tetraacetic acid is the edta full form. Ethylenediamine tetraacetic acid (EDTA) is a chemical used as an antioxidant and chelator. It helps remove heavy metals from the body, such its function in urine samples to test for diabetes or other diseases like cancer; EDTA reduces their effects on you by binding with them so they don’t have access damage healthy cells around your organs. It is also used as a preservative for blood samples.
As stated by the Interagency Coordinating Committee on the Validation of Alternative Methods, “the majority of validated methods for pharmaceuticals do not involve EDTA.” This committee consists of seven US agencies including the EPA, FDA and NTP (National Toxicology Program). They validate or review alternative testing methods that are both cost-effective and better for humans, animals and the environment.
Recently, the EPA has stated they do not recommend using EDTA. This is based on their study conducted in 1998 that was conducted to “evaluate the use of ethylenediaminetetraacetic acid (EDTA) as a chelating agent used in whole-body autopsies.” They found it made no difference in estimating exposure if samples were chelated with EDTA or not; this means it worsened accuracy of results when analyzing blood or urine samples for pesticide levels.
Based on their findings, the EPA concluded “that, while EDTA does precipitate metal ions under certain conditions (and therefore can be used as a chelating agent), there is no evidence that this is the case in whole-body autopsies nor that use of EDTA provides improved exposure estimates over not using EDTA.
EDTA is commonly used in laboratories worldwide, however, there are other substances that act as a chelating agent and are preferable. The EPA has approved six of these methods, including:
Ammonium or sodium sulfate
Ammonium or sodium sulfate, followed by high performance liquid chromatography (HPLC)
Dithizone, dithizone acetate, or dithizone carboxylate/bicarbonate
DTPA-7Na (sodium salt of EDTA) plus HPLC
DTPA-7Ca (calcium salt of EDTA) plus HPLC
-“Salting out” with ammonium sulfate, followed by HPLC.
The EPA concluded that while there are some chelating agents on this list that may worsen the accuracy of results (DTPA-7Na and DTPA-7Ca), the other 4 are preferable choices.
The FDA allows either chelating agents to be used if they are submitted for review, which is required by law when using a new test method that yields different results than previous methods. However, the EPA only recommends one over the other, while the other five can yield inaccurate results or not at all. The FDA does not have any conclusive evidence showing these alternatives are better or worse than EDTA.