**5. Conclusions**

In the case of the ion Pb2+, it can be seen that the solution of the complex EDTA with the ion P2+ gives a line which is very close to the reference line of the ionic solution Pb2+. This indicates that the amount of Pb2+ ion chelated is small in comparison to the solution of the chelate formed from the textured soya extract and the Pb2+ ion which has a line that is way below the reference line and the EDTA.

A similar conclusion for the study with the Fe3+ ion can be given.

With respect to the Cd2+ ion, the EDTA only acts as a chelate in concentrations lower than 0.04 grams of CdSO4 per 10ml of deionized water. On the other hand, the textured soya extract is a good chelate in a wider concentration range (between 0.01 and 0.1 grams of CdSO4 per 10ml of deionized water).

The chelate solution of EDTA for the Hg22+ ion does not have any effect on the Hg22+ ion in the test range from 0.01 up to 0.1 grams of HgCl2 per 10ml of water. However, the textured soya extracts act as a chelate only in concentrations lower than 0.15 grams of HgCl2 per 10ml of deionized water. The problem presented by this salt rests on the fact that it is a weak electrolyte and when it is placed in the water, it decomposes into two ions. Since the conductivity of the solution is measured in this study, the formation of two ions has a negative effect on the measurements obtained.

Just as in the case of Pb2+, Fe3+ and Ni2+ ions, the textured soya extract is a much better chelate than EDTA.

There is normally a low concentration (parts per million) of heavy ions in food. Thus our proposal of using the textured soya extract as the chelate for heavy ions instead of EDTA. In addition, as a result of the low concentration of ions, a solution with a low concentration of the textured soya extract will be used in order not to change the color, scent or taste of the food.

A problem to be considered in this application is that food is prepared with water which has salts that are ionized, and the textured soya extract will chelate some of these ions also. It will be necessary to perform tests on the food sample to determine if the application will be practical or not.

Another application possible is the extraction of heavy metals in water, cosmetics, and soils employing textured soya extract as the chelate for heavy ions instead of EDTA.
