If you want to test 2 or more toxins on a sample, the best method to use is an optimal response surface. ORS is a type of designed experiment. So, you'll need software that is capable of designing one. I use Design Expert from Stat Ease. JMP from SAS and R are also capable software.
The ORS will test different combinations of each toxin you test. You can add in ideas about gender of species, type of species, seasonal effects, etc.