How did you determine the TDS? Did you do a conductivity measurement or a gravimetric determination? What do you know about the individual chemical species present in your sample?

With the exception of simple electrolyte solutions, there is no direct relationship between TDS and type of ions dissolved. From a single TDS measurement it is not possible to tell apart which ions are present in a water sample. Chemical speciation is not possible, because the TDS measurement takes into account the global contribution of all the species present in the sample. It is not a selective method.

However, if you know something about the chemistry of your water sample, you can make some physically sound assumptions.