In Spec8 and React, you can automatically speciate many samples at once using Cl as a make-up ion if a charge imbalance exists. However, it is not clear how one can do the same thing using bicarbonate as a makeup ion instead. I have 100's of samples that I need to run, so doing this by hand is not efficient. In Spec8, I read in the GWB manual that you can add additional arguments in the command pane found in the menu when selecting samples to run (accessed from the GSS file), however, it's not clear what kind of arguments can be input there or perhaps more importantly, what the variable name would be to set bicarbonate as the make-up ion. There are "header commands" and
trailer commands" listed as additional input, just can't figure out what command initiates a bicarbonate charge balancing.
Along these lines, I was attempting to manually calculate charge imbalance so that I could use this information to manually calculate a new bicarbonate concentration, but I cannot seem to match the calculated charge imbalance values from GWB. I know that GWB uses the equation: 100*[(Sum cations-Sum anions)/(Sum cations+Sum anions)], but when I perform this calculation, I cannot recreate exactly the charge imbalance output. The concentration data of interest was converted to mEq/L and multiplied by the charges to sum the cations and anions. Part of this could be due to not fully understanding how GWB handles H+ in this calculation, but could you provide any further explanation as to how GWB exactly calculates charge imbalance? Are ALL major cations and anions in the GSS file always used to calculate charge imbalance, or are only the major cations and anions used in the calculation? Based on the forum information, it's not quite clear how exactly GWB deals with charge imbalance.
Any help would be greatly appreciated.
