One way to think about the problem is that you could provide enough 1-liter batches of water to have the laboratory analyze all the constituents that we can determine currently. This would result in a lot of nondetects, a big bill, and an unhappy cooperator. A second way would be to try to selectively preconcentrate trace inororganic constituents by processing large volumes of water. This is a labor-intensive approach that would result in data with a lot of qualifiers, but the probability is higher that you would detect more analytes. However, once again you would spend a lot of money and would have data for only one parcel of water at one point in time.
Alkalinity is a function primarily of carbon dioxide concentration in the water sample.
Both alkalinity and dissolved oxygen are directly influenced by small changes in atmospheric partial pressures of carbon dioxide and oxygen, respectively. Also, whether filtered or not, water samples contain bacteria, whose metabolic activities can profoundly influence alkalinity and dissolved oxygen. Unfortunately, there is no practical way to seal samples in the field so that subsequent shipping and storage won't affect these results. I think that the results from Hach and immunoassay tests have to be clearly defined and delimited. Immunoassay kits are being used primarily for trace organic compounds.