These devices already exist, and have existed for years, in various sizes, combinations of anylites, expense, and complexity.
HACH, and many companies offer them. Check a Fisher Scientific catalog.
I used to use one in a chem lab that had the capacity to analyze and measure hundreds of chemicals, although each needed its own reagents to be mixed to ID and quantify results. I used the one below hidden in the back for testing ammonia, the actual unit cost more than my truck.
Some were road worthy and would analyze a few components with only slight mixing, very quickly.
Like this decades old chlorine monitor.
The possibility of using new technology, and creating one inexpensive enough would surely be quickly used everyone.
