[mmartin798]

Since you have both your Expanded Nuclear, Biological and Chemical Independent Field Kit and a Spectrometer, which have similar functionality only differing in sensitivity, speed or depth of database, you might as well add a GC-MS to the mix. We use them in the lab, after differing extraction methods, to test for volatile and semi-volatile compounds, PCBs, and PFAS. It's roughly the same size as an ICP-AES instrument (I think your spectrometer is OES, but they do similar things).

The GC-MS can detect down to ng/L or ng/Kg(1), depending on the matrix of what you are analyzing. Each sample will take somewhere between 20-40 minutes to process depending on the detection limit and level of interference compounds in the sample. If the interference it too great, you will have to rerun the sample after a cleanup procedure. Also if contamination is too high, you will saturate the sensor and have to rerun the sample after you dilute it and have run a cleaning/purge cycle on the instrument. This cycle takes about an hour to run. If the sample was particularly "nasty" (lots of interference compounds, extremely high levels, etc) there is a chance the column will be compromised and need to be replaced. It only takes about 15 minutes to swap out the column, but it takes about 8 hours to get the column to stabilize and be calibrated.

The spectrum is sent to a computer for analysis. The database is used to identify peak and give a breakdown of compounds. Integration of the peaks yields the amounts of the compounds. If two similar compounds are in high enough concentrations in the sample, it may not be possible to resolve the difference between them.

As I mentioned, it is about the same size as the spectrometer and the same sample prep/extraction station can be used for both.

1: Many modern GC-MS can do pg/L and pg/Kg, though reporting limits that small are rare. For instance, PFAS and PFOS, compounds for which it is now believed there may be no safe exposure to without some harm, now have an EPA maximum level of 4 ng/L in drinking water. Anything lower cannot be feasibly enforced with current technology for mass purification.