Wet Chemistry Facilities

NREL maintains an Alpkem Flow Solution IV Automated wet chemistry system (O.I. Analytical, College Station TX). The instrument features a 270 position random access auto sampler and the ability to use either segmented flow analysis (SFA) or flow injection analysis (FIA). Two auto ranging detector channels allow simultaneous measurement of two ionic species at up to 60 samples per hour.Currently available chemistries include:

• Ammonium (NH₄⁺) by segmented flow analysis.
• Nitrate + Nitrite (NO₃^-+NO₂ ^-) by flow injection analysis.
• Nitrite (NO₂^-) by flow injection analysis.
• Orthophosphate (PO₄^3- ) by segmented flow analysis.

The instrument is principally used for analyzing water samples and soil extracts. Current usage is approximately 5000 analyses per year.

The instrument can be configured to measure:

• total carbon
• total organic carbon
• total inorganic carbon
• total nitrogen
• total carbon/total nitrogen
• total organic carbon/total nitrogen
• Dissolved organic carbon and dissolved nitrogen may be measured by filtering the samples first.
• Organic nitrogen can be determined by measuring the total nitrogen on this instrument and the inorganic nitrogen on the Alpkem.

The instrument is principally used to analyze lake water, stream water, and soil microbial biomass extracts. Current usage is approximately 2000 sample per year.

The instruments are available for use mainly by NREL Principal Investigators but arrangements can be made for use by CSU and other collaborators.