Follow NEMC
 |
 |
 |
Automated In-line Digestion and Analysis of Total Phosphorous (TP) and Total Nitrogen (TN) in Environmental Water Samples
Oral Presentation
Prepared by W. Lipps
OI Analytical, 151 Graham Road, College Station, Texas, 77845
Contact Information: william.lipps@xyleminc.com; 979-690-5230
ABSTRACT
A high proportion of the workload in environmental laboratories involves analysis of total phosphorous (TP) and total nitrogen (TN) in water samples for Clean Water Act compliance reporting. At the present time these analyses must be performed using manual or semi-automated methods as there are no U.S. EPA-approved automated methods.
The U.S. EPA parameter for total nitrogen is the sum of Total Kjeldahl Nitrogen (TKN) and Nitrate plus Nitrite Nitrogen. Water samples that have undergone Kjeldahl digestion can be analyzed for total phosphorous as well as TKN which only partially mitigates sample handling and workload issues. Fully automated simultaneous analysis of TP and TN cannot be achieved because an approved method for determining TN as a single analyte is not available.
This presentation will examine the use of an alkaline persulfate digestion as an alternative to Kjeldahl digestion to support analysis of both total nitrogen and total phosphorous. Analytical results obtained from automated in-line digestion and simultaneous analysis of TP and TN will be presented and contrasted with results obtained by currently approved manual and semi-automated methods. Differences in analyst time, reagent consumption, sample throughput, and hazardous waste generated by each technique will also be summarized and reported.
Oral Presentation
Prepared by W. Lipps
OI Analytical, 151 Graham Road, College Station, Texas, 77845
Contact Information: william.lipps@xyleminc.com; 979-690-5230
ABSTRACT
A high proportion of the workload in environmental laboratories involves analysis of total phosphorous (TP) and total nitrogen (TN) in water samples for Clean Water Act compliance reporting. At the present time these analyses must be performed using manual or semi-automated methods as there are no U.S. EPA-approved automated methods.
The U.S. EPA parameter for total nitrogen is the sum of Total Kjeldahl Nitrogen (TKN) and Nitrate plus Nitrite Nitrogen. Water samples that have undergone Kjeldahl digestion can be analyzed for total phosphorous as well as TKN which only partially mitigates sample handling and workload issues. Fully automated simultaneous analysis of TP and TN cannot be achieved because an approved method for determining TN as a single analyte is not available.
This presentation will examine the use of an alkaline persulfate digestion as an alternative to Kjeldahl digestion to support analysis of both total nitrogen and total phosphorous. Analytical results obtained from automated in-line digestion and simultaneous analysis of TP and TN will be presented and contrasted with results obtained by currently approved manual and semi-automated methods. Differences in analyst time, reagent consumption, sample throughput, and hazardous waste generated by each technique will also be summarized and reported.