2007 Annual Report
What’s New at the UNL Water Sciences Laboratory
By Daniel D. Snow, Ph.D.
Director of Laboratory Services,
UNL Water Sciences Laboratory
The number of analytical services provided by the University of Nebraska-Lincoln Water Sciences Laboratory (WSL) continues to grow.
Since last year, we’ve developed several new methods for supporting environmental research including two for emerging contaminants. We are also updating several working areas in our facility.
Our liquid chromatography-tandem mass spectrometry (LC-MS) method for algal toxins includes five different microcystins, as well as other freshwater toxins such as anatoxin-a and cylindrospermopsin. Direct injection of processed water samples allows detection of these compounds to about 1 part per billion. We are currently working on an on-line extraction method that will permit detection limits around 5 parts per trillion (0.005 ppb).
One reason for needing to measure these naturally produced substances at such low levels is the increased confidence in contaminant detection. There is a 50:50 chance of a “false positive” or incorrect identification at a compound’s detection limit for any given method.
Another reason is for studies examining the impact of these substances on drinking water supplies. For example, the U.S. Environmental Protection Agency recently issued a Request for Applications for research proposals to measure cyanotoxins in drinking water. A method that can go this low is needed in order to measure these and other similar contaminants in treated drinking water or in groundwater sources impacted by surface water where these contaminants are more likely to occur.
Another group of contaminants that we are using on-line extraction LC-MS is steroid hormones. Detection limits at the parts per trillion level are critical for accurate measurement of reproductive hormones such as estradiol and anabolic steroids trenbolone.
We are beginning work on a three-year study funded by EPA to understand the environmental fate and transport of these and other steroid hormones from livestock feeding operations. This project will require analysis of hundreds of samples for low levels of steroid hormones.
Recent studies by the U.S. Geological Survey and others have shown that parts per trillion levels of some steroid hormones are detectable in U.S. waterways. Scientists have shown that steroids such as these can have an impact on aquatic life at these levels.
Using on-line extraction method we can detect a suite of twelve steroids at concentrations as low as 0.5 parts per trillion in water using LC-MS with electrospray ionization.
When we use this method on highly contaminated samples such as wastewater however, we find that the other contaminants in the sample severely affects the sensitively of the method. Fortunately, we obtained funding to purchase a new ionization “source” for our LC-MS called atmospheric pressure photoionization. This new “Ion Sabre” source from Syagen Technology has been shown to improve ionization of hard to ionize compounds like steroids and at the same time overcome the matrix suppression issue so common in methods using electrospray ionization.
WSL chemist Dave Cassada and LC-MS technologist Teyona Damon have been instrumental in developing our methods and the UNL Water Center has helped in providing funds for the new “Ion Sabre” source to help get us going on this EPA study.
Finally, the offices and conference room in the WSL are undergoing renovation this spring. It’s been almost 17 years since the building was renovated and we were sorely in need of new carpeting and a fresh coat of paint. Add some modular furniture left over from the School of Natural Resources recent move into Hardin Hall and we have a great “new” working environment for the WSL staff.
We plan an open house later this year to let people see some of the new equipment we have and the renovated spaces we are working in.
