Don’t Miss SGS’s presentations by Dr. Doss and Arash Sharifi at the 2025 Environmental Measurement Symposium! 

Dr. Doss will serve as co-chair for the Environmental Forensics session on Tuesday, August 5th, between 1:00-3:00 PM, and will also present “Forensics Analysis – Gasoline Releases”, at 2:00 pm within the same session. 

Gasoline spills and leakages from Underground Storage Tank (UST) leaks are common occurrences in the United States. They are typically referred to as Light Non Aqueous Liquids (LNAPLs). There are historical releases, leaks from several sources in the same vicinity, and recent releases. This presentation will provide the tools necessary to measure the contaminants released into the ground which in many cases end up in the groundwater aquifers. 

This presentation will outline the analysis required to determine the composition of the product released and approximate age of the product by analyzing the product for indicator parameters such as additives. Typically, Whole Oil Analysis is performed to identify the products. Once the product is identified more sophisticated analysis such as PIANO analysis and additives identification is performed in the laboratory. Diagnostic ratios will be discussed as to the various pathways the weathering of the product proceeds in the environment. All necessary tools required for data assessment will be outlined. 

Additionally, Dr. Doss will present “PFAS in Air – Method OTM-50”, on Thursday, August 7th at 4:00 pm. 

PFAS in air is a burning topic in the “Forever Chemicals World”. Although OTM-45 method has been in use for a while that method is an impinger sample collection method in a liquid and analyzed by EPA method 1633 or 537 (mod.). OTM -50 is an Air method, wherein, samples are collected in SUMMA canisters akin to TO-15A. OTM-50 names a target compound list of 30 PFAS compounds. The differences between regular PFAS LC/MS/MS OTM-45 and OTM-50 methods will be discussed. US EPA requires that 30 PFAS compounds be analyzed as provided in the OTM-50 method. 

The analytical standards, surrogates and internal standards will be outlined for the OTM -50 method. Unlike regular PFAS standards the sources from which standards are acquired are quite different. 

Method OTM-50 and its process on sample collection and analysis will be outlined. Data from OTM-50 method will be discussed. 

Besides, Arash Sharifi, will be presenting “Boron Isotope as a Powerful Tool for Nutrient Source Tracking: A Multi-isotope Study of Surface-water in South Florida” on Tuesday, August 5th at 1:00 pm. 

With 260,000 Km2 expansion of the aquifer, Florida has abundant surface and ground-water resources providing fresh water for 11 million Floridians—these can easily be contaminated. Exposure to contaminated drinking and recreational waters threatens public health. Excessive urban development and rapid population growth in South Florida are straining the freshwater resources of the region and climate impacts on the water availability imposed another layer of stress on these vulnerable resources. Nutrient input, heavy metals, and organic enrichment as well as bacterial contamination represent the leading causes of degraded water quality in lakes, rivers, estuaries, and coastal waters of South Florida. Nutrient pollution, mainly nitrate, in surface water has become an environmental problem of both regional and national concern. In order to provide a successful management program for effective control of the nitrate pollution in surface water, it is essential to both identify the pollution sources and reduce the input of nitrate. This became even more important in a large aquifer system such as the one in Florida where contaminants from different point sources and non-point sources find their ways into the hydrological system. During the past decades, nitrogen and oxygen isotopes of nitrate (δ15NNO3 and δ18ONO3) has conventionally been utilized for identifying the source and fate of nitrate pollution in surface-water.  

Please Contact us to request a copy of these presentations.

We can’t wait to see you there!

For more information, contact:

Kesavalu Bagawandoss, Ph.D., J.D.
Technical Director, North America
[email protected]
+1 281 881 1457

SGS North America, Inc.
500 Ambassador Caffery Parkway,
Scott, LA, 70583