Dynaflow has expertise in identification and quantifying polar pharmaceuticals and personal-care-products (PPCP) in water and wastewater, including raw sewage influent. We have analyzed over 500 water and wastewater samples for PPCP; including over 300 using the USGS 1433 method (other methods can be used or developed for special analysis). The Dynaflow laboratory is equipped with a Perkin Elmer Clarus 500 gas chromatograph with mass detector (GC/MS). The Clarus 500 is capable of collecting Total Ion Count (TIC) and Selected Ion Monitoring (SIR) simultaneously, which greatly enhances its utility for identifying unknown compounds and achieving low detection limits

Perkin Elmer Clarus 500: Gas Chromatograph/Mass Spectrometer.

Case Study: Seasonal Variations in Pesticide and Fragrance Concentrations in WWTP Effluent.


Effluent from a wastewater treatment plant (WWTP) in Minnesota was sampled 129 times between May 2009 and April 2011, and the concentrations of 48 compounds were determined using the USGS 1433 method for analysis of wastewater compounds. The advantage of such a rich data set is that seasonal trends can be more easily determined. These seasonal variations can be due to a number of factors including usage rate or loading of the PPCP, or changes in the removal efficiency of the upstream WWTP processes. The concentrations of two compounds, the mosquito repellent, DEET (N, N-diethyl toluamide), and the fragrance compound HHCB (galaxolide) illustrate this well. The DEET concentrations show a clear increase beginning in May and then decrease after September, but still remain above the detection limit even in the winter months. This correlates with the expected usage rate of the topical pesticide in the warmer months when the mosquito populations in Minnesota are famously high.

Seasonal variation in DEET concentration in WWTP effluent from Minnesota.

HHCB, or galaxolide, is a fragrance that is commonly used in soaps, shampoos, cosmetics, cleaning products, and detergents. Unlike DEET its consumption is not seasonal; due to its ubiquity in so many consumer products its concentration in the influent wastewater is nearly constant throughout the year. However, the concentrations of HHCB in the WWTP effluent are significantly higher in the winter months (January to March). This is most likely due to less efficient removal in the WWTP because of lower biological metabolic rates in the cold Minnesota winter.

 Concentrations of HHCB in WWTP effluent are greater in the winter months than at other times of the year.