Environmental Monitoring of Surface and Groundwater using Rhodamine Dye

As we prepare to showcase our metering pumps at Analytica, we wanted to share a common problem our pumps have solved.

Analytical sciences is an exact “quantitative” science which most often relies on precision fluid control of both samples and reagents to obtain the most accurate analysis.  One application where Fluid Metering’s valveless metering pumps have been very successful is in groundwater studies using rhodamine dye as a tracer chemical.  Though dosing and sampling procedures and data analysis methods vary with application, in general, the standard procedure in dye fluorometry hydrologic studies is to introduce a quantity of dye into a water body, and subsequently collect water samples over some spatial and temporal regime. These samples are then analyzed with a fluorometer for the concentration of the dye that is proportional to its fluorescence.

Dyes mimic the movement of water molecules. A measure of the movement of a dye (i.e., Rhodamine WT) will in effect be a measure of the movement of the water and, therefore, substances transported by the water in which it is introduced. Dispersion and mixing occur in all dimensions of the water body (Wilson, et. al. 1986). For example, in streams vertical mixing typically occurs first. Subsequently, and depending on current, channel configuration and stream characteristics, lateral mixing and longitudinal mixing follow. These phenomena are the subjects of interest to investigators employing dye fluorometry. For other bodies the sequence of mixing phenomena may vary, but the principle holds true nevertheless.

Fluid Metering’s QBG Low Current Metering Pumps are ideal for precision injection of rhodamine dye for surface, stream, and groundwater flow studies.  The three main reasons Fluid Metering’s QBG pumps are ideal for this application are as follows:

  1. Accuracy – As with any quantitative study, the results are only as accurate as the procedure and apparatus used.  FMI’s valveless design features only one moving part in fluid path, a sapphire-hard ceramic piston. This, as well as elimination of check valves from the pump design result in a metering pump having long term precision of 0.5%.
  2. Inert Internal Components – Using chemically inert ceramics and fluorocarbon wetted parts ensures that the pump will not skew results due to contamination contributed by the pump.
  3. Low Current Operation – The QBG consumes only 60 mA of power at 12VDC. Since, environmental studies are typically in remote locations, devices that run at low current will operate for extended periods of time on battery power.

At Fluid Metering we’re all about solving problems. With over 55 years of experience in providing dispensing and metering solutions we have worked with a variety of applications across several industries. Our metering pumps are also ideal for applications such as detecting chemical and physical properties of a substance such as blood chemistry instrumentation in the medical field as well as non-medical instrumentation for liquid and gas chromatography systems, pH monitors, and more.

To see how we can help you with your application be sure to visit us this week at Analytica in Munich, Germany. The trade show runs from April 1-4, 2014 and we’ll be located at Hall B2 Booth 338 showcasing our solutions for the pharmaceutical, chemical, food, plastics, and OEM industries.