White Papers Oil/Grease Analyzers
Solvent Choices for Infrared Testing of Oil and Grease in Water
Water is a very strong absorber in the mid infrared (IR) region where
oil is measured. We see the effect of infrared absorbance when a cold
bucket of water is left in the sun is quite warm by afternoon due to the
absorption of infrared energy as heat. When measuring part per million
(ppm) oil levels with mid IR, the water absorbs so much of the infrared
energy that the signal becomes saturated and low oil levels cannot be
detected. The oil in the sample needs to be separated from the water in
order to make a measurement. Typically, the oil is extracted into a
solvent and then measured either directly in the solvent or the residual
oil is measured after solvent evaporation.
Infrared Analysis Reduces EPA FOG Testing Costs and Provides Fast Results
Wastewater professionals who are enforcing industrial effluent standards for fats, oil and
grease (FOG) either must perform numerous gravimetric tests or spend a considerable amount
of money with a contracted testing laboratory. Infrared analysis provides an alternative which
will significantly reduce costs and save time...Read More
Emulsion Breaking Techniques for Oil in Water Solvent Extractions
Certain types of samples, such as those containing detergent, may
form emulsions when doing an oil in water extraction into a solvent.
The boundary between the solvent and the sample will have an emulsion
layer that has a cloudy or milky appearance as shown in this photo.
According to U.S. EPA Method 1664, “if the emulsion is greater than
one-third the volume of the solvent layer, the laboratory must employ
emulsion-breaking techniques to complete the phase separation”. This
is relevant to all oil in water measurements that use liquid-liquid
extraction whether the analysis is done by infrared, gravimetric or UV.
If such an emulsion cannot be broken by any attempted means, the test
method may not give representative results for the problem sample. The
best way to break or reduce the emulsion depends on the sample
Comparing Oil in Water Methods
While the amount of oil in water is highly regulated -- it
can also be a challenging measurement.
It is complicated by the fact that oil comes in many forms and the
measurement is defined by the particular regulatory method. When EPA 1664 is the regulatory method, the
“oil” is anything that is extracted into hexane and remains after the hexane
has been evaporated and shows up as weight.
In regions where infrared analysis is the defining method, the “oil” is
whatever is extracted into the solvent and has carbon-hydrogen bonds that
absorb infrared light at a specific frequency.
Each method is looking at different properties of oil and can
potentially give different results.
Anyone involved in field analysis of oil in water will
continually get the question “Does your equipment match the regulatory method?”
White Papers Biofuels Analyzers
On-Site Ethanol in Gasoline Blend Analysis is an Investment that Saves Money and Eliminates Uncertainty in Fuel Blends
The use of ethanol as a gasoline additive has increased dramatically
over the past few years and will likely continue to increase. For fuel
blenders, this means an added challenge to avoid an incorrect blend
that could lead to regulatory fines, loss of customer confidence and
damage to equipment. A quick on-site analysis with a portable
mid-infrared based analyzer, such as the Wilks InfraCal Ethanol Blend
Analyzer can help fuel blenders quickly flag out-of-spec product and
ensure the final blend meets specifications.
Lower Resolution Infrared (IR) Spectroscopy Can Provide Higher Performance for Quantitative Biodiesel Measurements
Resolution is often used as a yardstick of instrument performance
in Infrared Spectroscopy.This is especially true when the measurements
are energy limited as they are in the mid-infrared. For example, in
both the European and ASTM standards - EN14078 and ASTM D7371 - for the
determination of biodiesel in diesel fuel, a 4 cm-1 resolution is
specified which is a relatively high resolution. Resolution is important
to qualitatively examine specific components and attributes of a
sample, but quantitative analysis does not always benefit from higher
resolution. In fact, as has been pointed out in the past by Hart and
Griffiths, a lower resolution instrument will actually perform better
for quantitative measurements where absorbance peaks are well defined
and not overlapping1.
Comparison of EN 14078 and ASTM D7371 Infrared
Both EN 14078 and ASTM D7371 methods for
measuring the percent biodiesel in diesel fuel use infrared as the analytical
method and more specifically FTIR (Fourier Transform Infrared) spectrometers;
however, both methods have disadvantages. This White Paper discusses both
methods and how a simplified infrared analysis method incorporates the most
trouble-free portions of each method in a less expensive, easier to operate
and more rugged analyzer than an FTIR spectrometer.
White Papers Soot Meter
Comparing TGA, FTIR and Fixed Filter Infrared Analyzers for Measuring Soot Levels in In-Service Lubricants
soot in diesel engine oil has become more important as soot levels get higher
due to exhaust gas recirculation. As
soot is one of the key indicators for the condition of the oil, diesel engine
maintenance programs performing regular soot checks can realize cost savings by
extending drain periods and reducing used oil disposal.