PART D - D-1319 STANDARD TEST METHOD FOR HYDROCARBON
TYPES IN LIQUID PETROLEUM PRODUCTS BY FLUORESCENT
INDICATOR ADSORPTION
Requirements and Warnings.
Isoamyl Alcohol Warning - Flammable. Health hazard.
Isopropyl Alcohol Warning - Flammable. Heath hazard.
Pressuring Gas Warning - Compressed gas under high pressure.
Acetone Warning - Flammable. Heath hazard.
Environmental precautions for this test method are to clean up all spills immediately. Dispose of
hazardous materials and hazardous waste IAW laboratory SOP. Report all hazardous material and
hazardous waste spills immediately. Be familiar with, and know the location of MSDS for all hazardous
materials present in the workplace.
Apparatus for this test method consists of absorption columns, zone-measuring device, ultraviolet light
source, electric vibrator, hypodermic syringe, and regulator.
Sampling requirements are to get a sample according to procedures in practice D 4057. Store the
sample until ready for analysis at 4C.
Testing procedure.
Freely suspend the column from a loose-fitting clamp placed immediately below the spherical joint of the
charger section. While vibrating the column along its entire length, add small increments of silica gel
through a glass funnel into the charger section until the separator section is half full. Stop the vibrator
and add a 3 to 5-mm layer of dyed gel. Start the vibrator and vibrate the column while adding more
silica gel. Continue to add silica gel until the tightly packed gel extends 75 mm into the charger section.
Wipe the length of the column with a damp cloth while vibrating the column. This aids in packing the
column by removing static electricity. After filling is complete, vibrate the column for about 4 minutes.
Attach the filled column to the apparatus assembly in the darkened room or area, and when a
permanently mounted meter rule is used, fasten the lower end of the column to the fixed rule with a
rubber band.
Chill the sample and a hypodermic syringe to 2 to 4C. Draw 0.75 0.03-ml of sample into the syringe
and inject the sample 30 mm below the surface of the gel in the charger section.
Fill the charger section to the spherical joint with isopropyl alcohol. Connect the column to the gas
manifold and apply 14 kPa gas pressure for 2.5 minutes to move the liquid front down the column.
Increase the pressure to 34 kPa gage for another 2.5 minutes and then adjust the pressure required to
give a transit time of about 1 hour. Usually a gas pressure of 28 to 69 kPa gage is needed for gasoline-
type samples and 69 to 103 kPa gage for jet fuels. The pressure required will depend on the tightness of
packing of the gel and the molecular weight of the sample. A transit time of 1 hour is optimum; however,
high-molecular weight samples may require longer transit.
Avoid touching the column with the hands during this operation. Also, direct exposure to ultraviolet light
can be harmful, and operators should avoid this as much as possible, particularly with regard to their
eyes.
After the red, alcohol-aromatic boundary has advanced 350 mm into the analyzer section, make a set of
readings by quickly marking the boundary of each hydrocarbon-type zone observed in ultraviolet light in
the following sequence. For the nonfluorescent saturate zone, mark the front of the charge and the point
where the yellow fluorescence first reaches its maximum intensity; for the upper end of the second, or
olefin zone, mark the point where the first intense blue fluorescence occurs; finally, for the upper end of
the third, or aromatic zone, mark the upper end of a reddish or brown zone. With colorless distillates, the
alcohol-aromatic boundary is clearly defined by a red ring of dye. However, impurities in cracked fuels
often obscure this red ring and give a brown coloration, which varies in length, but which shall be
counted as a part of the aromatic zone; if no blue fluorescence is present, the brown or reddish ring shall
be considered a part of the next distinguishable zone below it in the column. If boundaries have been
marked off with index clips, record the measurements.
When the sample has advanced another 50 mm down the column, make a second set of readings by
marking the zones in reverse order as described in the previous step so as to minimize errors due to the
advancement of boundary positions during readings. If the marking has been made with a glass-writing
1-5
QM 5181
Previous Page
