TD-550/560 Oil in Water Analyzer fastHEX™ Analysis Method
PN 106737
REV H
TD-550/560 Oil in Water Analyzer
Operation Manual
15
4 FASTHEX™ ANALYSIS METHOD
The fastHEX
TM
method for the TD-550/560 was developed to provide a simple, rapid, accurate, safe
and environmentally friendly eld procedure for the analysis of oil and grease in water. The TD-550/560
measures the oil content of a water sample by measuring the uorescent light emitted by oil that has
been extracted into hexane. Hexane is an inexpensive, non-uorescent, organic solvent that efciently
extracts all types of crude oil, and separates out quickly on top of the water sample.
The fastHEX
TM
method has been in use for several years, and has been eld-proven to give results that
correlate well to US EPA Method 1664 and other ofcial oil and grease methods. The entire procedure,
from taking a water sample to recording results, takes less than 4 minutes. Because the method uses
inexpensive, disposable bottles and cuvettes, solvent waste is reduced to a minimum. Also, unlike
Freon and other halogenated or chlorinated solvents, hexane can be disposed of in most oil and gas
facilities without worrying about physical exposure.
4.1 ALTERNATIVE SOLVENTS
Although the fastHEX
TM
method was originally intended to use hexane, its solvent extraction and
measurement procedures can also be applied to other lighter-than-water solvents (xylene, petroleum
ether, etc.). In addition, the procedure can be modied allowing use of a variety of heavier-than-water
solvents (Vertrel MCA, Ashikleen AK-225, perchloroethylene, etc.). Analysis procedures for lighter-than-
water solvents and heavier-than-water solvents are given in Section 4.2, and Section 4.3, respectively.
4.2 IMPORTANT NOTE REGARDING SOLVENTS
Some solvents, especially Vertrel MCA, Ashikleen AK-225, and chloroform, can damage the
TD-550/560 if left in contact with the plastic parts. If you spill solvents on the case or inside the sample
well, ush the contacted area immediately with isopropyl alcohol and dry the area with a non-abrasive
lab tissue.
Xylenes, toluene, and other aromatic solvents cannot be used as solvents when using the DUV channel
because of interference from uorescence of these solvents.
Always follow safety rules for handling and disposing of solvents.
4.3 CALIBRATING THE ANALYZER FOR FASTHEX
TM
METHOD
NOTE: Some solvents may not be able to dissolve certain oils and hydrocarbons at a 10,000 ppm
concentration. Should this happen, either choose another solvent or choose a lower stock calibration
solution concentration.
The TD-550/560 can be calibrated with a standard solution of oil in extraction solvent. The standard
solution (known oil concentration) is prepared by dissolving a known amount of oil in a known volume
of extraction solvent. The instrument is calibrated by relating measured uorescence response to the
concentration of oil in the standard. This procedure can be used for all extraction solvents.
To prepare a calibration standard
Part 1—Preparing a 10,000 ppm Stock Standard
1. Pipette 1 mL (1000 μL) of oil into a 100 mL volumetric ask that is approximately half full of
clean extraction solvent.
2. Cap the ask and shake it to dissolve the oil.
3. Fill the 100 mL volumetric ask to the mark with clean extraction solvent.
4. Cap and shake the ask to mix.
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