What stack test method is used to sample diallyl phthalate (DAP)?

Diallyl phthalate (DAP) is a nearly colorless liquid, insoluble or limited solubility in gasoline.  It is soluble in most organic liquids.  It is a primary plasticizer for most resins.  It is a polymerizable monomer which will polymerize with heat and catalyst into a clear, hard, insoluble polymer.

Diallyl phthalate has a boiling point of 158-165 C ( 4 mm) and a vapor pressure of 1.5 mm at 150 C.  Diallyl phthalate is therefore defined as a “semi-volatile.”

SW-846, Method 0010 would be the best selection for a method to extract and quantitate diallyl phthalate from a source.  Since diallyl phthalate is not a traditional semi-volatile using Method 0010, I would suggest, as does the method, performing several laboratory evaluations of spiking known concentrations of DAP on clean, certified XAD-2 cartridges.

First set of experiments would to evaluate the extraction efficiency of XAD-2 releasing the DAP to the extraction solvent.  This experiment would require spiking three (3) XAD-2 cartridges with neat DAP (spiking in the center of the XAD-2 resin bed) at concentrations expected from the source.  You would then perform a normal Soxhlet extraction to determine the system efficiency (remember, the XAD-2 resin bed must also be spiked with the normal laboratory surrogates).  The recovery of the DAP from the XAD-2 cartridges must fall within Method 0010 surrogate recovery limits of 50-150 %.

The second set of experiments would involve spiking three (3) cartridges with the same level of DAP as used in the extraction experiment.  This time, the XAD-2 is challenged with clean, ambient air for the same sampling period as Method 0010 sampling time would require.  The XAD-2 cartridges would be recovered in the same manner, soxhlet extracted and analyzed by GC/MS.  Once again, the recovery limits would be 50-150 %.

During this experiment, you are determining whether the DAP will remain on the XAD-2 resin bed during sampling and whether there is any possibility of degradation of the DAP during sampling.

On the ambient side, we have excellent recoveries of DAP using combination of polyurethane foam (PUF)/ XAD-2 cartridges for trapping phthalates from ambient air.  Our laboratory experiments show an average of 92 % recovery for most of the phthalates.  Based upon that experience, I feel that SW-846, Method 0010 will be adequate for DAP.

(However, the phthalates can be a background problem for XAD-2 resin.  I would therefore suggest that you clean, certify the resin to show that you do not have phthalates as background concentration on the resin, but use the resin only once.  Use clean resin each time to minimize possible problems.)