Analysis of TPHd in soil by Portable GC-MS

Field Sampling, Measurement and Sensor Technology
Oral Presentation

Prepared by R. Mohler1, K. Gonzalez2, B. Morlan2, C. Espino Devine3
1 - Chevron ETC, 100 Chevron Way, 50-1271, Richmond, CA, 94801, United States
2 - Chevron ETC, 100 Chevron Way, Richmond, CA, 94801, United States
3 - Chevron ETC, 6001 Bollinger Canyon Rd., San Ramon, CA, 94583, United States


Contact Information: rmohler@chevron.com; 510-242-4939


ABSTRACT



There are several measurement technologies available that
can quantify Total Petroleum Hydrocarbons (TPH) in soils, however, these
methods are spectroscopic methods and are not able to divide the TPH into
gasoline range (TPHg) or diesel (TPHd) range material.  The widely accepted method for environmental
applications for quantifying TPHg and TPHd in soil is defined as solvent extraction
(methanol, dichloromethane or hexane) followed by analysis on a gas
chromatograph with a flame ionization detector (GC-FID) as described in EPA
method 8015.  In order for a method to be
field amenable, there has to be minimal use of solvents and the method would
have to be rapid (i.e. minutes) in order to allow for decisions made in the
field on where to investigate environmental impacts. Portable GCs have recently
become available that are amenable to field use due to rapid analysis time, low
carrier gas consumption, compatibility with headspace measurements, and battery
operation. At Chevron, we recently evaluated the use of a portable GC-MS for
the quantification of TPHd in soils from various sites.  The field set-up, results and lessons learned
will be presented.