Simple and rapid method for the determination of the total of C-7-C32
hydrocarbons in water has been described. Water samples are extracted
with n-pentane (n-pentane: water = 1 : 50) in a graduated flask; extra
ction is followed by gas-chromatography analysis using flame ionizatio
n detector. The yields for hydrocarbon recovery are high, usually in e
xcess of 90%. The extraction procedure is very versatile; water contam
inated with benzene and higher molecular weight hydrocarbons from gaso
line, kerosene, diesel oil, and very heavy petroleum products (engine
oil, mazout) can be handled. The limit of determination is 3 mug l-1 f
or the individual hydrocarbon and 10-40 mug l-1 for the petroleum prod
uct. The method has been tested extensively for the samples of ground
water from the areas subjected to leaks of petroleum products.