The Mega Sampler for
Extensive Investigation of Organic
Pollutants in Water
F. M. MIDDLETON, Chief, Advanced Waste Treatment
H. H. PETTIT, Laboratory Mechanic, Chemistry and Physics
. A. ROSEN, In Charge, Organic Contaminants Unit, Chemistry and Physics
Robert A. Taft Sanitary Engineering Center
U. S. Public Health Service
Cincinnati 26, Ohio
Because of tastes and odors in water, fish kills, interferences with water
treatment, and interferences with industrial uses, the need became apparent
shortly after World War II to extend our analytical procedures to attempt to
measure some of the trace organic components that maybe responsible for the
damages noted. The greatly increased population and rise in industrial production along with the manufacture of many new and biologically resistant
materials lent further impetus to the need for better ways of testing.
One of the techniques developed to meet the need for recovering and
measuring small amounts of organic contaminants was the carbon adsorption
method. The use of the carbon procedures which have been principally developed by the Public Health Service began in 1949 (1,2). The unique ability
of activated carbon to adsorb organics from solution is utilized to collect the
trace quantities of materials from river wastes and drinking waters. Once the
materials have been adsorbed onto the carbon, they are later removed by extraction with chloroform followed by an alcohol extraction. Distillation of
the solvents then leaves the residues of interest; these can be studied in a
variety of ways.
The early sampling equipment consisted of a three-in. diameter iron
pipe three ft long containing sand for a prefilter followed by a similar pipe
holding carbon. Granular carbon was used and several types were tested to
find the ones that would be best, both from the standpoint of collection of the
sample and later extraction. The iron pipe holding carbon was later replaced
with glass pipe three ins. in diameter by 18 ins. long. The technique has
been used in various forms and details have been written previously. Extraction of the carbon from the smaller units was made in a large-scale laboratory
Soxhlet extractor.
These early methods served well to explore the feasibility of the sampling
methods and to determine the character of certain organic pollutants in
water. The equipment is usable on a practical scale and it is possible to
collect fractional gm or gm quantities of material, but the collection of
large amounts of material is not practical.
It soon became apparent that larger amounts of material would be needed
both for analysis and for possible physiological studies which may be desired.
Also, it is quite useful to be able to sample a large volume of water in a
short time since this could not be done with the smaller sampling unit. The
decision was made to build a Mega Sampler and a companion extractor so
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