Environmental Sampling Techniques - Fundamentals of Environmental Sampling and Analysis - page 81

via a rod that passes through the length of the sampler. A thief (grain sampler),
consisting of two slotted concentric tubes, is another commonly used drum sampling
device particularly useful for grain-like material. A sampling trier is used to collect
sticky solids and loosened soils. The trier is usually a stainless steel tube, cut in half
lengthwise with a sharpened tip, which allows the sampler to cut the solid sample. A
trier is relatively easy to use and decontaminate.

Biological Sampling
Biological sampling for chemical residual analysis has very unique and diverse
equipment compared with other environmental sampling processes. Consultation
with an experienced ecologist or biologist is strongly recommended. For instance, in
collecting mammals, trapping is the most common method. Both live and kill trap
methods may be used through commonly used traps such as Museum Special,
Havahart, Longworth, and Sherman traps (EPA, 1997). To collect fish, electrofish-
ing, gill nets, trawl nets, sein nets, and minnow traps are the common methods. In
collecting vegetation samples, samples should be harvested during the growing
season for the herbaceous plants or during the growing or dormant season for woody
plants. For benthic macroinvertebrate samples, both the Petersen and Ekman
dredges can be used as discussed above.

Air and Stack Emission Sampling

There are many direct-reading instruments and types of monitoring equipment that
provide instantaneous (real-time) data on the contaminant levels. Despite this, air
sampling followed by laboratory analysis (off- or on-site) is still required for the
most part of trace level analysis of atmospheric contaminants. Air sampling
equipment is expensive and techniques are complex. Therefore, most of the
compliance (such as source stack emission monitoring) are contracted to
professional stack-testing firms. Since air sampling equipment and sampling
device/media are so diverse, we can only give general discussions herein. Readers in
this field can consult an excellent introductory topic on air sampling by Wight
(1994).
Common air sampling equipments includes (Fig. 4.8) (1) high volume, total
suspended particle (TSP) samplers, (2) PM-10 samplers, (3) High volume PS-1
samplers, (4) personal sampling pumps, and (5) canister samplers. The TSP sampler
collects all suspended particles by drawing in air at 40 cubic feet per minute (cfm)
across an 8 by 10 inch glass-quartz filter. The mass of TSPs is determined by
weighing the filter before and after sampling. The PM-10 sampler collects
particulates with a diameter of 10 m or less from ambient air. PM-10 samplers can

be high volume (40 cfm) or low volume (36 cfm). The high volume sampler uses 8
by 10 inch glass-fiber filter, and the low volume PM-10 sampler collects its sample
on 37-mm Teflon filters.
The PS-1 sampler draws air through polyurethane foam (PUF), or a
combination of foam or adsorbing materials, and a glass-quartz filter at a rate of

m