High quality Chlorinated Pesticide and Polychlorinated
biphenyl (PCB) analysis is performed using high resolution
gas chromatography / electron capture detection (GC/ECD)
and is a quantitative analytical technique used for the
determination of chlorinated hydrocarbons in extracts of
tissue, water, and sediment. Method
Detection Limits using this technique are very low (<
0.2 ng/dry g for sediment, <5 ng/L for water, and <4 ng/wet
g for tissue).
The GC is temperature programmed, operated in split mode,
and carrier flow is regulated by electronic pressure control.
The capillary column is a Supelco SPBTM-5 (30
m long by 0.25 mm ID and 0.25 mm film thickness) or
equivalent. Dual auto-injectors, columns and detectors are
used, and the data acquisition system is by Hewlett Packard
Chemstation software.
A sample batch is analyzed as an analytical set that includes
samples along with the following specified quality control
samples: method-blank, matrix-spike, duplicate, matrix-spike
duplicate, and standard reference material.
A calibration curve is established by analyzing 2 mL
each of five calibration standards (analyte concentrations
ranging from 0.005 to 0.200 mg/mL) and fitting the
data to a quadratic equation. Calibration check standards
are interspersed throughout an analytical batch in order
to ensure the instrument’s integrity. An Aroclor mixture
is used as a retention index solution for individual PCBs
not found in the calibration solution, and individual PCB
retention times are determined based on pattern recognition.
Analyte concentrations are determined using the internal
standard method and analyte concentrations are corrected
for surrogate recovery.
