Inorganics Analysis continued...
Biochemical Oxygen Demand (BOD)
EMT analyzes more samples for BOD than any other single private laboratory in the country. This parameter is of particular concern to NPDES permit holders or dischargers to a POTW such as the Metropolitan Water Reclamation District of Greater Chicago (MWRD). BOD is an index of the biodegradable organics present in a sample. The analytical method for this test requires that samples for BOD are separated into a series of dilutions and incubated for five days. At the conclusion of the incubation, the oxygen uptake is measured. Dilutions which have used either too much or not enough oxygen are not taken into account for BOD determination for the sample. EMT’s BOD
procedures include a minimum of eight dilutions per sample setting us apart from other labs. Samples for BOD analysis must be kept cool and, optimally, set up for analysis within
six hours of sampling. In no case should samples be held for longer than 24 hours prior to beginning analysis.
Metals Analysis
A variety of methods are available for the determination of metals. Inductively Coupled Plasma (ICP) Emission Spectrophotometers measure the light wavelengths emitted after a digested sample is injected into an argon plasma. Atomic Absorption (AA) Spectrophotometers measure the wavelengths absorbed by a flame as the sample is injected. EMT utilizes two ICPs, one of which is equipped with a Mass Spectrometer (MS) detector. The ICP/MS allows for extremely low, parts per trillion (ppt), detection levels for metals. EMT also utilizes one AA dedicated to Mercury analysis by Cold Vapor. EMT’s large metals capacity
allows our clients a variety of analytical options for metals analysis.
Toxicity Characteristic Leachate Procedure (TCLP)
This test method consists of an extraction process that is necessary to determine whether a material is characteristically hazardous per RCRA. EMT has the capacity to simultaneously extract over thirty samples in our isolated, temperature-controlled extraction room that is dedicated solely to TCLP prep. The TCLP method (SW-846 Method 1311), contains exacting requirements for seemingly mundane details such as temperature, rotator speed, etc. If these details are not regularly checked and documented by the analyst, the entire test method procedure could be called into question. Since the determination of whether or not a waste is hazardous depends upon this procedure, it is critical that all of the method requirements are strictly followed.