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1. Introduction
1.1 The L100 PeCOD
®
Soluble COD Analyzer
Thank you for purchasing the L100 PeCOD
®
COD analyzer. The L100 PeCOD
®
COD analyzer has been specifically
designed for quantifying the organic content using a patented photo-electrochemical technique to determine the
Chemical Oxygen Demand (COD). No toxic reagents are required, making this technique an environmentally
friendly method for COD and rapid screening of Biological Oxygen Demand (BOD).
MANTECH products are manufactured, tested and calibrated to meet published standard specifications under
our strict quality assurance guidelines. The main components consist of the sensor, electrode block, light source,
and three ports (one each for sample, blank solutions and waste).
Please read this manual thoroughly before operating your L100 analyzer.
The L100 analyzer is designed to be used only by properly qualified and trained personnel.
1.2 Theory of Operation Mechanism
Photocatalytic Oxidation
The PeCOD
®
L100 analyzer employs a unique patented technology that can directly measure photocurrent
originating from the oxidation of organic species contained in a sample. The core of the technology is the PeCOD
®
sensor, which consists of a UV-activated nano-particulate TiO
2
(titanium dioxide) photocatalyst coupled to an
external circuit.
The sample is introduced into a microcell containing the sensor. The TiO
2
is irradiated by UV light, and a potential
bias is applied. The UV light creates a photo hole in the TiO
2
sensor with a very high oxidizing power (3.1V) and
organic contents in the cell are oxidized (the chemical potential of the dichromate method is only 1.6V). The
PeCOD
®
COD analyzer exhaustively oxidizes organics, and counts the electrons that are liberated to provide a
direct measure of equivalent COD.
The following figure illustrates the photo-electrocatalytic process involved in the analytical signal generation.
