S pe c t r a l S e n s o r s by C a r l Ze i s s

O N -L I N E A N A L Y S I S O F A R O M A T I C
H Y D R O C A R B O N S IN P R O C E S S W A T E R
INT R ODUC T ION

Aromatic Hydrocarbons s uch as benzene and its derivatives, toluene and xylene often referred as B T X
are us ed as s tarting materials in a multitude ofproducts from pharmaceuticals , dyes , polymers toagrochemicals .
T hes e aromatics are known to caus e health effects
from chronic expos ure and even benzene is lis ted as acancer caus ing s ubs tance. In production proces s es
cooling water and condens ed water can becomecontaminated with thes e compounds . It is therefore
neces s ary to have reliable and fas t methods todetermine and control the amount of thes e compounds
as well as effective methods for treatment and removal.
F igure 1: B T X s olvents

G as chromatography is the mos t commonly us edmethod for meas urement. However, there is demand
for alternative methods utilis ing fas t on-line analys iswith lower running cos ts .

T HE ME T HOD
Aromatic hydrocarbons s how good abs orption
characteris tics in UV -V IS region due to the high levelof conjugated bonds pres ent. F igure 1 gives an example
of different concentrations of a benzene, toluene, xylene
mixture in water.
A method us ing abs orbance characteris tic of aromatics
in the region 190–300 nm was developed to meas ure
thes e compounds in the ppm range.
A P LS algorithm is us ed to determine the concentrationof individual and total aromatics .
F igure 2: LabView screenshot

株式会社

スペクトラ・コープ〒164‑0011 東京都中野区中央4‑4‑5第一小林ビル
Tel:03‑5328‑2858 Fax:03‑5328‑2859
URL http://www.spectra.co.jp

Spectral Sensors by Carl Zeiss

THE SYSTEM
The industrial diode array system MCS 500 UV based on the established ZEISS MCS polychromator technology
provides the spectral information in the UV range required for the developed method.
High sensitivity, high wavelength stability and low straylight guarantee excellent reliability of the determined values.
Pre-aligned flow cell, 2-channel plug-in multiplexer to measure two streams or sample/reference, industrial standard
outputs (RS 422, 4-20 mA) and an easy-to-use on-line software package complete the system.
Systems can be cascaded and controlled via one Host PC to measure compounds in different streams.
THE SOFTWAREThe DM1 software package is designed to run under WINDOWS®NT and includes the PLS/IQ module from
GALACTIC to work with any PLS model designed under GRAMS 5.
The programm allows to display the results of up to 4 channels including the measured absorbance spectra.
Concentrations of the compounds can be displayed, saved and/or sent via analog output.
Digital controlled devices like valves, shutter etc. to switch streams or references can be included in the automatedsignal processing.
THE BENEFITS♦♦♦
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Analysis and response time greatly reduced
Fast and continuous monitoring
Established and proved system and method
High reliability, low maintananceEasy to use software
Speed and full spectrum advantage of photodiode array detection
Possibility to combine systems to monitor various streams
Fiber optics allow flexibility in installation and location of the system

SYSTEM SPECIFICATIONS
Wavelength range
Wavelength resolution
Wavelength reproducibility
Measurement time
PC Interface
Distance between PC and System
Analog output (4 – 20 mA)
Optical Fiber (Probes-System)
Housing

Carl Zeiss
Spectral Sensors

200 – 620 nm (190–1020 nm optional)
0,8 nm/diode (2,4 nm Rayleigh)< 0,05 nm
< 2s
RS422
up to 80 m with standard cable
Up to 2,5 km with waveguide transmission
4 channels (standard)
NI PC ISA card
Quartz, 600 µm core, SMA
Maximum distance 10 m
19” slide-in rack
19” protective housing

D-07740 Jena
Telefon:(03641)64 33 85
Telefax:(03641)64 33 11
E-Mail:info.spektralsensorik@zeiss.de
Internet:
http:\\www.zeiss.de