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• At the end of measurement, the instrument directly displays concentration in mg/L (ppm) of
anionic surfactants (MBAS) as SDBS on the LCD.
CONVERSION FACTORS
The anionic detergent content is expressed as mg/L of SDBS .
Convert the reading to mg/L (ppm) of a different anionic detergent concentration (DX) of known
molecular weight (MW
DX
), as follows:
Reading (mg/L SDBS) x MW
DX
348.48
DX (mg/L)
=
INTERFERENCES
Cationic
surfactants
negative
interference
Absorption particulate matter
negative interference
Sulfide
negative
interference
Organic sulfates, sulfonates
positive interference
Strong oxidants (Cl
2
, H
2
O
2
, S
2
O
8
2‑
, etc.)
negative interference
Highly buffered samples or with extreme pH may exceed the buffering capacity of the reagent: pH
should be adjusted between 4 and 9 with diluted NaOH for acidic samples or with diluted HCl for
alkaline samples, prior to addition of the reagent.
MEASUREMENT PROCEDURE