Lovibond Maxi Direct

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165

MaxiDirect_2c 03/2010

1.1 Methods

Interference levels decrease with increasing sample volume.

Example: Iron interferes above 200 mg/L if a sample volume of 5 ml is used.

At a sample volume of 10 ml the interference level decreases to 100 mg/L.

Table 3:

Interfering substances Interference level using 5 ml of sample

Aluminium 100 mg/l

Arsenate interferes at all concentrations

Benzotriazole 10 mg/l

Bicarbonate 1000 mg/l

Bromide 100 mg/l

Calcium 5000 mg/l

CDTA 100 mg/l

Chloride 5000 mg/l

Chromate 100 mg/l

Copper 100 mg/l

Cyanide 100 mg/l; increase the UV digestion

to 30 minutes

Diethanoldithiocarbamate 50 mg/l

EDTA 100 mg/l

Iron 200 mg/l

Nitrate 200 mg/l

NTA 250 mg/l

Orthophosphate 15 mg/l

Phosphite and

organophosphorus compounds

reacts quantitatively;

Meta- and Polyphosphates do not interfere

Silica 500 mg/l

Silicate 100 mg/l

Sulfate 2000 mg/l

Sulﬁde interferes at all concentrations

Sulﬁte 100 mg/l

Thiourea 10 mg/l

highly buffered samples or

extreme sample pH

may exceed the buffering capacity of the

reagents and require sample pretreatment

Lovibond Maxi Direct - Page 167