plating, anodizing, & finishing Q&As since 1989
Determination of chlorides
We are trying to find a suitable method to determine a possible contamination of chlorides inside a sodium dichromate-sulfuric acid pickling bath. The above mentioned bath is producing a high intergranular attack of process control specimens and the presence of chlorides could justify this behaviour. Could someone suggest us a good technique to evaluate small chlorides contents (less than 200 ppm as NaCl)? Ionic chromatography requires a too high dilution of the sample and the relevant error is not acceptable.TAMIRO SALVATORE
ALENIA SPAZIO - TURIN, ITALY
Try using an ion specific electrode.
James Totter, CEF
- Tallahassee, Florida
September 5, 2008
I SUPPOSE YOU USE A SIMPLE TITRATION METHOD(MOHR METHOD) WHERE THE CHLORIDES ARE DETERMINED USING 0.02N SILVER NITRATE USING CHROMATE INDICATOR WHERE THE ENDPOINT ON THE SAMPLE IS A BROWN OR REDDISH BROWN COLOUR WHICH PERSISTS ON CONTINUOUS TITRATION.
CALCULATION AS FOLLOWS:
(T.V*0.02*35450/VOL. OF SAMPLE)g/l
- Mombasa city in Kenya