WEF Discussion Forums : Laboratory Management and Technical Issues : TKN Boling Stones

Tue, 28 Feb 2012 21:29:15 GMT

Is anyone using broken glass instead of boiling stones for TKN analysis? I'm getting lots of "bumping" during my reaction and the manufacture recommends using broken glass pieces. Doesn't seem like a practice a safety officer would approve of.

Tue, 28 Feb 2012 23:14:36 GMT

Hi Jennie,

We use Teflon boiling chips and have no problem with the pumping during digestion.

Wed, 29 Feb 2012 16:54:12 GMT

That is what I have been using. I'm also wondering if possibly the flasks are too full of liquid.

Do you use the Labconco Micro-Digestion system? I'm adding 5 g of soil, 50 mL of standard and 10 mL of TKN-reagent. This is for my MDL study.

When I've added only liquid and less than 50mL I don't get the bumping problem.