January 26, 2020, 06:45:05 PM
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Topic: Cleaning volumetric glassware for TOC analysis.  (Read 400 times)

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Offline javhert

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Cleaning volumetric glassware for TOC analysis.
« on: July 17, 2019, 11:41:46 AM »
Hi. I'm establishing standard procedures for TOC analysis, and I'm aware that glassware cleanliness is of utmost importance here to get accurate results.

I have no issue putting the sample vials on the muffle furnace at 400 °C (as recommended by Standard Methods) to ensure carbon elimination, but the volumetric glassware (pippetes, flasks) used to prepare the calibration standards are another matter since they're too delicate to treat via heat. Which is the best cleaning procedure for those? I hesitate to use any kind of detergent since those are troublesome to rinse on volumetric glassware so I'm expecting some kind of acid mixture that is not too rough on the glass.

Offline chenbeier

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Re: Cleaning volumetric glassware for TOC analysis.
« Reply #1 on: July 17, 2019, 12:36:19 PM »
A bath of propan-2-ol and Potassium hydroxide , rinsing with Di water. will work.

Offline Corribus

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Re: Cleaning volumetric glassware for TOC analysis.
« Reply #2 on: July 17, 2019, 01:33:19 PM »
Base bath can etch glass, so I don't know that I'd be quick to soak my class A analytical glassware in it. For trace metal analysis we clean our analytical glassware with aqua regia. Good old nitric acid or concentrated hydrogen peroxide will also make quick work of organics, so if it were me I'd probably try these first.
What men are poets who can speak of Jupiter if he were like a man, but if he is an immense spinning sphere of methane and ammonia must be silent?  - Richard P. Feynman

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