Soap Contamination Remediation -- Glass Cleaning

[A Single Step]

MHRB was extracted using citric acid, basified with NaOH and then pulled with xylene. The mixing beaker and new separatory funnel were cleaned with dish soap. Xylene from previous step and 200 mL of 2 pH citric acid solution were added to the sep funnel and shaken vigorously. The mixture formed what was first though to be an emulsion, and later realized was probably soap suds.

There is one thread on the nexus about this and the recommendation there was to discard. Is there anything to be done to resolve the issue aside from start over? Fortunately, there's another 125 g of MHRB in stock.

The aforementioned thread also suggested rinsing glassware with acetone or IPA after washing to remove soap residue. One would think rinsing with really hot water would suffice. How do you (or SWIY) clean the glassware?

 

[A Single Step]

Now that it's settled.

 

[Bisy]

yhat looks like it may be dmt precipitate to me. why would soap sink and float in the aq.?

 

[A Single Step]

yhat looks like it may be dmt precipitate to me. why would soap sink and float in the aq.?

Thanks for talking sense to paranoia. Soap bubble do not sink or float around. The sep funnel was left outside in the cool night air and this morning there's a fluffy white layer between Aq and NPS. Looks like dem deems.

 

[downwardsfromzero]

Looks like a perfectly normal emulsion to me.

The cloudiness in the aqueous layer might also be calcium citrate, if you used tap water. The brown crud looks like some fine MHRB particulates got carried over in the A/B but considering it's now stuck to the inside of your sep funnel (aha!) that's no longer a problem - other than having to clean your sep funnel, of course. Perhaps an ultrasonic cleaning bath is on your shopping list?

Glassware for detergent analysis is routinely washed with 2N HCl.

 

[IridiumAndLace]

I can't speak to your extraction, but I normally wash my glassware by rinsing it in sequence:

1. Acetone
2. Tap water
3. Distilled water

If I'm going to use the glassware again right away and need it dry in a hurry, I'll rinse the remaining drops of distilled water out with a bit more acetone.

For particularly stubborn gunk, I'll scrub the glassware with a paper towel and a bit of Bon Ami powder, followed by copious amounts of tap water, then a rinse with distilled water followed by acetone. I like Bon Ami because it's scrubby and rinses off very clean; we'd use it in the microbiology lab to clean slides. (It's also my go-to scrubby soap in the kitchen too - love it on stainless steel!) Fair warning, it will scratch glass if you scrub hard enough. Maybe try the 1886 Formula if that's a concern for you?

Also, for what it's worth, I have a note in my lab notebook that MHRB may have a sudsy effect by itself. I discovered this after a bag of hydrating MHRB powder leaked into the bowl it was sitting in. When I went to rinse it out, the residue had a soapy, sudsy quality. Some part of me thinks that willow bark has a similar soapy effect; my note mentions, "must be a bark thing." Not sure that holds up through being acidified and basified, but it's a thought anyway.

 

[Bisy]

I can't speak to your extraction, but I normally wash my glassware by rinsing it in sequence:

1. Acetone
2. Tap water
3. Distilled water

If I'm going to use the glassware again right away and need it dry in a hurry, I'll rinse the remaining drops of distilled water out with a bit more acetone.

For particularly stubborn gunk, I'll scrub the glassware with a paper towel and a bit of Bon Ami powder, followed by copious amounts of tap water, then a rinse with distilled water followed by acetone. I like Bon Ami because it's scrubby and rinses off very clean; we'd use it in the microbiology lab to clean slides. (It's also my go-to scrubby soap in the kitchen too - love it on stainless steel!) Fair warning, it will scratch glass if you scrub hard enough. Maybe try the 1886 Formula if that's a concern for you?

Also, for what it's worth, I have a note in my lab notebook that MHRB may have a sudsy effect by itself. I discovered this after a bag of hydrating MHRB powder leaked into the bowl it was sitting in. When I went to rinse it out, the residue had a soapy, sudsy quality. Some part of me thinks that willow bark has a similar soapy effect; my note mentions, "must be a bark thing." Not sure that holds up through being acidified and basified, but it's a thought anyway.

i believe i have observes soapy sudsy behavior with mhrb as well, but its never a white foamy emulsion looking effect. its always more of a light to medium brown i guess.

 

[downwardsfromzero]

A wide range of plants contain substances which have this effect, being termed 'saponins'. Saponins themselves are a broad-ranging collection of organic chemical compounds; I wouldn't be at all surprised if MHRB contained triterpenoid saponins. This group of compounds are fairly common and occur in some closely-enough related species.