i remember reading recently that it was discovered that a lot of studies regarding microplastics are likely wrong. because nitrile gloves used to operate in the laboratory gives off microplastics, so there is basically no uncontaminated samples.
so, always check your presumably “clean” samples too!
Is lab grade distilled water more guaranteed to be neutral pH? Because I tested some random distilled water from walmart and it was like 5.5. I then went down a rabbit hole and learned that distilled water is so pure that it just sucks up carbon from the air.
Not only the CO2, but also the glassware you put the water in for measuring can very significantly alter the pH. Some scientists I know systematically screened different, presumably clean, containers because of this effect before progressing with their experiments.
it will vary, just after distillation (or RO/ion exchange) it should be closer to 7 then it goes down as carbon dioxide gets absorbed. that’s why it’s buffered everywhere where it matters
i heard a story about varnish factory that failed quality checks after one old guy got fired, he was a smoker and used to spit in the main reactor. some enzyme from saliva made it shinier
I had a labmate who insisted on ph testing distilled water. Not because he was concerned about contamination, but because it was part of the ritual.
I used to do a similar ritual, and it was really reassuring. Might be an autistic thing for me though lol.
i remember reading recently that it was discovered that a lot of studies regarding microplastics are likely wrong. because nitrile gloves used to operate in the laboratory gives off microplastics, so there is basically no uncontaminated samples.
so, always check your presumably “clean” samples too!
You might, or might not be surprised to hear I tested for variables like that regularly lol.
Is lab grade distilled water more guaranteed to be neutral pH? Because I tested some random distilled water from walmart and it was like 5.5. I then went down a rabbit hole and learned that distilled water is so pure that it just sucks up carbon from the air.
Not only the CO2, but also the glassware you put the water in for measuring can very significantly alter the pH. Some scientists I know systematically screened different, presumably clean, containers because of this effect before progressing with their experiments.
We had a distiller in the department. We’d roll over a cart fill a carboy.
it will vary, just after distillation (or RO/ion exchange) it should be closer to 7 then it goes down as carbon dioxide gets absorbed. that’s why it’s buffered everywhere where it matters
maybe it introduces some critical contaminant (many such cases)
“We switched brands of litmus paper and now everything’s in shambles!”
i heard a story about varnish factory that failed quality checks after one old guy got fired, he was a smoker and used to spit in the main reactor. some enzyme from saliva made it shinier