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The Home Scientist 023 - Salicylate determination with visual colorimetry, Part I

TheHomeScientist - 2010-04-17

Using iron(III) nitrate to determine salicylate concentration in standardized salicylate solutions and urine.

You can actually use any iron(III) salt, such as ferric chloride, ferric ammonium sulfate, and so on. Concentration is not critical.

Chronology - 2010-04-22

Loved the blooper at the end.. lol...

Deborah Davidson - 2016-11-10

interesting, thanx

Quintinohthree - 2013-09-13

Paracetamol is a phenol itself and codeine is an aryl ether so it might be hydrolysed to a phenol.

Joe S - 2010-04-17

Cool video.

Sillybillydilly - 2010-04-18

@sciocleseus I think that's a great idea... equations and numbers are better pictured, then talking through them showing with a pencil tip

olympicfan2 - 2010-04-17

great intro. yes that stuff is a bit complicated for me.

Sillybillydilly - 2012-04-19

Was cleraning out gmail, and according to doubleu.sciencedirectdotom/science/article/pii/0304416574900713 abstract, in the absence of phos, iron salicylate forms even at pH 9. A standard NaOH digest then ferric would give an unreproducible brown sludge as blank, or simply ferric into random pH unbuffered samples might, and pH 2 would help there, but sulfuric lacks buffer capacity at pH 2, and since salycilate is such a strong complexer, weaker complexers such as low pH citrate might work fine.

av7 - 2010-04-18

that's great. a drug test i can do on my self. Main OTC pain killer i take is 2x 500mg paracetamol/10mg codeine phosphate. Is there a easy urine test i can use for either the paracetamol or the codeine? Thanks

Justin Fedor - 2010-04-17

I highly recommend using a whiteboard or just a piece of paper to write your mathematics and chemical equations down, otherwise it is hard to follow when you just say it. very interesting videos though :)

Sillybillydilly - 2010-04-18

after using NaOH to hydrolyze, it should probably be pH adjusted back, or buffered back with swamping in a buffer that doesn't react with FeIII (no citrate, phosphate.. actually simply hitting it with 10% sulfuric should bring the pH near 1-2, where the reaction happens. Above pH 3 to 5 (depending on ferric concentration) rust hydroxide precipitates no matter what... so the higher than 2 pH citrate and phosphate buffers wouldn't work even if they didn't react with ferric..