11-Lab - Available Chlorine

Andreia Bianchini Author

12/13/2017 Added

24 Plays

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Lab demonstration about use of chlorine strips.

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[00:00:04.944]Welcome to Science of Safe Food.
[00:00:06.854]Today we're gonna talk about the difference
[00:00:10.005]between dirty sanitation bucket water
[00:00:12.898]and clean sanitation bucket water
[00:00:14.952]and how the dirty sanitation bucket water affects
[00:00:18.056]the ability of the sanitizer,
[00:00:19.860]in this case chlorine,
[00:00:21.720]to effectively clean the surfaces
[00:00:23.634]that you're applying it to.
[00:00:25.355]So, when we're doing cleaning
[00:00:27.869]and we're testing our cleaning kits,
[00:00:29.694]there's two different ways
[00:00:31.011]to evaluate if there's chlorine available
[00:00:34.888]in the solution in order to properly clean the surfaces
[00:00:38.526]and the first type is a solution test kit
[00:00:41.708]and this uses a series of solutions
[00:00:43.483]that goes through and tests the total chlorine
[00:00:45.690]that's available in the sanitation bucket water
[00:00:49.036]and there's also these test strips available
[00:00:52.008]on the market
[00:00:52.989]and the difference is is these test strips
[00:00:55.256]they're very easy to use
[00:00:57.419]but they're not very effective.
[00:01:00.373]They're not gonna tell you the exact amount
[00:01:01.765]of chlorine that you have available
[00:01:03.378]but they are out there if you did want to use them
[00:01:06.421]but today we're gonna set those aside
[00:01:08.957]and we're gonna take a look
[00:01:10.018]at a solution test kit
[00:01:12.318]and we're gonna go through this test kit
[00:01:13.879]and show you how it works
[00:01:15.488]and we're gonna show the difference
[00:01:16.894]between the total chlorine that's available
[00:01:18.921]between a clean sanitation bucket water
[00:01:21.230]and a dirty sanitation bucket water.
[00:01:23.975]So, to begin, we're gonna go ahead
[00:01:26.076]and open up our clean sanitation bucket water solution here.
[00:01:30.471]We'll set this one aside.
[00:01:34.648]Get that out of there.
[00:01:38.457]And we'll set the lid aside here
[00:01:40.121]and we're gonna start with our first solution
[00:01:42.061]and our first solution is a sodium iodide
[00:01:45.288]and what this is gonna do
[00:01:46.305]is it is gonna bind to the chlorine
[00:01:48.520]that's in the sanitation bucket water.
[00:01:52.075]And we're go ahead
[00:01:54.515]and we are gonna add five drops of this to our solution.
[00:02:11.210]And then we're gonna go ahead
[00:02:12.147]and give that a little bit of a swirl
[00:02:14.152]just to mix it up good
[00:02:16.054]and then we're gonna go to our next solution
[00:02:19.002]which is a phosphoric acid
[00:02:21.282]and this is just gonna go into the solution.
[00:02:23.175]It helps activate the solution
[00:02:24.748]and also helps lower the PH a little bit.
[00:02:32.405]And we're gonna add five drops of this as well.
[00:02:42.919]And once again we'll give it a little bit of a swirl
[00:02:46.303]just to mix everything up.
[00:02:49.659]Now we're gonna add the next solution
[00:02:53.542]which is the starch indicator
[00:02:56.704]and what this does
[00:02:57.933]is it's going to determine
[00:03:01.022]if there's any bound chlorine from the potassium iodide
[00:03:04.323]from the first solution
[00:03:06.509]and as we add this, if there's any bound chlorine,
[00:03:11.955]or total chlorine,
[00:03:12.934]we're going to see that by the solution changing
[00:03:15.058]a dark purple color
[00:03:17.830]and we're gonna add five drops of this as well.
[00:03:24.069]And I really like this
[00:03:25.609]because it's very visual
[00:03:27.403]and you can see that color change
[00:03:29.168]which helps you know that the solutions
[00:03:30.902]are working correctly.
[00:03:32.443]Give it a little bit of a swirl
[00:03:34.018]and as you can see there
[00:03:35.858]we did change black or purplish in color
[00:03:39.238]therefore there is some chlorine
[00:03:40.747]within this solution.
[00:03:42.780]And then finally, let me put that cap back on there,
[00:03:47.045]we're gonna go to our last solution
[00:03:49.437]and this is the sodium thiosulfate
[00:03:53.527]and we're gonna take this
[00:03:55.315]and we're gonna add this drop by drop
[00:03:57.465]and as we do this
[00:03:59.219]we're gonna count the number of drops
[00:04:00.975]and this is gonna help us calculate
[00:04:02.418]the amount of total chlorine
[00:04:03.725]that's within our sanitation bucket water.
[00:04:07.818]So, we'll go ahead and remove that cap there.
[00:04:11.990]I'll take this back up.
[00:04:13.837]Make sure you guys can see that on the video.
[00:04:17.364]So, we're gonna go ahead and count these,
[00:04:18.998]so one, two,
[00:04:22.603]three, and we'll go ahead and give that a little bit
[00:04:25.082]of a swirl.
[00:04:28.084]Four, five, six.
[00:04:32.836]Looks like we're starting to maybe change a little bit.
[00:04:35.154]We'll see what seven does here.
[00:04:38.843]Little bit of a change.
[00:04:40.431]Let's try eight.
[00:04:42.741]And there we go.
[00:04:44.083]So, based on the way this kit works,
[00:04:47.683]it took eight drops in order to change the color
[00:04:50.348]of the solution back to clear.
[00:04:52.104]We're back to its original color.
[00:04:54.009]And so, what that means
[00:04:54.851]is each one of those drops
[00:04:56.097]represents 10 parts per million total chlorine,
[00:05:00.068]so based on this, the eight drops equals 80 parts
[00:05:03.109]per million total chlorine
[00:05:04.145]in this clean sanitation bucket water solution.
[00:05:07.331]So, now that we've determined
[00:05:09.003]what our sanitation bucket water solution
[00:05:11.715]is for the clean one at 80 parts per million total chlorine,
[00:05:15.230]now we're gonna take a look at what the dirty solution
[00:05:17.868]comes in at.
[00:05:21.153]And to do the dirty solution
[00:05:23.130]it's gonna be the exact same process
[00:05:25.567]as the clean solution,
[00:05:27.281]so we'll go through this a little bit more quickly.
[00:05:33.095]So, we'll go ahead and take the cap off here.
[00:05:38.616]And we'll grab that first solution once again,
[00:05:41.327]the potassium iodide,
[00:05:43.483]and we're gonna add five drops once again.
[00:05:55.991]And give it a little bit of a swirl.
[00:06:02.387]And then you're gonna go ahead and add our phosphoric acid.
[00:06:12.328]Five drops of that
[00:06:23.417]and swirl it once again.
[00:06:28.093]And then we're gonna go ahead and have that starch indicator
[00:06:33.040]and once again this should turn
[00:06:34.771]a dark purple to blackish color
[00:06:37.543]if there's some chlorine present.
[00:06:50.133]And as you can see there
[00:06:50.966]it did change just like the clean solution
[00:06:53.659]and now once again we're gonna go ahead
[00:06:55.200]and we're gonna count the number of drops
[00:06:56.592]of the final solution
[00:06:58.630]to see what our total parts per million is
[00:07:02.502]within in the dirty sanitation bucket water.
[00:07:11.869]There's three.
[00:07:18.339]Four, five.
[00:07:22.490]Looks like we're gonna maybe be at looks like about six.
[00:07:28.169]So, in this situation
[00:07:31.416]with the dirty solution
[00:07:33.641]we can see that it only took six drops,
[00:07:36.023]so based on our previous calculations
[00:07:39.089]it's only at 60 parts per million
[00:07:41.231]and this is extremely important
[00:07:43.284]because this shows
[00:07:44.750]that the dirty sanitation bucket water
[00:07:47.008]is not going to be as effective
[00:07:48.995]as the clean sanitation bucket water.
[00:07:51.185]It's also important to note
[00:07:52.096]that these solutions were made at the exact same time
[00:07:54.716]at the same parts per million,
[00:07:56.243]so it also shows that over time
[00:07:58.545]especially in the dirty sanitation bucket water
[00:08:01.113]that the total chlorine that's available
[00:08:04.274]in order to clean the surfaces effectively
[00:08:06.238]is going away and so, it's very important
[00:08:09.110]that you always use a fresh, clean solution
[00:08:11.587]when cleaning your tabletop surfaces
[00:08:14.513]and your food preparation areas.

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11-Lab - Available Chlorine

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