Question about PH Meter Storage Solution

Question about PH Meter Storage Solution

Post by Paul S. Remingto » Sun, 12 Oct 2003 10:55:18



    Hey there everyone!

    I recently purchased a PH meter and after I got it they stated that the
electrode should be stored in a storage solution.  Problem is, I'm getting
my juice from a vineyard and need to use the PH meter tomorrow.

    Is there are solution I can prepare or anything I can do to store this
electrode safely until I can get the proper storage solution?

    Any help would be greatly appreciated.  Thanks!

    -Paul

 
 
 

Question about PH Meter Storage Solution

Post by J Dixo » Sun, 12 Oct 2003 11:21:31


Paul,
     I have heard of people using the buffer solution to store the probes
in. I dont know what the plus/minuses of this are however, but it must be
better than storing them dry.
John Dixon


Quote:
>     Hey there everyone!

>     I recently purchased a PH meter and after I got it they stated that
the
> electrode should be stored in a storage solution.  Problem is, I'm getting
> my juice from a vineyard and need to use the PH meter tomorrow.

>     Is there are solution I can prepare or anything I can do to store this
> electrode safely until I can get the proper storage solution?

>     Any help would be greatly appreciated.  Thanks!

>     -Paul


 
 
 

Question about PH Meter Storage Solution

Post by Tom » Sun, 12 Oct 2003 11:43:45




Quote:
>     Hey there everyone!

>     I recently purchased a PH meter and after I got it they stated that
the
> electrode should be stored in a storage solution.  Problem is, I'm getting
> my juice from a vineyard and need to use the PH meter tomorrow.

>     Is there are solution I can prepare or anything I can do to store this
> electrode safely until I can get the proper storage solution?

pH buffer should be safe enough for the time being, but 4N KCl solution is
what's recommended for storage.  That's pretty close to saturated IIRC.

BTW, I've noticed that something tends to grow in the storage solution, so I
boil it and immerse the electrode while the solution is still hot when I put
it away for the time being.

Tom S

 
 
 

Question about PH Meter Storage Solution

Post by se » Mon, 13 Oct 2003 10:56:47


. The most critical part of the electrode is the tip at the bottom.
This round part is actually a membrane that has small pores. If these
pores become plugged, the electrode will not work or will work poorly
(slowly or irreproducibly). Never wipe the bottom of the electrode
with a cloth or anything. Don't touch it with your fingers. Clean it
by by rinsing or soaking it. A small squirt bottle is handy for
rinsing. [Please note: The instructions that come with the meter
instrucy you to dry the tip with a soft tissue during calibration.
There is no need to do this and you risk damaging the tip.]
2. What can plug the pores? Must or wine or wort or beer can all plug
the pores so it is a good idea to rinse your electrode after each use.
Colored buffer solutions may also plug the pores if the electrode is
stored in them. [The buffer capsules make uncolored buffers.]
3. You can tell if the pores are plugged if your meter operates slowly
and/or the reading is inconsistent.
4. If the electrode is left out and the tip is not kept wet, then you
may need to soak the electrode for several hours in storage solution
(best) or buffer solution. The soaking simply opens up the pores. You
should not soak or store the electrode in distilled water. If you have
nothing else, tap water is okay and much better than distilled water.
5. The German pH meter is not a sealed (gel filled) electrode such as
that on the Checker [Gel filled electrodes are good for pocket meters
where durability is an issue but are otherwise inferior to a
refillable electrode.] The electrode must be filled with reference
solution (KCL) occasionally. [It is a double junction electrode which
means you do not need AgCl/KCl as in a single junction electrode.] The
formation of salt KCl crystals is normal and not a concern. However,
the hole should not be plugged during use. When it becomes plugged,
simply wipe off the crystals or use a toothpick to open the hole.
6. The electrode need not be full to operate properly, but the lower
part where the pores are, must be full. Generally, I only refill if it
gets more than half empty.
7. Store the electrode in the Storage solution. The electrode comes
with a plastic cover for the tip. Simply put a little storage solution
in the cover, insert the electrode, and it will keep well.
 
 
 

Question about PH Meter Storage Solution

Post by Glen Duf » Mon, 13 Oct 2003 18:40:47


Paul,

The instructions I got with my Hanna pHEP unit is to store it in storage
solution or pH 7.01 calibration solution.  The cap is designed to hold
several drops for this purpose.

Cheers,

Glen Duff
-----------------

Quote:

>     Hey there everyone!

>     I recently purchased a PH meter and after I got it they stated that the
> electrode should be stored in a storage solution.  Problem is, I'm getting
> my juice from a vineyard and need to use the PH meter tomorrow.

>     Is there are solution I can prepare or anything I can do to store this
> electrode safely until I can get the proper storage solution?

>     Any help would be greatly appreciated.  Thanks!

>     -Paul

 
 
 

Question about PH Meter Storage Solution

Post by Ren » Tue, 14 Oct 2003 02:43:52


Same stuff as within the electrode for me: 3M KCl (Metrohm probe).
Everything else will make the probe 'leaking' salts, therefore, do
(preferably) not use the pH7 buffer, and certainly not distilled
water.
Watch out for growths as Tom already mentioned, fungi other than
Saccharomyces are everywhere although this high conc of salt generally
will not grow much.

Rene.

Quote:

> Paul,

> The instructions I got with my Hanna pHEP unit is to store it in storage
> solution or pH 7.01 calibration solution.  The cap is designed to hold
> several drops for this purpose.

> Cheers,

> Glen Duff
> -----------------


> >     Hey there everyone!

> >     I recently purchased a PH meter and after I got it they stated that the
> > electrode should be stored in a storage solution.  Problem is, I'm getting
> > my juice from a vineyard and need to use the PH meter tomorrow.

> >     Is there are solution I can prepare or anything I can do to store this
> > electrode safely until I can get the proper storage solution?

> >     Any help would be greatly appreciated.  Thanks!

> >     -Paul

 
 
 

Question about PH Meter Storage Solution

Post by Tom » Tue, 14 Oct 2003 03:09:26



Quote:
> Watch out for growths as Tom already mentioned, fungi other than
> Saccharomyces are everywhere although this high conc of salt generally
> will not grow much.

The reason I recommended heating the KCl solution is that there _was_
something growing in mine.

BTW, to rejuvenate pH probes, someone here recommended contact lens enzyme
cleaner.  Sounds reasonable to me, but I haven't tried it yet.  Worth a try
if the probe is otherwise junk, I'd say.

Tom S

 
 
 

Question about PH Meter Storage Solution

Post by Ren » Tue, 14 Oct 2003 04:30:46


Storage solution is in principle similar to the electrolyt within the
probe, maybe with some preservative added for the problem Tom
mentioned.

For me, that is 3M KCl (or 224 g/l if I remember correctly) for a
Metrohm probe.
All other solutions will leak salts from the probe, but that's
preferable to dry storage!

Rene.

 
 
 

Question about PH Meter Storage Solution

Post by Paul S. Remingt » Wed, 15 Oct 2003 03:10:29


I was wondering about using contact lens saline.  I'm currently using
tap water run through a new PUR water filter.

One other question... I noticed my probe takes about 30 minutes to
provide a stable reading.  My first reading with the probe showed the
must to be about 3.4 after three minutes or so.  I left the probe in
the must for a good half hour and the reading VERY slowly dropped to
3.15 before stabilizing.

Is this normal???  Is the 3.15 reading reliable?  I didn't know it
takes so long to register a reading using a PH meter.

-Paul

Quote:



> > Watch out for growths as Tom already mentioned, fungi other than
> > Saccharomyces are everywhere although this high conc of salt generally
> > will not grow much.

> The reason I recommended heating the KCl solution is that there _was_
> something growing in mine.

> BTW, to rejuvenate pH probes, someone here recommended contact lens enzyme
> cleaner.  Sounds reasonable to me, but I haven't tried it yet.  Worth a try
> if the probe is otherwise junk, I'd say.

> Tom S

 
 
 

Question about PH Meter Storage Solution

Post by Ren » Wed, 15 Oct 2003 04:45:11


Not trying to get my point through :), just not sure google groups did
 go right first time.

Anyway, Tom's rec about probe cleaning is right, often a procedure
with pepsin in 0.1M HCl is mentioned in instruction manuals. Clogging
happens easily in the food industry, not really when working with
wines. Beer musts?

Rene.

Quote:

> Storage solution is in principle similar to the electrolyt within the
> probe, maybe with some preservative added for the problem Tom
> mentioned.

> For me, that is 3M KCl (or 224 g/l if I remember correctly) for a
> Metrohm probe.
> All other solutions will leak salts from the probe, but that's
> preferable to dry storage!

> Rene.

 
 
 

Question about PH Meter Storage Solution

Post by Ken Anderso » Wed, 15 Oct 2003 04:51:29



Quote:
> Not trying to get my point through :), just not sure google groups did
>  go right first time.

> Anyway, Tom's rec about probe cleaning is right, often a procedure
> with pepsin in 0.1M HCl is mentioned in instruction manuals. Clogging
> happens easily in the food industry, not really when working with
> wines. Beer musts?

> Rene.

Actually, you mean beer worts. Wort/must doesn't become beer/wine until the
yeast is pitched. In beermaking, there's no concern about the pH of the
wort, but some guys do check the pH of the mash (the "porridge" step where
water and grains are mixed). IIRC, the right pH helps the conversion of
starch to sugars, but most homebrewers don't worry about it.
Ken A.
 
 
 

Question about PH Meter Storage Solution

Post by Tom » Wed, 15 Oct 2003 11:31:24




Quote:
> I was wondering about using contact lens saline.  I'm currently using
> tap water run through a new PUR water filter.

> One other question... I noticed my probe takes about 30 minutes to
> provide a stable reading.

Your readings are taking so long because you've been incorrectly storing
your pH probe.  Water will leach the KCl from the electrode.  Contact lens
solution is not made for that application either.  Store it in boiled,
saturated KCl solution.

Tom S

 
 
 

Question about PH Meter Storage Solution

Post by Paul S. Remingto » Wed, 15 Oct 2003 23:53:10


    What's interesting is, it took that long before I ever had a chance to
store it!  I first used it  the other day.  I placed it on 4.0 PH buffer
solution and it took a good 15-20 minutes to settle, then I calibrated it.
Did the same for the 7.0 buffer.  Then I did tests with my must during the
course of the evening, rinsing and placing the probe back in the buffer
solution in-between tests.

    All tests took about 20-30 minutes before the meter provided a steady
reading.  Do I have a "sick" electrode?

    -Paul


Quote:



> > I was wondering about using contact lens saline.  I'm currently using
> > tap water run through a new PUR water filter.

> > One other question... I noticed my probe takes about 30 minutes to
> > provide a stable reading.

> Your readings are taking so long because you've been incorrectly storing
> your pH probe.  Water will leach the KCl from the electrode.  Contact lens
> solution is not made for that application either.  Store it in boiled,
> saturated KCl solution.

> Tom S

 
 
 

Question about PH Meter Storage Solution

Post by Paul S. Remingto » Wed, 15 Oct 2003 23:56:37


    I'm using the exact same meter... although I don't see that in my
instructions.  I've been using the pH buffer solution to store it.  Glad to
know that's safe until I can get my hands on KCl solution.  Thanks!

    One of my friends works in a food testing plant and they have gallons of
buffer solutions (clear).  He's gonna draw-off a bunch for me.  I'll have to
ask if they have KCl.

    -Paul


Quote:
> Paul,

> The instructions I got with my Hanna pHEP unit is to store it in storage
> solution or pH 7.01 calibration solution.  The cap is designed to hold
> several drops for this purpose.

> Cheers,

> Glen Duff
> -----------------


> >     Hey there everyone!

> >     I recently purchased a PH meter and after I got it they stated that
the
> > electrode should be stored in a storage solution.  Problem is, I'm
getting
> > my juice from a vineyard and need to use the PH meter tomorrow.

> >     Is there are solution I can prepare or anything I can do to store
this
> > electrode safely until I can get the proper storage solution?

> >     Any help would be greatly appreciated.  Thanks!

> >     -Paul