pH Calibration Solution

[Naja002]

No, I sold my azoo and still have a Rex Rig with 1-2 manifolds, some needle valves, etc. Does the trick for now.....

Is there anything around the house that's good for cleaning a probe? Wouldn't happen to have a link handy, would ya? I'd like to try to clean this one before I toss it......

[spinycheek]

There is a significant difference between 1 point calibrations and 2 point calibrations:

1 Point:
Uses a theoretical pH slope (not the actual slope). It places the point of calibration (4,7,10) on this line so it is correct for that exact point. The further you move from that point, the less accurate your reading will be.

2 Point:
Uses two points and draws a line between them to create a slope. This slope is representative of the probe being used and not of the theoretical perfect pH slope. Every probe performs differently and a 2 point calibration is the only way to correct for this. It means that even if you move from the points of calibration, you are still accurate.

On a side note. If you use a 10 buffer for calibration, the shelf life is very short ~ 1 month after it is opened. It absorbs CO2 from the air and its actual pH drops. The accuracy of the probe is only as good as the calibration solutions.

[Left C]

Originally Posted by Naja002

No, I sold my azoo and still have a Rex Rig with 1-2 manifolds, some needle valves, etc. Does the trick for now.....

Is there anything around the house that's good for cleaning a probe? Wouldn't happen to have a link handy, would ya? I'd like to try to clean this one before I toss it......

I believe that you can soak it in a warm 4 pH buffer solution to clean it, but let me check around first.

I'll check around this afternoon. I don't have time right now. I'm going to have lunch with this 80 years young lady today. She's a blast to talk too.

I remember seeing some articles a while back and I'll check out my biotechnology books too.

[Left C]

Originally Posted by Naja002

... Is there anything around the house that's good for cleaning a probe? Wouldn't happen to have a link handy, would ya? I'd like to try to clean this one before I toss it......

Originally Posted by Left C

I believe that you can soak it in a warm 4 pH buffer solution to clean it, but let me check around first.

I'll check around this afternoon. I don't have time right now. I'm going to have lunch with this 80 years young lady today. She's a blast to talk too.

I remember seeing some articles a while back and I'll check out my biotechnology books too.

This comes from the book: Basic Laboratory Methods for Biotechnology: Textbook and Laboratory Reference by Seidman and Moore. Pages 357 and 358

Cleaning the Junction of a Reference Electrode
These methods are suitable for combination electrodes or individual reference electrodes. The first methods are least drastic and should be tried first. Continue to the next step only if the previous one has failed.

- For gel-filled and calomel references, soak the electrode tip in warm water (about 60°C or 140°F) for 5 – 10 minutes. Be careful not to heat the water much above 60°C.
- Dissolve crystals from the end of the electrode by soaking in a solution of 10% KCl and 90% distilled water for between 20 minutes and 3 hours. Warm the solution to about 50°C or 122°F. Immerse the electrode about 2” into the solution.
- Use a commercially available junction cleaner.
- Remove any proteins that coat the outside of electrodes or penetrate into the junction. Recommendations for removing protein deposits include rinsing in enzyme detergent like Tergazyme (from Alconox) or using pepsin/HCl cleaners like Oakton Electrode Cleaner.

Cleaning the Measuring Electrode Bulb
Use a soft tooth brush, Q-tip or tissue to clean the bulb. Gently wipe or pat the bulb; do not rub.
- Remove dirt with warm soapy water. A mild dish washing detergent without hand lotion can be used.
- Remove protein contaminants by washing in warm water with an enzyme detergent like Tergazyme or Oakton’s Electrode Cleaner followed by rinsing in water.
- Remove inorganic deposits by washing with EDTA, ammonia or 0.1 N HCl. Rinse the bulb with water and soak it in dilute KCl.
- Remove grease and oil with methanol or acetone. Rinse the bulb with water and soak it in dilute KCl.
- To remove fingerprints, wipe the bulb gently with a 50/50 mixture of acetone and isopropyl alcohol. Soak the electrode in a commercial soaking solution or pH 4 buffer for 1 hour.

Rejuvenating a Measuring Electrode Bulb
Note that solutions used for soaking and conditioning a pH measuring electrode are usually slightly acidic. This is because H+ ions from the soaking solutions replace contaminates in the glass of the bulb.

Some manufactures recommend the following steps when the linearity of the system is poor or the system response is sluggish. The first methods are least drastic and should be tried first. Continue to the next step only if the previous one has failed.
- Soak the bulb in pH 4 calibration buffer overnight.
- Soak the bulb in 1 M HCl for 30 minutes.
- Immerse the bulb in 0.1 M HCl for about 15 seconds, rinse with water, then immerse in 0.1 M KOH (or 0.1 M NaOH) for 15 seconds. Repeat several times and rinse. Soak the electrode in pH 4 buffer overnight.


Here are some additional sources of information:

http://www.phadjustment.com/pH_Probe_Service.htm

http://home.comcast.net/~mzapx1/FAQ/pHProbes.pdf

http://home.comcast.net/~mzapx1/FAQ/pHProbes.pdf

[loganutah]

Does this work the same way with a Pen style PH tester?
Mine said to calibrate at 2 solutions.

I live in a small town with only petsmart. Where do I get the 2 solutions to calibrate this thing? Grocery store?

Also how long can you go between calibration?

[Naja002]

Thanx, LeftC. Wkends are my busy time, but now I should be able to sift through it in the next few days...... Not really familiar with the chemical names--KCI=NoSalt, Got it. Any "household" versions of the other stuff? HCl, KOH, etc......

[Left C]

Originally Posted by loganutah

Does this work the same way with a Pen style PH tester?

Yes

Originally Posted by loganutah

Mine said to calibrate at 2 solutions.

For a planed tank use, get the 4.00 and 7.00 or 4.01 and 7.01 buffer solutions

Originally Posted by loganutah

I live in a small town with only petsmart. Where do I get the 2 solutions to calibrate this thing? Grocery store?

The manufacturer of the pH tester usually has the buffer solutions required. You can contact them.

You aren't going to find them at Pet Smart or a grocery store.

American Marine (Pinpoint), Milwaukee Testers, Hanna, Oakton, etc. are some of the companies that provide the buffer solutions.

Here's some places that carry them:
Big Al's - http://www.bigalsonline.com/edealinv...query=pinpoint

DrsFosterSmith.com - http://www.drsfostersmith.com/produc...fm?pcatid=4512

ThatPetPlace.com - http://www.thatpetplace.com/pet/prod...olutions&sp.pr[0]=0.0&sp.pr[1]=0.0&sp.offset=0&_page=1&sp.wkey=245&sp.skey=&sp.m fn=&sp.mpn=&e0=&e1=&e2=&e3=&e4=

AquaBuys.com - http://www.aquabuys.com/page/aqb/CTGY/j2

MarineDepot.com - http://www.marinedepot.com/ps_search...tions&parsed=1

Originally Posted by loganutah

Also how long can you go between calibration?

You should calibrate it before use.

You don't want the tip to dry out. You should keep the probe wet by keeping it in a pH/ORP storage solution: http://www.thatpetplace.com/pet/prod/212777/product.web

[Left C]

Originally Posted by Naja002

Thanx, LeftC. Wkends are my busy time, but now I should be able to sift through it in the next few days...... Not really familiar with the chemical names--KCI=NoSalt, Got it. Any "household" versions of the other stuff? HCl, KOH, etc......

Did you get your Omega PHE-4202 probe from Omega?

KCl is Potassium Chloride or NoSalt. A pH probe solution is usually 4 M KCl. Here's some for sale: http://www.thatpetplace.com/pet/prod/212777/product.web

For HCl, you can use Muriatic Acid with is usually 33% to 40% HCl to make the 0.1 M and 0.1 N solutions. In this case the 0.1 M and 0.1 N solutions are the same. HCl is 36.458 g/mol.

Warning: KOH and NaOH are very strong alkalies. Handle with the proper equipment.

KOH is Potassium Hydroxide or lye. Sometimes you can still find Red Devil Lye which is KOH. I believe that Red Devil no longer sells that particular product. Here's a sack of it for $15 including shipping. (You can make a bunch of soap with what you have left over. ) http://cgi.ebay.com/Red-Devil-Lye-ba...QQcmdZViewItem

NaOH is Sodium Hydroxide or caustic soda. Here's some places that sell it: http://www.google.com/products?hl=en...-8&sa=N&tab=wf

Tergazyme is expensive. I got my Oakton Electrode Cleaner from AquaticEco.com.

Use the non-scented ammonia.

Does this cover all of the chemicals for you?

[sonaps]

Originally Posted by Naja002

Is there anything around the house that's good for cleaning a probe?

Here's what Milwaukee recommends:

Q. My pH meter has a little mold or dirt on the white strip and bulb will that affect the performance?

A. Yes, you can clean the probe in Isopropyl Alcohol ( rubbing alcohol ): Put the probe in full strength for 10 min. stirring
gently then rinse well in tap water and let sit in Bottle Drinking Water ( RO water ) for 2 hours and then recalibrate.

I got this information from Milwaukee's website: http://milwaukeetesters.com/english/...ph-ec_info.pdf Scroll down to pages 3 and 4 of the PDF for pH General Information.

Edit: Sorry, the link didn't past right the first time. It's fixed now.

[Naja002]

Originally Posted by Left C

Did you get your Omega PHE-4202 probe from Omega?

Yep.

Originally Posted by Left C

KCl is Potassium Chloride or NoSalt. A pH probe solution is usually 4 M KCl. Here's some for sale: http://www.thatpetplace.com/pet/prod/212777/product.web

For HCl, you can use Muriatic Acid with is usually 33% to 40% HCl to make the 0.1 M and 0.1 N solutions. In this case the 0.1 M and 0.1 N solutions are the same. HCl is 36.458 g/mol.

Warning: KOH and NaOH are very strong alkalies. Handle with the proper equipment.

KOH is Potassium Hydroxide or lye. Sometimes you can still find Red Devil Lye which is KOH. I believe that Red Devil no longer sells that particular product. Here's a sack of it for $15 including shipping. (You can make a bunch of soap with what you have left over. ) http://cgi.ebay.com/Red-Devil-Lye-ba...QQcmdZViewItem

NaOH is Sodium Hydroxide or caustic soda. Here's some places that sell it: http://www.google.com/products?hl=en...-8&sa=N&tab=wf

Tergazyme is expensive. I got my Oakton Electrode Cleaner from AquaticEco.com.

Thank You! Really not interested in buying a bunch of stuff--unless its cheap and easy to come by......

Originally Posted by Left C

Use the non-scented ammonia.

I missed something.....where does the ammonia come into play? I have some ready to go.....

Originally Posted by Left C

Does this cover all of the chemicals for you?

I sure hope so.......!

Originally Posted by sonaps

Here's what Milwaukee recommends:

Q. My pH meter has a little mold or dirt on the white strip and bulb will that affect the performance?

A. Yes, you can clean the probe in Isopropyl Alcohol ( rubbing alcohol ): Put the probe in full strength for 10 min. stirring
gently then rinse well in tap water and let sit in Bottle Drinking Water ( RO water ) for 2 hours and then recalibrate.

I got this information from Milwaukee's website: http://milwaukeetesters.com/english/...ph-ec_info.pdf Scroll down to pages 3 and 4 of the PDF for pH General Information.

Thank You, sonaps--going to try this one first......

[Left C]

Originally Posted by sonaps

Here's what Milwaukee recommends:

Q. My pH meter has a little mold or dirt on the white strip and bulb will that affect the performance?

A. Yes, you can clean the probe in Isopropyl Alcohol ( rubbing alcohol ): Put the probe in full strength for 10 min. stirring
gently then rinse well in tap water and let sit in Bottle Drinking Water ( RO water ) for 2 hours and then recalibrate.

I got this information from Milwaukee's website: http://milwaukeetesters.com/english/...ph-ec_info.pdf Scroll down to pages 3 and 4 of the PDF for pH General Information.

Edit: Sorry, the link didn't past right the first time. It's fixed now.

Thanks for the Milwaukee link, sonaps.

This is another good tip from that link:
Q. How can I test the life left in my probe?

A. A simple test can be performed using Windex glass cleaner with ammonia and any type of soft drink The procedure is as follows: Turn your meter or tester on and place the probe in a soft drink which is acidic and the reading will be from 2.7 to 3.9 then go to the Windex with ammonia which is alkaline. Your display should move very quickly up the scale to 10.5 – 11.8 If the probe slowly moves up the scale then it is time to consider replacing it.

[Left C]

Originally Posted by Naja002

Yep.

Thanks.

Originally Posted by Naja002

Thank You! Really not interested in buying a bunch of stuff--unless its cheap and easy to come by......

Some of those chemicals are for use in a lab or facility that has the proper equipment, procedures and storage abilities to handle them.

NaOH is something that you don't want in your house. You can add some of it to water and it does it's job. If you happen to get some water on a open container of it, it could catch on fire. It's wicked stuff!

Originally Posted by Naja002

I missed something.....where does the ammonia come into play? I have some ready to go.....

It came from this section:
Cleaning the Measuring Electrode Bulb
Use a soft tooth brush, Q-tip or tissue to clean the bulb. Gently wipe or pat the bulb; do not rub.
- Remove dirt with warm soapy water. A mild dish washing detergent without hand lotion can be used.
- Remove protein contaminants by washing in warm water with an enzyme detergent like Tergazyme or Oakton’s Electrode Cleaner followed by rinsing in water.
- Remove inorganic deposits by washing with EDTA, ammonia or 0.1 N HCl. Rinse the bulb with water and soak it in dilute KCl.
- Remove grease and oil with methanol or acetone. Rinse the bulb with water and soak it in dilute KCl.
- To remove fingerprints, wipe the bulb gently with a 50/50 mixture of acetone and isopropyl alcohol. Soak the electrode in a commercial soaking solution or pH 4 buffer for 1 hour.