How to test for moisture in Jet Fuel Oil using a Karl Fischer titrator

By Hank Levi on Mon, Sep 21, 2015 @ 03:15 PM


From start to finish watch this short video to see how a sample of Jet Fuel Oil is tested for water content using a karl Fischer Titrator. For this training video we use:

  1. The Aquapal III coulometric Karl Fischer Titrator (setup as a dual reagent configuration)
  2. Reagents; Anolyte is coulomat AG and the catholyte is coulomat CG
  3. A 4-place analytical balance SA-80
  4. And a disposable syringe and disposable needle

In this video you will see the steps for running a test successfully including how to:

  1. Extract your sample into the syringe
  2. How to weigh your sample and tare the balance
  3. How to inject a sample properly
  4. How to input the sample weight and obtain a final result

 

We hope you found the video helpful and informative!  If you think a colleague could benefit from this please share it with them!  Click on the twitter button to automatically share this video!

Tweet: How to test for moisture in Jet Fuel Oil using a Karl Fischer Titrator http://bit.ly/1NJ8If4"How to test for moisture in Jet Fuel Oil using a Karl Fischer titrator"


 

Thanks for Watching!
Continue Reading

Review of KEM's new 2015 titration line

By Hank Levi on Tue, Jun 09, 2015 @ 04:11 PM


Review of KEM's new 2015 titration line 

AT-710S_M Automatic Titrator

I don't know about you but I have to admit that I enjoy learning about new technology.  Whether it's smart phones, cars, or kitchen appliances I think it's fun to find out about how a product has changed (hopefully for the better). For the most part a lot of consumer products see a change or upgrade about once every year. This is not really the case for titrators where maybe it's only every 6 to 8 years before we see a new generation unveiled.  I guess that's why I thought maybe it would be a good idea to take a look at this new 710 series that came out in February 2015.  I haven't actually ever written a "review" before so I decided to start by comparing what I know about some of the current titrator models and identify the things that pop out with the new titration line.   Here are my observations and comments.


Link to pictures and information about the 710 series titrators: http://info.scientificgear.com/kem-titrator-710-series-information


 

1. There are now three model levels; entry, mid-level, and flagship within each category (volumetric Karl Fischer, coulometric Karl Fischer, and automatic potentiometric titrator) 

My comment: I like the scale of the models as it can be helpful for those with varied budgets and needs.  I like the concept that you can start with getting only the basic model at first and then later bring in the flagship model and tie them all together into one system.  It will be interesting to see how people approach these options and whether the ability to expand a system is desirable or not.
710_series_titrator_with_2_burettes

2. All of the automatic titrators now can accommodate two burette drives

My comment: The automatic titrators come with one burette drive but being able to add a second burette drive allows an operator to run two separate titrations (titrants) without having to use an automatic piston burette.  Historically most titrator manufacturers offered only a single burette drive but it seems like this is changing.  It's kind of a big deal for those who run two different titrations and don't want to purchase an automatic piston burette.  I like this new capability.

3.  A new burette design for the automatic titrators and volumetric Karl Fischer titrators.

SmartBuretteUnit

My comment: The burettes appear they will be easier to store and swap as the titrant bottle, burette and nozzles all go together as one smaller unit.   The burettes are now "smart" burettes and can store all of the reagent information within the head of the burette.  I like this.

4.  More Input/Output options for operators to move  and store data.  I/O options include LAN connectivity/URL, USB hubs, USB thumb drive ports, .CSV file format, .PDF file format, barcode readers, foot switches, and keyboards.710seriesUSB

My comment:  More technology is built into these units. I think it was overdue so I am glad to see it finally arrive.

AT710_w_propeller_or_magnetic_stirrer

5.  Automatic Titrators now come with a propeller stirrer by default but can swap for a magnetic stirrer instead.

My comment: I like the option to do both but I think maybe the magnetic stirrer should have been the default and the propeller as the option.

 

6.  A new Wireless/ Wired 8.4 inch color touch panel controller (MCU).

MCU_screen_view_with_multiple_units

My comment: This only comes with the mid-range and the flagship models.  The controller can sit next to the titrator or be carried around like a clipboard.  Operators can control the titrator through protective glass if necessary.  I'm not sure how many people will elect to use the wireless vs. the wired connection but it's nice to have the added capability.  Nice.


7.  Multi-titrator integration.  The wireless/wired MCU can control up to 4 different titrators simultaneously (any combination of Karl Fischer or automatic titrator) 

MCU_controller for 710 series titrators

My comment: This feature is reserved for the flagship model.  I can see this being useful for those needing to run both moisture and acid for example.  Unfortunately the mid-level model MCU cannot be upgraded to the MCU flagship model so if you think you might expand later don't go with the S model.  Your better off getting the basic "B" model and then later tying them all together from the flagship model.

 710seriesmulticontrol

8.  Free method making software.

My comment:  All of the titrators now come with a CD that allows you to create methods on your PC and then transfer methods to the titrator.  You can also pull methods off of the titrator and edit it in the PC.  The software also comes with various popular methods pre-loaded to help get methods setup quicker.  I'm not so sure how robust this software is but free is nice.

CDstoredmethods




CONCLUSION:

Well I hope this was helpful in finding out quickly what the updates are for the new 710 series.  At this point since it's so new we will have to wait to evaluate how customers feel about their user experience and get their feedback on what they liked most and what they liked least.  If you have any questions or comments you can email me at info@scientificgear.com



 

Continue Reading

How to use Karl Fischer Grease

By Hank Levi on Sun, Jan 19, 2014 @ 01:57 PM

Karl Fischer GreaseCertain types of Karl Fischer vessels require the use of Karl Fischer grease. Vessels with smooth port openings need a thin layer of the grease applied to plugs, electrodes, dessicant tubes, bubbler tubes and injection port plugs to help form a snug fit.  Decreasing or limiting "ambient moisture" from getting into the vessel - otherwise known as "drift" - is the key benefit of using Karl Fischer grease.  Another benefit of Karl Fischer grease is that it also helps prevent chipping of glass on glass fittings.  Watch this short video to see how Karl Fischer Grease should be applied.


If you find this information helpful please consider subscribing to our blog.  Once you subscribe you will get notified when we post a new article.

Continue Reading

How do Ketones & Aldehydes affect Karl Fischer moisture testing?

By Hank Levi on Mon, Sep 23, 2013 @ 04:32 PM

Measuring moisture using a karl Fischer Titrator is a common and popular choice among operators.  Karl Fischer titration provides excellent accuracy at the part-per-million (PPM) level and is widely accepted and trusted as a reliable method for measuring moisture.  Ketones and Aldehydes however are two organic compounds that can cause problems and lead to errors with measured results if they are present in a sample during testing.  The presence of these organic compounds can create an unwanted side-effect inside the titration vessel.

 ketoneWhat are the side-effects?   aldehyde

The effects are side-reactions that can either falsley increase your moisture results or falsley reduce your moisture results.  Depending on whether your dealing with ketones or aldehydes or both you will want to know how to deal with them.  

How do you solve the problem?

Once you have identified the problem you need to take stock in your equipment and the chemical reagents you are using.  The equipment setup and reagent choices you make can help you to suppress these side reactions and obtain accurate results.

Watch this short 3 minute video to learn about the preferred equipment setup and your chemical reagent choices.

 

 

                           Still need help? Click here.

 

Continue Reading

Karl Fischer Over Titration and 7 things you should know about it

By Hank Levi on Wed, May 02, 2012 @ 06:30 PM

We have all seen it.  We’re running a test to see how much moisture is in our sample when inexplicably the liquid inside the Karl Fischer vessel starts to turn from a normal light-yellow color to a dark burnt-red looking color.  Sometimes the titrator screen will inform us of the problem with a digital readout stating the dreaded

OVER-TITRATION!” 

kfbeforestart resized 600describe the imagedescribe the imagedescribe the image

 

Sometimes the digital readout says nothing at all.  In either case the operator knows something has gone wrong because the Karl Fischer Titrator is no longer giving moisture results.  A panic to figure out the problem and get testing underway again becomes the immediate priority. 

But where do you start?  

As it turns out “over-titration” is probably one of the top 2 or 3 complaints or issues we hear about from operators.    So what is causing this problem to occur?  How can we determine the source of this problem, fix it, and more importantly how can we avoid it?

 
This is a critical question for operators and managers working in a production or QC environment who are concerned with keeping their Karl Fischer Titrator 100% “in-service”, day-in and day-out.   Having the ability to identify the problem correctly so appropriate measures can be taken quickly is very important.

 
So how do we approach the problem of “over-titration”?   By knowing the facts.  Having a clear understanding of the process can help operators correct the problem faster when time is of the essence.  

Important facts you should know about over-titration:  
  1. Over-titration is a state where there is more iodine present in the vessel than water (general definition).
  2. When over-titration occurs the vessel will become very dark as a result of the abundance of iodine present inside the vessel.
  3. The reagent inside the vessel should normally have a light-yellow color absent a very dark sample such as oil.
  4. The Karl Fischer Titrator always attempts to maintain an equilibrium where only enough iodine is introduced to counter and neutralize the water present inside the vessel.
  5. During a single titration test there should only be enough iodine introduced to counter and neutralize the amount of water present inside the titration vessel during that test – no more, no less.
  6. Any incident that interferes with the final amount of iodine introduced during the titration test can lead to dis-equilibrium and result in more iodine being introduced than necessary.
    Important facts you should know about Karl Fischer Titrator Glassware:  
  1. The Karl Fischer Vessel and Glassware is composed of the following
    1. Vessel (coulometric and volumetric)
    2. Generator Electrode (coulometric only) - The Generator Electrode is a precision electrode designed to deliver an electrical current inside the vessel to the reagent – causing the reagent to produce iodine
    3. Titration nozzle (volumetric only) - The titration nozzle delivers precise amounts of iodine (composite or titrant) via a burette driven mechanism using a piston
    4. Detector Electrode (coulometric and volumetric) - The detector electrode has a sole purpose and probably the most important role in continuously monitoring and determining the conductivity levels within the titration vessel.
  So what are the causes that can lead to over-titration? 

✓ A damaged Detector Electrode

✓ A "Tricked" or "Fooled" Detector Electrode (no joke)

 

Since coulometric and volumetric Karl Fischer Titrators handle the delivery of iodine differently it’s worth describing the two methods separately.  

A Word About Coulometric Karl Fischer Titration:

In a coulometric system the reagent is a complete system where it is designed to release iodine when the generator electrode delivers an electrical current to it.  So what causes the generator electrode to deliver too much current causing the over production of iodine?  Another way to say it is, “who or what” is telling the generator electrode to continue to generate a current when it’s not needed?  

   
The detector electrode!  So why would the detector electrode do this?   describe the image
Without getting into too much of the electronics the detector electrode is designed to “detect” conductivity in the vessel.  Depending on the amount of conductivity detected the detector electrode will send a message to the titrator telling it to continue producing a current - enough to release the appropriate amount of iodine to counter and neutralize the water present in the vessel.  As long as this process is working during a titration an eventual endpoint will be found and a result will be produced.  


So it’s really a problem of misinformation. If the Karl Fischer Titrator is not getting the right information from the detector electrode then over-titration is possible. 

The problems we see that can effect the proper functioning of the detector electrode include:  
  1. The electrode cable.  If the cable becomes cracked or breaks it can cause a situation where the message to the titrator is to continue producing a current – continually.  In this case the vessel will become very dark and in most cases the titrator will not even know it is in an over-titration state.  The generator electrode will simply continue to produce a current, turning the vessel very dark.  There will be no other warning or notice from the titrator for the operator to see.
  2. Cracked electrode.  Sometimes mishandling or even a stirrer bar bouncing around inside the vessel can cause a tiny crack near the bottom of the detector electrode that cannot be seen with the naked eye.  These cracks can allow small amounts of reagent inside the electrode enough where errors in detection will begin to occur.  What ensues is an unstable drift that jumps around giving the titrator a misreading. The jumping around and unstable drift may be picked up by the titrator and an error stating “OVER TITRATION” may be seen on the screen of the titrator.
  3. Cable connectors.  Sometimes the connectors on the titrator itself can become dirty, wet and corroded.  Also, some electrodes use multi-plug designs that can also become dirty, wet and corroded.   These connectors if not clean and dry can lead to a similar misreading similar to a cracked electrode where the drift begins to jump around and become unstable.  The titrator may also state that there is “OVER TITRATION” when this occurs.
A "Tricked" or "Fooled" Detector Electrode you say?describe the image

If it’s determined that the problem is not the detector electrode then we need to look at the stirring action inside the vessel.  If the iodine being released is not mixing well because the stirrer is off or set too low, then the detector electrode will not realize there is iodine already released inside the vessel.  This will cause the detector electrode to continue telling the titrator to produce more current via the generator electrode up to the point where the detector electrode senses a reduction in the conductivity level inside the vessel.  Conductivity only reduces as the iodine interacts with the water.  So it is important for the detector electrode to sense the true and most accurate “mix or state” of iodine and water during the titration process.  If it does not know the true state of the mix it will be fooled into telling the titrator to keep going – causing OVER TITRATION.        

A Word About Volumetric Karl Fischer Titration:

   
describe the imageIn a volumetric system the reagent setup is different where a composite or titrant is introduced via a burette piston through a titration nozzle.  The amount of composite or titrant delivered is based upon the commands of the titrator.  The command from the titrator to the burette and piston that push out the “iodine” through the titration nozzle is, yes, given by the detector electrode.  For the purposes of this discussion the difference between the coulometric and volumetric setup is that the delivery of iodine is different.   But the same problem can occur where the iodine does not mix well and therefore trick the detector electrode in to thinking there is not enough iodine present inside the vessel to counter and neutralize the water.  Since both coulometric and volumetric Karl Fischer Titrators use detector electrodes the problems mentioned earlier about the detector electrode will hold true with volumetric titrators also.  

 

 

  7 Thoughts (DOs and DON'Ts) on Problem Solving and Prevention:  

1.  Don’t abuse the detector electrode!  Be very careful with the detector electrode and do not handle it unnecessarily.  Small bumps (clanks) here and there can lead to a crack.   Do you really need to remove the detector thinking dragonelectrode from the vessel all the time?
2.  Don’t turn up the titrator’s stirrer speed to high.  This will only cause the stirrer bar to bounce around uncontrollably and possibly hit and damage the detector electrode (crack).
3.  Do inspect all connections and connectors on the detector electrode cable and Karl Fischer Titrator to ensure they are dry and clean.
4.  Do be careful with the detector electrode cable.  Try not to bend it unnecessarily.
5.  Do make sure there is enough stirring action inside the vessel to mix the iodine around effectively.  A small vortex should be visible.  But not too fast to cause the stir bar to bounce around.
6.  Do introduce some moisture - Sometimes when you are in an over-titration situation and the vessel is already very dark you can introduce a little moisture to bring the vessel back to equilibrium.  This sometimes works and immediately the vessel turns from a dark burnt-red color to a light-yellow.
7.  Do have a spare detector electrode on hand.  This little electrode seems to get over looked but plays a huge role inside the Karl Fischer Titrator vessel.

Created on 05/02/12 at 18:10:44

Continue Reading

Karl Fischer Titrator not finding all of the moisture you expected?

By Mark Levi on Sun, Jan 08, 2012 @ 03:01 PM

Aquapal IIIIf your operating a dual-reagent Karl Fisher Titrator and your getting lower than expected moisture results you may want to check a few things.  First, make sure your analytical balance or specific gravity (if you use it) calculation is not the problem. Next, focus your attention on the reagents.

Reagents can cause problems if they are not being replaced often enough.

With a dual-reagent setup the operator places anolyte into the main vessel (75mL to 150mL of anolyte solution depending on the vessel size) and catholyte into the generator electrode (5mL of catholyte solution).

Now for some reason, most operators focus their attention primarily on the anolyte reagent and take great care in monitoring the condition and level of the anolyte. Unfortunately their is a tendency to forget about the catholyte. I say unfortunately because it is this oversight that can cause the problem.

Before I tell you the reason for the problem it’s helpful to know some useful information about the reagents ability to measure moisture. A typical vessel can hold 100mL of anolyte. 100mL of anolyte (Coulomat A, Coulomat AG, Coulomat AG-H) can measure 1,000,000 micro grams of water. Yes, 1 million micrograms of water!. Conversely, the pre-measured 5mL ampules of catholyte solution (Coulomat CG) that goes into the generator electrode has the ability to only measure 300,000 micro grams of water per 5mL charge. Do you see it?  Do you see the connection?

There is a 3 to 1 relationship of the cathoyte to anolyte!

Yes, you should be replacing the catholyte 3 times per 1 charge of the vessel. Or put another way, change the catholyte 3 times as often as you change the anolyte.


Now, back to the problem and the answer. If your not replacing the catholyte often enough, the catholyte will actually begin to convert and form a salt by-product. This “salt by-product” can then form and become deposited down around the frit at the bottom of the generator electrode (AKA inner buret) and clog the receptors. When this happens the generator electrode does not work as effectively and can contribute to low recovery on expected moisture levels.

What's the fix?

  1. Make sure to change the catholyte more often as required.
  2. Soak your generator electrode in methanol or even a light acid over night to clean out some of those salty deposits. That should help.

In these last two pictures we show a Karl Fischer Vessel with a Single-Reagent Generator Electrode inside. Notice how there in no frit at the bottom? -All you see is the platinum screen. In the other picture you can see the bottom of a Dual-Reagent Generator Electrode.  See the white wafer?  This is where the deposit build-up occurs.  Just thought it would be helpful to show both and the differences.

Single GEDual GE

(Note: Coulomat AK anolyte and Coulomat CG-K catholyte are used in combination for samples with Keytones and have a 1 to 1 relationship and can measure 100,000 micrograms of water. Also, the popular Coulomat Oil anolyte has a smaller amount of moisture measuring capability as compared with the other mentioned anolytes above and has a capacity to measure 300,000 micrograms of moisture. eg. If your using Coulomat oil anolyte and Coulomat CG both have the capacity to measure 300,000 micro grams of water and have a 1 to 1 relationship.)

Hope this helps.

Continue Reading

Karl Fischer Titration and Water Standard Presentation

By Hank Levi on Tue, Jun 28, 2011 @ 10:43 AM

Kf waterstandard presentation resized 600In this presentation we discuss the basic Karl Fischer Water Standards and talk about some of their uses for both Coulometric and Volumetric Karl Fischer Titration.  We also describe some of the related problems that can be identified and overcome by using Karl Fischer Water Standards.

  • Karl Fischer Water Standards
  • Why we use them
  • Coulometric Karl Fischer
  • Volumetric Karl Fischer
 

Created on 06/28/11 at 10:48:28
Continue Reading

Karl Fisher Titration and the 20 Most Critical Questions

By Hank Levi on Sun, Jun 12, 2011 @ 12:27 PM

questionsAs a service provider of Karl Fisher testing apparatus, we see different moisture testing issues that many operators, managers, and even companies face. We have come to realize that helping operators become more knowledgeable about "the little things" can help boost confidence, improve performance and efficiency, and ensure accurate testing. 

Are you new to Karl Fisher Titration and just beginning to learn about moisture testing or has it just been a while since you had to pull the Karl Fisher Titrator out to run some tests?  Regardless of your reason we know how important it is to get up to speed quickly so you can be running tests and providing moisture test results to those who need them.

To help with this we have compiled a list of the 20 most critical questions to help operators navigate through the learning curve and gain a better understanding of Karl Fisher Titration.

Some examples of issues you will discover include:

1.  "Our Karl Fisher says 'OVER TITRATION' and the reagent is turning really dark. Why?”

2.  “Why won’t the instrument go into “Ready mode”?”

3.  “Results seem "all over the place", what should I do?”

4.  "We use a solids evaporator and we are getting ZERO moisture results. Why?"

5.  "How many tests can I run and when should I change out my reagents?"

 

Avoid unnecessary surprises by getting a copy of the complete list of questions and learn what the issues are and why they are important.

Created on 06/11/11 at 08:00:22

Continue Reading

Karl Fisher Titration and drift

By Hank Levi on Fri, Jun 03, 2011 @ 12:36 PM

karl fisher driftSimply put, drift is background moisture that the Karl Fisher titrator is detecting.  What is background moisture?  Well, it is moisture that the Karl Fisher titrator (specifically the detector electrode) is detecting inside the vessel -that’s not coming from your sample.  Drift or "background moisture" can be the result of having the titration vessel sitting idle for some time where moisture has slowly infiltrated and accumulated inside the vessel, or it may be the result of a leak that is allowing a small amount of moisture to enter the vessel continually.  Although we might like to think that the Karl Fisher titrator vessel is air-tight/moisture-tight, it is not.  Depending on how well the vessel is sealed there may be a little or there may be a lot of background moisture interference.  All Karl Fisher titrators deal with the drift issue.  Unfortunately drift cannot be completely eliminated but the good news is that it can be reduced, measured, isolated, and discarded from your test results.
Before a single test is run on a Karl Fisher titrator it must go into a “ready” mode.   But before the titrator can go into a “ready” mode it most likely will go through a “pre-titration” mode.  During the “pre-titration” mode excess drift (moisture) is detected and removed by the reagent inside the vessel.  A “ready” mode ideally will occur when the drift being measured is low and steady/stable – usually below .1 micro grams per second.  Once the drift becomes low and stable the Karl Fisher Titrator records the drift level and goes into a “ready” mode and will allow the operator to introduce a sample into the vessel.  Upon completion of the test the Karl Fisher titrator adds up all of the moisture detected over the duration of the test and subtracts out the known drift level that was also measured during the test.  This process of knowing what the drift was before the test allows the Karl Fisher Titrator to then determine and backout the drift -leaving only the moisture detected from the sample as your result.

 

Created on 06/03/11 at 12:38:02

Continue Reading

Karl Fisher Titration Advantages for measuring moisture

By Hank Levi on Thu, Jun 02, 2011 @ 11:12 AM

Karl FisherThere are multiple methods of moisture determination, including loss on drying, Karl Fischer titration, piezoelectric sorption, spectroscopy, and chilled mirrors among others. However, it is advantageous to use Karl Fischer (KF) titration in moisture analysis for the following reasons:

  • It is highly accurate and precise (Part Per Million Accuracy).
  • KF is specific to water determination. This specification is different from the other popular moisture analysis method, loss on drying (LOD), because LOD can detect the loss of any volatile substance. However, this specification is advantageous because it allows KF titration to work independent from volatile substances present in the sample
  • The process does not require large samples, which is typically truer with Loss on Drying where more sample is required to achieve higher accuracy and repeatability - which introduces another entirely different problem.
  • It does not require much time to perform an analysis since the samples are easy to prepare and the analysis itself is short in duration.
  • The method has a nearly unlimited measurement range (from 1ppm to 100%).
  • Karl Fischer titration can determine the moisture content of a sample in any state, whether it is a solid, liquid, or gas.

We hope the above advantages show some of the benefits that Karl Fischer titrators can provide.  Even today with technological advancements Karl Fisher Titration remains very popular not only because of the advantages we mention, but also because it is widely accepted as a standard for moisture detection and measurement.

Continue Reading