Lab Queries: What to Do When Things Go Wrong

I’m sure you’ll all be happy to know that this week on the blog we are leaving calibration curves and math behind us!

Don’t worry, if you still have questions about instrument calibrations, or a new issue arises in your lab, I’m always here to help you address those.  In talking to some of you at FELC a few weeks ago, the issue of troubleshooting came up a few times.  I know this can be a hard topic and really digging into a broken instrument can be an intimidating idea for some people.  But I’m going to let you in on a secret….it’s maybe one of my favorite activities to do!

I’m weird….I know…..I’ve accepted it and moved on. 😊

What to Do When Things Go Wrong

We’ve all had that moment….we started samples on an instrument, left for the night expecting to come back in the morning to a nice, completed data set, and return to find that our instrument malfunctioned!  Now results are behind schedule and you have the added issue of an instrument that just refuses to cooperate.

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Troubleshooting can be a frustrating and tricky activity to complete, especially because instruments never break at convenient times.  If I had a dollar for every time an instrument broke when I had rush samples to do, I wouldn’t have to work anymore!  But, because instruments will always continue to break, and I need to keep my job, I thought I’d fill you in on some of my favorite troubleshooting tips.

  • Follow the Path

A good way to make sure you don’t overlook any parts of your instrument is to start at one end of the instrument and follow the sample path through to the other end.  It’s easy to jump from place to place first, maybe checking your sample loop before jumping up to check your eluent filters.  Odds are that you’ll over look something, and your issue will be in the place you over look.  Following the path helps ensure that you give every section of you instrument it’s due investigation.

  • The Tubing Checker

One of my new favorite troubleshooting tools is a spare autosampler syringe!  When I need to troubleshoot one of my instruments with a large amount of tubing, I’ve found that using the syringe to carefully inject DI water into each section of tubing is a quick and easy way to look for the source of the problem.  Maybe a section of tubing is plugged, maybe it’s cracked, maybe there’s a dust bunny lodged in the end (true life this has happened to my IC!!)  It’s so hard to tell sometimes by just eyeballing the sections, but this technique has yet to fail me!

  • Look Beyond the Science

Sometimes the source of an instrument issue isn’t related to the “science-y” components we would typically focus on.  Sometimes exhaust fans wear out or autosampler screws fall out or sheer off.  Don’t be afraid to look into the more mechanical parts of your instruments.  Think of them as support systems.  If your autosampler syringe housing is loose and wobbly because a screw is loose, maybe the syringe isn’t being held firm enough to puncture the vials.  If you’re lucky, your instrument will be smarter than you.  Sometimes the software might notice that something is wrong and stop the analysis run.  If it’s not….you’ll come back to a broken syringe plus a lack of data.

screw

If you have any fun or interesting troubleshooting tricks that have never steered you wrong let me know!  I’m always on the hunt for new ideas, and if I get enough, we might do a part 2 later.  Having as many tools in your troubleshooting tool belt as possible is so beneficial, and it’s one of the areas that we should all constantly be striving to improve.

Part 2: What Creates an Accurate Calibration Curve

Welcome back for the second week of Common Calibration Conundrums and Other Laboratory Queries!

 Before we get back into the science fun, I have an exciting announcement.  Bion Sciences now has an Instagram account!  Come follow along with us!  There will be blog notifications, access to our website, and photos of the Bion Sciences team in our natural, laboratory habitat!

@bionsciences605

 Part 2: What Creates an Accurate Calibration Curve

Now that we’ve covered how often you should calibrate an instrument, we should talk about how you pick standards to use for your curve and how many standards you should be using.

Think back to algebra when we first learned the equation for a line.  If your math teacher was anything like my math teacher, they drilled into your brain that 3 points are needed to accurately verify a line and the corresponding slope.  One point is simply a dot in space, and two points allow for too much swing in the correlation of the line, but three points……three points is really where the magic starts to happen!

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Don’t get overwhelmed with the math, I’ll simplify this for you!

The accuracy of your line, and therefore your results, improves dramatically as more data points are added to the line.  Think back to our puppy from last week.  If you only tell the puppy once a day, every day to potty outside, your results might be somewhat….questionable.  Now imagine you tell that puppy 3 times a day, every day, to potty outside.  The chances that puppy is going to catch on greatly improve!  The same goes for your instruments.

When it comes to calibration points, more is always better.  Again, there is no such thing as over calibrating an instrument!

The more data points you provide the instrument, the accuracy of the answers the instrument provides you will also improve.  The only issue that arises from more calibration standards is the time it takes to analyze each standard.  It’s important to find a balance between the most accurate curve you can produce and managing the time restrictions inside your lab.

To deal with time restrictions and busy schedules, sometimes improving your accuracy might involve decreasing the number of calibration points.  (Cue massive shock and awe as I appear to contradict everything I’ve said up to this point! 😊)

Let me give you an example.  Suppose you run 10 calibration standards….but because it takes several hours to build that impressive calibration curve you only calibrate your instrument every other month.  By the end of the second month, how true do you think those 10 data points are….I would argue they probably aren’t accurate anymore.  Instead, what if you ran 5 points once a week, or 3 points every day??  A smaller, more current curve will almost certainly produce more accurate data.  In the world of the laboratory, accuracy is the name of the game!

wyatt

So, you’re staring at a list of calibration standards and you find yourself wondering, “How do I figure out what to order?!”

A good rule of thumb is that your calibration standards should “hug” your expected value.  For example, if your anticipated answer is 3ppm, you wouldn’t want to make a curve using points 0.5ppm, 1.0 ppm, and 1.5 ppm.  You also wouldn’t want to use standards that all have values above your expected answer….meaning that 5.0ppm, 8.5ppm, and 12.25ppm also wouldn’t make a good curve for a value of 3ppm.

For an expected answer is 3ppm, I might select standards with values of 1.0 ppm, 2.5ppm, and 5.0ppm.  Typically, the wider the range of expected answers, the larger the range of standards should be.  Remember, your values need to be hugged by calibration points, not left to fend for themselves on the outskirts of your curve.  Every once in a while you might have a stray value that exceeds the boundaries of your calibration points, and that’s fine….every once in a while!  On the day-to-day and with your typical samples though, your results will be most correct if they are contained within the confines of your calibration data points!

Next week will be, Part 3: How to Know if Your Calibration Curve is Correct.  It’s Big Bang  Theory-themed so be sure to keep your eyes peeled for that!  In the meantime, if you have any questions about this week’s post or any ideas for future posts but sure to leave a comment and let me know!

I’ve Got A Brand New Blog

I was asked to start writing a science blog for work.  I’m not sure how much interest there will be, or how interested any of my current readers might be in this info, but I thought I might start sharing them here as well.

A few fun facts and some science knowledge never hurt anyone after all!  Currently, the plan is that I’ll post for work weekly.  That might taper off, but we have some events coming up and we wanted to drum up some interest and talking points with some customers before the events.  I will also be keeping up on my “personal” blog posts….which I have been bad about but hopefully all of this extra blogging will keep me on a schedule!

So….without further ado….I present my new blogging topic–

Common Calibration Conundrums and Other Laboratory Queries

Hey!

I’m coming at you to discuss some common science questions and issues I get asked in the lab frequently.  I thought I would start with a little mini-series on calibration issues, and then hopefully we can move on to other issues and questions you face in the lab on a daily basis.

If there is a specific topic or question you liked me to address, just leave a comment on this post and I’ll get back to you!

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Part 1: When to Calibrate

You should calibrate as often as practically feasible for your laboratory process and timelines!  It will not hurt your instruments to calibrate them too often, but it will hurt your results if you do not calibrate often enough.

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I know you might think that calibrating often is a waste of time…….and you’re busy…and the plant operators want their results…and the results seem fine so you’ll just ignore recalibrating your instruments until something bad happens.

Just take a minute and think about all the parameters around your instruments that change….even weekly.

Did you consider factors like-

  • Did you change mobile phase?
  • Standards will gradually degrade over time.
  • Wear and tear on the instrument components themselves

Even one of those small changes can compound and lead to catastrophic effects on your results over time.

Calibrating an instrument is a bit like potty training a new puppy.  Puppies only know what you tell them.  Imagine you tell the puppy one day to go outside.  The puppy might remember that knowledge for a day….maybe two.  Eventually, if you don’t remind the puppy what good behavior is, that puppy is going to forget.  When that happens, you’re going to come home to a disaster zone!!

Instruments only know what area counts corresponds to want concentration because you tell them….with standards and a calibration curve!  The instrument might be able to hold onto that curve and that knowledge for a day….or two, but eventually it’s going to drift too far to be accurate.  When that happens you wouldn’t be able to supply anyone with valid data, and you’ll end up behind a backlog of samples trying to figure out where it all went wrong.

I’ll be covering more about calibration data in the next couple posts so be sure to keep an eye out for those!  In the meantime, if you have any specific questions or you would like me to cover another lab related issue you find yourself facing, don’t hesitate to contact me about it!