"Reducing Lab Stress With Analytical Solutions To Analytical Problems"

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Vol. 3, No. 1.  January, 2014

Writing the Perfect Method: Part 1

Improving Your Lab's Workflow

Writing the Perfect Method!

Over the next several months we will provide a brief summary of what makes one method better than another.   Your goal should always be to write a perfect method, even if you aren't always successful!

We will consider the following sections that are common in many chromatographic methods:

• Scope/Purpose
• Reagents, Solutions, and Supplies
• Equipment
• Columns
• Operating Conditions
• Preparation of Standards
• Preparation of Samples
• Analysis Procedure
• Quality Control
• Calculations
• Reporting
• Being a Good Chromatographer

Le's start with
Part 1: Scope and/or Purpose:
Yes, this is a GC or LC method, but there is more information that the user (and an auditor) needs to know.  Are there limits to what this method can do, or only certain products that can be analyzed?  What kind of results will be generated? 

Do:

• List all the samples/products that were evaluated during development and/or validation.
• Specify the range of analyte concentrations that can be determined (purity, minor component, trace level, etc.)
• List restrictions if they are known (samples that cannot be analyzed with this method)

Do Not:

• List other samples or analytes if you have not evaluated them.  Methods are not suggestions for future work, but summaries of past successes (and failures).
• Assume anything about who reads and uses the method.  If they need to know, you need to put it in the method.

Before we wrap up this section, a comment about how you write methods is important.  Above we mentioned that you should consider how an auditor would read the method.  Now, our focus is not on regulatory issues here, but they are important in many labs.  More importantly, many of those same issues that a good auditor looks for are the same issues that differentiate a great method from a bad one - can anyone use this method, do we know what samples can be analyzed, do we know all the procedures needed needed for success, etc?  We visit too many labs where the previous analyst knew all the "secrets" to getting the method to work, but they were never written into the method.  If that analyst is gone, the lab is starting over.  If you don't want to be put in that situation, make sure that you don't put others in that situation with the methods that you write.

Would you like us to evaluate your methods, or comment about this topic?  Contact us.

"Mistakes are, after all, the foundations of truth, and if a man does not know what a thing is, it is at least an increase in knowledge if he knows what it is not."

– Carl Jung