More Relevant Than Ever; 65 Years and Counting

As McCrone Associates (MA) celebrates its 65th anniversary, our core business is perhaps more relevant now than it was at our inception. To understand why, it helps to review our core service and its value to you, our client. MA scientists use their scientific expertise, experience, and skills to solve development and production related materials problems using investigative analysis: the use of microanalytical techniques to identify contaminants and/or other unknown materials. We often encourage you to send known samples of the potential sources for comparison with your problem unknown sample, as final confirmation that you identified the root cause. Ultimately, our results are often used in root cause investigations of product development or production problems.

Importantly, investigational analyses conducted to identify unknown materials do not involve routine or compendial testing. Routine screening or formulation type testing follow predetermined or prescribed analytical protocols to test whether a sample meets predetermined specifications. Testing also commonly measures the concentrations of predetermined components of a material. The expected result of a test is a tabulated report of the component concentrations and the uncertainties associated with the measurements.

Fundamental to these different approaches is the concept of particle analysis versus bulk compositional analysis. As it happens, product failures, contaminants, or defects originate at the small scale, often at the microscopic scale; a size range requiring some form of magnification in order to locate. This is true regardless of product type as it is the nature of materials. Once a contaminant is visualized it is isolated so that the identification is not diluted by the overall normal portion of the product. It is these first steps that are the detective work, finding and isolating the real material of interest for identification. After isolating particles or microscopic portions of defects, the analysis is not too different from bulk analysis methods. One question that comes up occasionally is whether the concentration of the contaminants can be determined. The answer is no, primarily because the mass of all the contaminants’ particles in the bulk product relative to the mass of the bulk product is not known. Protocols to collect all contaminants and weigh them relative to the mass of the entire product rarely exist.

Also fundamental to the particle approach is visualization of the objects of interest. At MA’s founding, Dr. Walter McCrone utilized an elegant mature analytical tool of the time: the polarized light microscope. Polarized light microscopy can quantitatively identify materials as small as the tens of micrometers size range. At the time, the particle approach set MA apart from other analytical laboratories because the question has always been what is the root cause of the problem; bulk analytical approaches do not address the question sufficiently, even though new instrumentation and methods have vastly improved limits of detection. Understanding part per million or part per billion concentrations of trace elements in a bulk analysis only happens when unexpected objects containing those components can be visualized, isolated, and identified.

MA now uses several cutting edge instruments to more rapidly and quantitatively identify elemental and organic compounds, in some cases as small as the nanometer size range. However, light microscopy is always a foundational starting point for MA’s investigational analyses. Visualizing the problem using optical microscopy provides exceptionally compelling evidence to collection of corroborating analyses used to identify particles and defects of interest. This capability still sets MA apart from our competition. It fact, it is essential, particularly as product materials become more sophisticated and complex with the inclusion of nanomaterials, and with increased reliance on remote-controlled production automation. There is often a presumption that production proceeds without issue, in spite of relying on complicated, amazing engineering. Showing you the particles or defects of interest along with the corroborating cutting edge microanalyses strengthens your confidence in our characterization and identification findings.

Our staff of expert scientific detectives are ready for your next investigational challenge.


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