Topic

Richard Crocombe is the Principal at Crocombe Spectroscopic Consulting, specializing in miniature and portable spectroscopic instrumentation.

Brooke W. Kammrath is a Professor at the University of New Haven and Assistant Director of the Henry C. Lee Institute of Forensic Science.

Pauline Leary is a CBRNE SME at Noble, specializing in miniature and portable spectroscopic instruments.

Articles

There is a growing desire among spectroscopists for having instruments
small enough to be taken to the sample, as opposed to bringing the sample
to the instrument. The result is that Raman spectrometers are becoming
more miniaturized. Because these instruments come at a lower cost and offer distinct advantages over traditional spectrometers, the expectation is that a rapid expansion of when these instruments are applied will come forthwith. We offer a preview of how future miniaturized Raman spectrometers might look.

Portable Raman Spectrometers: How Small Can They Get?

Jerome Workman Jr. serves on the Editorial Advisory Board of Spectroscopy and is currently with Unity Scientific LLC. He is also an adjunct professor at Liberty University and U.S. National University. He can be reached at jworkman04@gsb.columbia.edu.

This article provides a convenient summary of portable and handheld spectroscopy techniques, outlining the most prominent types of compact instruments for both atomic and molecular spectroscopy.

A Brief Survey of Handheld and Portable Instruments Used in Spectroscopy

Industry leaders answer this question: In what area will spectroscopy see the biggest growth in the next five years?

Overcoming Struggles in Implementing Handheld Raman Spectroscopy Across the Manufacturing Line

A simple method for extraction and concentration of trace organic compounds found in water for gas chromatography-mass spectrometry (GC-MS) analysis was developed. The method used 25 and 45 mL glass vials with a 5-10 µm thick polymer coatings for extraction of analytes from 20 and 40 mL water samples, respectively. Analytes were subsequently transferred from the polymer coating into an organic solvent, which was reduced in volume to 200-400 µL for analysis. A 10-20 µL sample from the vial was transferred to a tiny coiled stainless steel wire filament using a micro-syringe, or by dipping the coil into the sample. After air evaporation of the solvent, the coil was inserted into the heated injection port of a portable GC-MS system where the analytes were desorbed. Injection using the coiled wire filament eliminated sample discrimination of high boiling point compounds, and minimized system contamination caused by sample matrix residues. The GC-MS contained a new resistively heated column bundle that allowed elution of low-volatility compounds in less than 4 min. Analyses of organochlorine pesticides, polycyclic aromatic hydrocarbons, polychlorinated biphenyl congeners, pyrethroid insecticides, phthalate esters, and n-alkanes in water and wastewater samples were accomplished for low ppb concentrations in less than 10 min total analysis time.

Analysis of Organic Compounds in Water Using Unique Concentration–Injection Techniques for Portable GC–MS

The Versatility of Portable Raman in Process Development

Discrimination of Bacterial Growth Media Using Portable Raman Spectroscopy with Background Fluorescence Subtraction

Fast and Selective Detection of Trigonelline, a Coffee Quality Marker, Using a Portable Raman Spectrometer

Portable instrumentation for Raman spectroscopy has rapidly evolved over the last decade, where sample testing that once occurred in the laboratory is now executed in the field (e.g. warehouse).   Portable Raman spectroscopy is a powerful technique for the rapid identification of diversely sourced raw materials used in pharmaceutical processing.  In addition to portability; reduced cost, rapid data acquisition and ease of use make this powerful technique attractive and accessible to both expert spectroscopists and non-specialists.  In most cases, the method development can be easily accomplished in the laboratory after which the instrument and methods are transferred to field for sample analysis or warehouse areas for inspection of incoming raw material.  Qualitative Raman methods for identification of raw materials typically utilize spectral libraries for sample to standard comparison.  When developing Raman spectral libraries for raw material identification, great care is required when considering critical factors (e.g. instrument type, Raman capability, container type, container interference, background interference, material variability) that can potentially influence the identity of the material.  This paper discusses portable Raman techniques and approaches for raw material identification, as well as key considerations for developing and validating Raman spectral libraries.

Developing Portable Raman Spectroscopy Methods for Identification of Raw Materials Used in Pharmaceutical Development and Manufacturing

Raman spectroscopy is a well-suited spectroscopic technique for process development and control within development labs in chemical, pharmaceutical, and other industries. This article demonstrates the utility of portable Raman spectroscopy as a simple and versatile tool for in-situ monitoring of reactions using univariate analysis such as peak trending, as well as multivariate analysis approaches to predict the end point of chemical reactions. Using portable Raman systems allows users to make measurements in the lab, but also serves as a proof of concept for the Raman measurements to be implemented at-line or on-line in small pilot plants or large scale production sites. For known reactions that are repetitively performed, or for continuous online process monitoring of reactions, the present approach provides a convenient solution for process understanding and the basis for future implementation.

The availability of quality drugs is crucial in the event of a pandemic. Here, we report our pilot efforts to perform rapid screening of anti-infective drugs for confirmation of drug product quality using near infrared and Raman library methods. The methods reported are nondestructive towards the sample and are designed to facilitate rapid physical testing of drugs at the point of use or in a field setting. We built a representative library through voluntary collaboration with six different manufacturers of antibiotic and antiviral drugs. The drugs supplied by these manufacturers are representative of imported U.S. FDA approved finished products. We successfully transferred the spectral libraries from laboratory-based instruments to field-deployable handheld near infrared and Raman instruments and challenged the library methods using independent samples from different batches.

Portable and Handheld Spectroscopy