Analyzing substances through opaque barriers using Raman spectroscopy

Agilent's LC/MS and GC/MS instruments accurately analyze pesticide residues in foods

Raman spectroscopy is a popular method for chemical identification as the rich spectral information obtained from a measurement can be used like a 'chemical fingerprint'. This means that when a Raman spectrum is obtained it can easily be matched to a known chemical (or mixture of chemicals) from a spectral library. This capability enables a wide array of applications, including first responders dealing with chemical spillages, explosive experts analysing the contents of a potential improvised explosive device (IED) and customs officers searching for controlled substances (e.g. fentanyl). Raman methods also help to assure the quality of pharmaceutical drugs, whether verifying the identity of raw materials at the beginning of manufacturing, or checking the dosage level of tablets and capsules at the end of the production line.

Identifying hazardous materials through containers

NEED_ALT Figure 1. Resolve identifies chemicals through a wide range of colored and opaque container materials.

Handheld Raman systems have been used extensively in hazmat, security and counter-terrorism applications for more than a decade. Existing products on the market are able to identify unknown chemicals either by a direct line-of-sight or when the material is contained within thin, transparent bottles and plastic bags.

Cobalt Light Systems - now part of Agilent - launched the Resolve handheld Raman system in March 2016. Resolve uses spatially offset Raman spectroscopy (SORS), a new-generation technique that identifies unknown hazardous and contraband materials inside opaque containers such as colored plastics, dark glass, paper, card, wrapping, sacks and fabrics. The system identifies substances from comprehensive libraries of 1000's of chemicals, including explosives, toxic industrial chemicals, chemical warfare agents, and narcotics. Operators can identify a container's contents without compromising the integrity of the packaging, reducing the risk of unknown chemical release. Potentially sensitive materials (e.g. explosives) remain undisturbed, evidence is more easily preserved, and time spent by first responders in the "hot zone" (in protective gear) can be used more efficiently.

Resolve is already deployed worldwide in hazmat response, customs screening, investigation, security, counter terrorism and policing, as well as military applications.

Through-barrier Raman in pharma QC

Figure 2. RapID verifying the identity of citric acid through the sack in a pharmaceutical incoming goods warehouse.

SORS was developed by Cobalt's Chief Scientific Officer, Prof. Pavel Matousek, at the Rutherford Appleton Laboratory in the UK. The company's first commercially-available SORS system, RapID, is used for through-container raw material ID verification in pharmaceutical manufacturing. The system is compatible with most APIs and excipients and works through the most common incoming containers, including multi-layer paper sacks, plastic tubs and colored glass bottles. RapID enables 100% ID testing for all incoming containers by removing the need to take samples. This reduces operator time and sample-handling booth usage, removes the risk of operator exposure to high-potency APIs and prevents cross-contamination, particularly in sterile manufacturing.

Airport security - Liquid explosive detection

Figure 3. Insight200M screens liquids, aerosols and gels in all common container

Through-barrier SORS technology is also deployed at airports across the EU, Asia and Australasia as the engine in Cobalt's 'Insight' range of liquid explosive detection systems (LEDS). Insight systems offer the lowest false alarm rate of any ECAC certified system and are in use for liquids, aerosols and gels (LAGs) screening at more than 70 airports in Europe, including 8 of the top 10 hub airports.

Pharmaceutical tablet and capsule testing

Figure 4. TRS100 analyzes the uniformity of content in intact tablets and capsules.

Cobalt has also developed transmission Raman spectroscopy (TRS) technology and the TRS100 system for content uniformity testing of pharmaceutical tablets and capsules. Content uniformity tests check that a tablet or capsule contains the correct amount of active ingredient and are a critical step in pharmaceutical manufacturing. Transmission Raman accurately analyzes whole tablets and capsules, and works through tablet coatings and capsule materials. Pharma companies are increasingly using the TRS100 in R&D and production environments. TRS is attractive because of the benefits it offers in speed of measurement, lack of preparation time, avoidance of wet chemistry and the significant cost that can be saved per batch test.

The future of Raman at Agilent

Figure 5. The future Oxfordshire, U.K. headquarters of Agilent Raman spectroscopy

Agilent acquired Cobalt Light Systems in July 2017. Oxford is now Agilent's global center for Raman spectroscopy and the business will soon be moving to a large new facility. The additional space will allow for significantly expanded R&D and production facilities, as the business focuses on an ever-growing number of applications for its unique Raman capabilities.

Find out more:

TRS100 - Quantitative pharmaceutical tablet and capsule testing

AGILENT'S RAMAN SPECTROSCOPY SOLUTIONS

Agilent Technologies acquired Cobalt Light Systems, an Oxford UK-based Raman spectroscopy company, in July 2017.

Cobalt's unique SORS and TRS technologies are used for handheld chemical identification, airport security liquids screening and pharmaceutical quality control.

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