Terahertz time-domain spectroscopy for measurement of particle sizes of fexofenadine hydrochloride

Anna Sadloňová, Vojtech Kresalek, Tomas Bata

Abstract

Time domain spectroscopy is one of the new methods of terahertz radiation used for wide spectrum of the industry. More extended sector is the security system much like the sector of the medicine. The main focus is orientated to detection and identification of the substances. This study is focused on the measurement of the particle size of pharmaceuticals. The characteristic absorption features will be studied experimentally by Terahertz time-domain spectroscopy. The results are identified for processing by one of the statistical method usable for such variable groups. The three samples of the pharmaceutical– Fexofenadine Hydrochloride (antihistamine) will be compared between themselves. Mentioned samples are supplied by different suppliers. The main focus will be put on the pharmaceutical differences of the same pharmaceutical that are commonly available on the markets. Terahertz time-domain spectroscopy setup was used to measure absorbance spectra of each sample in the range from 1 THz to 3 THz (it was used the device TPS Spectra 3000 produced by TeraView Ltd . The device that belongs to the first commercial machine developed in this company for measurement of the substances by transmission spectroscopy method.). During the testing was used the vacuum for purging the measurement chamber from water vapors.

This study was performed using TeraView's Spectra 3000 system. (TeraView, Cambridge, UK)

TeraView Continues to Make Waves at IRMMW-THz 2014

TeraView invites you to visit us at IRMMW-THz 2014!

Dr. Philip Taday and Rob May will both be attending the event, with Rob May giving a keynote talk on Monday the 15th of September - 11:30 in the Tuscon Room:

Terahertz Car Paint Thickness Sensor: Out of The Lab and Into the Factory

Don't miss out on this opportunity to learn more about TeraView's recent development and applications!

TeraView will be at Booth #21

If you would like to pre-arrange a meeting, please e-mail Dr. Phil Taday.

Broadband Terahertz Sensing on Spoof Plasmon Surfaces

Binghao Ng , Stephen M. Hanham , Jianfeng Wu , Antonio I. Fernández-Domínguez , Norbert Klein , Yun Fook Liew , Mark B.H. Breese , Minghui Hong , and Stefan A. Maier

Abstract

In this paper, we show that broadband spectral data can be experimentally extracted from corrugated metallic surfaces consisting of a linear array of subwavelength grooves supporting tightly confined spoof plasmons. Using a combination of the scattering edge coupling method and short-time Fourier transform, we are able to discern the group velocity characteristics of a spoof plasmon pulse which in turn allows for the extraction of broadband dispersion data from 0.4 THz to 1.44 THz in a single measurement. Refractive index sensing of various fluids is demonstrated at microlitre volume quantities by monitoring changes in not only the dispersion relation but also the frequency dependent attenuation of the spoof plasmons. This gives information about both the real and imaginary part of the refractive index of an analyte, indicating the potential for spoof plasmon surfaces to fully characterise substances in the terahertz regime. Lastly, we show that the strong electromagnetic field confinement near the effective spoof plasmon frequency allows for surface enhanced absorption spectroscopy, demonstrated here with α-lactose monohydrate powder. This allows us to take a more spectroscopic approach to THz sensing whereby substances can be uniquely identified by their spectral fingerprints. The enhanced light-matter interactions that occur in the vicinity of the spoof plasmon surface allows for a more efficient use of the limited power of current terahertz sources. Together with the ability to integrate spoof plasmon surfaces with microfluidics and to freely design its electromagnetic properties, we believe that these surfaces can be a very versatile platform on which chip-scale terahertz sensing can be performed.

This study was performed using TeraView's Spectra 3000 system. (TeraView, Cambridge, UK)

Full Article: http://pubs.acs.org/doi/abs/10.1021/ph500272n

Split-ring resonators manufactured on conductive layer by selective laser ablation

Paweł Koziol ; Arkadiusz J. Antończak ; Patrycja E. Szymczyk ; Bogusz Stępak ; Łukasz Łazarek ; Michał R. Wójcik ; Michał Walczakowski ; Krzysztof M. Abramski

Abstract

In this paper an alternative method of manufacturing SRR structures through the selective removal of a thin layer of silver-palladium deposited on the surface of the Al2O3 ceramic by laser ablation process using nanosecond Nd:YAG laser (1064 nm) was presented. The SRR structures array were subject to transmittance measurements using the TDS (Time Domain Spectroscopy). Both electric and magnetic resonances were observed at frequencies determined by the structural parameters of the SRR. In case of the E field perpendicular to an SRR structure and one resonance area for 0.56 THz with the E field parallel to the structure, two characteristic resonant dips for 0.31 THz and 0.62 THz were obtained. Studies have confirmed that using selective laser removal process enables the preparation of the resonant structure in the range of THz. © (2014) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.


This study was performed using TeraView's Spectra 3000 system. (TeraView, Cambridge, UK)

Full Article: http://www.sciencedirect.com/science/article/pii/S0939641114002203

CLEO: 2015 - Laser Science to Photonic Applications

The submissions for CLEO: 2015 (12-14 May 2015 in San Jose, California, USA) Abstract and Summary Submission Deadline will be 16 December 2014, 12:00 EST (17:00 GMT)

CLEO: 2015 is well known for its high quality, peer-reviewed research, and bridges fundamental science all the way through to technology development and uses of technology and applications. 

More information about CLEO: 2015 can be found on the website at www.cleoconference.org.