Raman spectroscopy method for subsurface detection of food powders through plastic layers

Sagar Dhakal; Kuanglin Chao; Jianwei Qin; Walter F. Schmidt; Moon S. Kim; Diane E. Chan; Abigail Bae

doi:10.1117/12.2262102

1 May 2017 Raman spectroscopy method for subsurface detection of food powders through plastic layers

Sagar Dhakal, Kuanglin Chao, Jianwei Qin, Walter F. Schmidt, Moon S. Kim, Diane E. Chan, Abigail Bae

Proceedings Volume 10217, Sensing for Agriculture and Food Quality and Safety IX; 1021706 (2017) https://doi.org/10.1117/12.2262102
Event: SPIE Commercial + Scientific Sensing and Imaging, 2017, Anaheim, CA, United States

Abstract

Proper chemical analyses of materials in sealed containers are important for quality control purpose. Although it is feasible to detect chemicals at top surface layer, it is relatively challenging to detect objects beneath obscuring surface. This study used spatially offset Raman spectroscopy (SORS) method to detect urea, ibuprofen and acetaminophen powders contained within one or more (up to eight) layers of gelatin capsules to demonstrate subsurface chemical detection and identification. A 785 nm point-scan Raman spectroscopy system was used to acquire spatially offset Raman spectra for an offset range of 0 to 10 mm from the surfaces of 24 encapsulated samples, using a step size of 0.1 mm to obtain 101 spectral measurements per sample. With increasing offset distance, the fraction of information from the deeper subsurface material increased compared to that from the top surface material. The series of measurements was analyzed to differentiate and identify the top surface and subsurface materials. Containing mixed contributions from the powder and capsule, the SORS of each sample was decomposed using self modeling mixture analysis (SMA) to obtain pure component spectra of each component and corresponding components were identified using spectral information divergence values. Results show that SORS technique together with SMA method has a potential for non-invasive detection of chemicals at deep subsurface layer.

Conference Presentation

Citation Download Citation

Sagar Dhakal, Kuanglin Chao, Jianwei Qin, Walter F. Schmidt, Moon S. Kim, Diane E. Chan, and Abigail Bae "Raman spectroscopy method for subsurface detection of food powders through plastic layers", Proc. SPIE 10217, Sensing for Agriculture and Food Quality and Safety IX, 1021706 (1 May 2017); https://doi.org/10.1117/12.2262102

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available