New reliable Raman collection system using the wide area illumination (WAI) scheme combined with the synchronous intensity correction standard for the analysis of pharmaceutical tablets

Kim, Minjung; Chung, Hoeil; Woo, Young-Ah; Kemper, Mark S.

doi:10.1016/j.aca.2006.07.036

Cited by 84 publications

(44 citation statements)

References 15 publications

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“…One possible explanation for these results is the relatively larger sampling area (283.4 μm 2 ) of optical fiber excitation Raman system as compared with that of benchmounted Raman system (2.0 μm 2 ), resulting in more Raman information being retrieved from the heterogeneous sample. 35 Therefore, our results clearly showed the advantage of the optical fiber excitation Raman spectroscopy as developed in this paper over the bench-mounted Raman spectroscopy for characterizing heterogeneous matrix.…”

Section: Bench-mounted Raman Spectroscopy/opticalmentioning

confidence: 67%

Monitoring the cementitious materials subjected to sulfate attack with optical fiber excitation Raman spectroscopy

et al. 2013

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Abstract. Formation of ettringite and gypsum from sulfate attack together with carbonation and chloride ingress have been considered as the most serious deterioration mechanisms of concrete structures. Although electrical resistance sensors and fiber optic chemical sensors could be used to monitor the latter two mechanisms on site, currently there is no system for monitoring the deterioration mechanisms of sulfate attack. In this paper, a preliminary study was carried out to investigate the feasibility of monitoring sulfate attack with optical fiber excitation Raman spectroscopy through characterizing the ettringite and gypsum formed in deteriorated cementitious materials under an optical fiber excitation + objective collection configuration. Bench-mounted Raman spectroscopy analysis was also conducted to validate the spectrum obtained from the fiber-objective configuration. The results showed that the expected Raman bands of ettringite and gypsum in the sulfate-attacked cement paste can be clearly identified by the optical fiber excitation Raman spectrometer and are in good agreement with those identified from bench-mounted Raman spectrometer. Therefore, based on these preliminary results, it is considered that there is a good potential for developing an optical fiber-based Raman system to monitor the deterioration mechanisms of concrete subjected to sulfate attack in the future.

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Section: Bench-mounted Raman Spectroscopy/opticalmentioning

confidence: 67%

Monitoring the cementitious materials subjected to sulfate attack with optical fiber excitation Raman spectroscopy

et al. 2013

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“…[18] The WAI scheme used in this study has been developed by Kaiser Optical Systems (Ann Arbor, MI, USA). An excitation laser (785 nm, diode laser) was magnified to form a circular illumination area with a diameter of 6 mm (area 28.3 mm 2 ), so as to cover a large sample area.…”

Section: Methodsmentioning

confidence: 99%

“…This could result from the fact that WAI is superior in representing correct sample compositions without localized features and spectral reproducibility, as previously argued. [18] To investigate the difference in sample representation between the conventional and WAI schemes, we examined triplicate spectra (normalized spectra) collected for the same sample. If spectral variation existed among triplicate spectra, this would be indicative of an unsuccessful sample presentation due mainly to sample inhomogeneity relative to the small size of the laser spot and unsatisfactory spectral reproducibility.…”

Section: Principal Component Analysismentioning

confidence: 99%

Improving Raman spectroscopic differentiation of the geographical origin of rice by simultaneous illumination over a wide sample area

Kim

Lee

Chung

et al. 2008

J Raman Spectroscopy

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This research substantially improved the differentiation of rice of two geographical origins utilizing a wide area illumination (WAI) scheme capable of collecting Raman spectra of a large sample area (28.3 mm 2 ) synchronously without sample rotation. For the purposes of comparison, we also employed a conventional scheme in which the laser illuminated only small areas. Principal component analysis (PCA) was used to differentiate the two geographical origins using the Raman spectra collected through both the conventional and the WAI schemes. The WAI scheme exhibited improved differentiation, primarily due to the fact that the WAI scheme could efficiently produce Raman spectra with a more reliable sample representation, as well as better reproducibility. The spectral feature obtained using the conventional scheme appeared to be more variable; however, this variation resulted more from unsuccessful sample representation than from an actual change in the sample composition. We conclude that the WAI scheme has a good potential for the analysis of diverse agricultural samples that consist of solid granules.

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“…The WAI scheme applies the laser beam to a wide area of the sample for Raman spectral collection (6 mm laser spot with a focal length of 248 mm). [13] Any unwanted spectral variation originating from sample placement or from varying surface shape can be greatly reduced because of the long focal length. Additionally, by covering a large sample area, the sample represented by the Raman measurement is more reliable.…”

Section: Introductionmentioning

confidence: 99%

Wide area illumination Raman scheme for simple and nondestructive discrimination of seawater cultured pearls

Park

Kim

Park

et al. 2009

J Raman Spectroscopy

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Raman spectroscopy, along with discriminant partial least squares (PLS), was successfully used to discriminate among three different groups of cultured pearls (fresh water, Akoya and South seawater). The discrimination between Akoya and South seawater pearls using XRF (X-ray fluorescence), one of the most frequently adopted analytical methods in pearl analysis, has been especially difficult owing to their similar mineral compositions. The selective Raman features helped in effectively discriminating between these two pearl groups. The difference in the intensities of the CaCO 3 bands of Akoya and South seawater pearls provided a valuable clue. Along with the selective Raman feature, a reproducible Raman spectral collection achieved using a wide area illumination (WAI) scheme played an important role in the determination of the pearl groups, although the pearls were hard-surfaced, round, solid samples of different sizes and surface shapes. Unwanted spectral variation originating from sensitivity to sample placement relative to the focal plane and from unsuccessful sample representation due to the probing of a localized area, factors that could possibly deteriorate Raman reproducibility, were substantially lessened using the WAI scheme. ATR (attenuated total reflection) IR spectroscopy requiring direct contact with the pearl could be inadequate for discrimination or classification where large numbers of repeating and reproducible measurements are required. Copyright

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New reliable Raman collection system using the wide area illumination (WAI) scheme combined with the synchronous intensity correction standard for the analysis of pharmaceutical tablets

Cited by 84 publications

References 15 publications

Monitoring the cementitious materials subjected to sulfate attack with optical fiber excitation Raman spectroscopy

Monitoring the cementitious materials subjected to sulfate attack with optical fiber excitation Raman spectroscopy

Improving Raman spectroscopic differentiation of the geographical origin of rice by simultaneous illumination over a wide sample area

Wide area illumination Raman scheme for simple and nondestructive discrimination of seawater cultured pearls

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