Investigation of factors affecting isolation of needle-shaped particles in a vacuum-agitated filter drier through non-invasive measurements by Raman spectrometry (original) (raw)
Related papers
Applied Spectroscopy, 1993
Raman analyses of fluid inclusions can yield quantitative information on composition (from peak areas and heights) and density (from peak position and width). In this study, we examine the effect of instrumental spectral resolution on the ratios of these spectral parameters, and the selection of appropriate integration limits for the determination of peak areas in the CO2-CH4-N2 system. Spectral resolution was varied from about 1 to 9 cm ' by co-varying the widths of all spectrometer slits. Changes in resolution produced a modest effect on peak-area ratios and a significant effect on peak-height ratios. Measured peak-widlh ratios varied strongly as a function of the spectral resolution. In addition, we observed a moderate shift in the measured peak position of Nz, which can be related to the asymmetry of the band. These results indicate that accurate analysis requires careful attention to the selection of quantification factors, especially if the selected values were derived from studies at different spectral resolutions. Another factor that can have a significant effect on the calculated compositions of CH 4-and H2-bearing fluid mixtures is the band broadening that occurs with increasing pressure.
Current Directions in Biomedical Engineering, 2017
The particle generation of medical implants and drug coated balloons (DCB) is evaluated by simulating the implantation process and collecting the released particle material. In addition to size and particle counts their material composition is of interest. Raman spectroscopy and micros-copy are established methods for chemical identification. For the manual analysis of the particles different filter or rather background materials are suitable because different require-ments in height and intensity of the spectra can be compen-sated by the user. The aim of this study was to find suitable background materials for automatic particle identification. Raman analysis of background and spherical polystyrene standard particles on filters and plain surfaces was performed manually to receive evaluable spectra for automation. Auto-matic analysis was done by a) single-point spectrum meas-urement using the coordinate list of all particles, and b) scan-ning a large sample area pixel by pixel measu...
Sensing and imaging, 2011
This article reviews current scientific literature focusing on Raman spectroscopy modalities that have been successfully applied to the detection of biological samples in aqueous suspensions and in aerosols. Normal Raman, surface enhanced Raman scattering, coherent anti-stokes Raman scattering, resonance Raman and UV-Raman spectropies, allow the detection of biological samples in situ in the near field and as well as in the far field at standoff distances. Applications span from fundamental studies to applied research in areas of defense and security and in monitoring of environmental pollution. A primary focus has been placed on biological samples including bacteria, pollen, virus, and biological contents in these specimens, in suspensions, and in aerosols. Several Raman spectroscopy studies have been reviewed to show how various modalities can achieve detection in these biosystems. Current data generated by our group is also included. Necessary parameters used to accomplish the detection and data analysis, which could also be used to interpret the results and to render the methodologies robust and reliable, are discussed.
Applied Spectroscopy, 1999
We describe the ® rst application of dispersive Ram an spectroscopy using a diode laser exciting at 780 nm and a charge-coupled device (CCD) detector to the noninvasive, on-line determination of the biotransform ation by yeast of glucose to ethanol. Software was developed which automatically rem oved the effects of cosmic rays and other noise, normalized the spectra to an invariant peak, then rem oved the``baseline'' arising from interference by¯uorescent impurities, to obtain the``true'' Raman spectra. Variable selection was automatically perform ed on the param eters of relevant Raman peaks (height, width, position of top and center, area and skewness), and a small subset used as the input to cross-validated m odels based on partial least-squares (PLS) regression. The m ultivariate calibration m odels so form ed were suf® ciently robust to be able to predict the concentration of glucose and ethanol in a completely different fermentation with a precision better than 5%. Dispersive Raman spectroscopy, when coupled with the appropriate chemom etrics, is a very useful approach to the noninvasive, on-line determination of the progress of m icrobial fermentations.
Analytical and Bioanalytical Chemistry, 2016
Adoption of Quality by Design (QbD) principles, regulatory support of QbD, process analytical technology (PAT), and continuous manufacturing are major factors effecting new approaches to pharmaceutical manufacturing and bioprocessing. In this review, we highlight new technology developments, data analysis models, and applications of Raman spectroscopy, which have expanded the scope of Raman spectroscopy as a process analytical technology. Emerging technologies such as transmission and enhanced reflection Raman, and new approaches to using available technologies, expand the scope of Raman spectroscopy in pharmaceutical manufacturing, and now Raman spectroscopy is successfully integrated into real-time release testing, continuous manufacturing, and statistical process control. Since the last major review of Raman as a pharmaceutical PAT in 2010, many new Raman applications in bioprocessing have emerged. Exciting reports of in situ Raman spectroscopy in bioprocesses complement a growing scientific field of biological and biomedical Raman spectroscopy. Raman spectroscopy has made a positive impact as a process analytical and control tool for pharmaceutical manufacturing and bioprocessing, with demonstrated scientific and financial benefits throughout a product's lifecycle.
Handheld spectrophotometers Raman spectroscopy Spatially offset Raman scattering comparison of quantitative performances Quantitation through packaging A B S T R A C T Handheld Raman spectroscopy is actually booming. Recent devices improvements aim at addressing the usual Raman spectroscopy issues: fluorescence with shifted-excitation Raman difference spectroscopy (SERDS), poor sensitivity with surface enhanced Raman scattering (SERS) and information only about the sample surface with spatially offset Raman spectroscopy (SORS). While qualitative performances of handheld devices are generally well established, the quantitative analysis of pharmaceutical samples remains challenging.
Journal of Raman Spectroscopy, 2007
Raman spectroscopy with 1064 nm laser excitation is used here to identify the chemical composition of the extracts obtained from Pycnoporus sanguineus fungus, in comparison with the data produced from the red fungus itself. Polar and non-polar solvents were used to separate cinnabarin and ergosterol, respectively, the main components of each extract. The Raman spectra of the extracts are dominated by specific vibrational modes that can be related to these components; in the case of ergosterol the main bands are those assignable to CH stretching and deformation along with bands related to the aryl skeletal rings. The cinnabarin fraction, on the other hand, gives a Raman spectrum where the most important bands are those related to NH 2 bending (1510 cm −1 ) and C O quinonoid stretching (1647 cm −1 ) modes. The Raman spectrum obtained directly from the fungus shows similarity with the cinnabarin fraction, in agreement with the literature information from extracts that cinnabarin is the most significant component present in the red fungus. This result highlights the potential of Raman spectroscopic techniques for the monitoring of the fungus extraction process undertaken in small industries.