scholarly journals Estimation of multivariate detection limits of four quality parameters in licorice using MEMS–NIR spectrometry coupled with two sampling accessories

2015 ◽  
Vol 08 (05) ◽  
pp. 1550009
Author(s):  
Zhisheng Wu ◽  
Xinyuan Shi ◽  
Na Zhao ◽  
Yanling Pei ◽  
Manfei Xu ◽  
...  
Keyword(s):  
Fiber Optic ◽  
Detection Limits ◽  
Quality Parameters ◽  
Integrating Sphere ◽  
Model Assessment ◽  
Fiber Optic Probe ◽  
Geographical Regions ◽  
Optic Probe ◽  
Concentration Levels ◽  
Multivariate Detection

In this work, multivariate detection limits (MDL) estimator was obtained based on the micro-electro-mechanical systems–near infrared (MEMS–NIR) technology coupled with two sampling accessories to assess the detection capability of four quality parameters (glycyrrhizic acid, liquiritin, liquiritigenin and isoliquiritin) in licorice from different geographical regions. 112 licorice samples were divided into two parts (calibration set and prediction set) using Kennard–Stone (KS) method. Four quality parameters were measured using high-performance liquid chromatography (HPLC) method according to Chinese pharmacopoeia and previous studies. The MEMS–NIR spectra were acquired from fiber optic probe (FOP) and integrating sphere, then the partial least squares (PLS) model was obtained using the optimum processing method. Chemometrics indicators have been utilized to assess the PLS model performance. Model assessment using chemometrics indicators is based on relative mean prediction error of all concentration levels, which indicated relatively low sensitivity for low-content analytes (below 1000 parts per million (ppm)). Therefore, MDL estimator was introduced with alpha error and beta error based on good prediction characteristic of low concentration levels. The result suggested that MEMS–NIR technology coupled with fiber optic probe (FOP) and integrating sphere was able to detect minor analytes. The result further demonstrated that integrating sphere mode (i.e., MDL0.05,0.05, 0.22%) was more robust than FOP mode (i.e., MDL0.05,0.05, 0.48%). In conclusion, this research proposed that MDL method was helpful to determine the detection capabilities of low-content analytes using MEMS–NIR technology and successful to compare two sampling accessories.

Synthesis, performance and growth mechanism of silver nanoparticle coated SERS fiber probe

2019 ◽  
Vol 107 (3) ◽  
pp. 305
Author(s):  
Mengmei Geng ◽  
Yuting Long ◽  
Tongqing Liu ◽  
Zijuan Du ◽  
Hong Li ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Absorption Spectrum ◽  
Reaction Time ◽  
Growth Mechanism ◽  
Fiber Optic ◽  
Fiber Optic Probe ◽  
Visible Absorption ◽  
Fiber Probe ◽  
Surface Enhanced Raman ◽  
Optic Probe

Surface-enhanced Raman Scattering (SERS) fiber probe provides abundant interaction area between light and materials, permits detection within limited space and is especially useful for remote or in situ detection. A silver decorated SERS fiber optic probe was prepared by hydrothermal method. This method manages to accomplish the growth of silver nanoparticles and its adherence on fiber optic tip within one step, simplifying the synthetic procedure. The effects of reaction time on phase composition, surface plasmon resonance property and morphology were investigated by X-ray diffraction analysis (XRD), ultraviolet-visible absorption spectrum (UV-VIS absorption spectrum) and scanning electron microscope (SEM). The results showed that when reaction time is prolonged from 4–8 hours at 180 °C, crystals size and size distribution of silver nanoparticles increase. Furthermore, the morphology, crystal size and distribution density of silver nanoparticles evolve along with reaction time. A growth mechanism based on two factors, equilibrium between nucleation and growth, and the existence of PVP, is hypothesized. The SERS fiber probe can detect rhodamin 6G (R6G) at the concentration of 10−6 M. This SERS fiber probe exhibits promising potential in organic dye and pesticide residue detection.

Evaluation of Dry-Wet Transition in PEFC Under Load Changes Based on Laser Spectroscopy Using Fiber-Optic Probe

2019 ◽  
Vol 92 (8) ◽  
pp. 119-124
Author(s):  
Kosuke Nishida ◽  
Ryoga Nakauchi ◽  
Yuma Tabata ◽  
Toyofumi Umekawa ◽  
Masahiro Kawasaki
Keyword(s):  
Laser Spectroscopy ◽  
Fiber Optic ◽  
Fiber Optic Probe ◽  
Optic Probe

scholarly journals Longitudinal Raman Spectroscopic Observation of Skin Biochemical Changes due to Chemotherapeutic Treatment for Breast Cancer in Small Animal Model

2017 ◽  
Vol 2017 ◽  
pp. 1-9
Author(s):  
Myeongsu Seong ◽  
NoSoung Myoung ◽  
Songhyun Lee ◽  
Hyeryun Jeong ◽  
Sang-Youp Yim ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Animal Model ◽  
Raman Spectra ◽  
Fiber Optic ◽  
Animal Experiments ◽  
Small Animal ◽  
Fiber Optic Probe ◽  
Small Animal Model ◽  
Biochemical Compositions ◽  
Optic Probe

The cancer field effect (CFE) has been highlighted as one of indirect indications for tissue variations that are insensitive to conventional diagnostic techniques. In this research, we had a hypothesis that chemotherapy for breast cancer would affect skin biochemical compositions that would be reflected by Raman spectral changes. We used a fiber-optic probe-based Raman spectroscopy to perform preliminary animal experiments to validate the hypothesis. Firstly, we verified the probing depth of the fiber-optic probe (~800 μm) using a simple intravenous fat emulsion-filled phantom having a silicon wafer at the bottom inside a cuvette. Then, we obtained Raman spectra during breast cancer treatment by chemotherapy from a small animal model in longitudinal manner. Our results showed that the treatment causes variations of biochemical compositions in the skin. For further validation, the Raman spectra will have to be collected from more populations and spectra will need to be compared with immunohistochemistry of the breast tissue.

scholarly journals Autofluorescence and diffuse reflectance spectroscopy of oral epithelial tissue using a depth-sensitive fiber-optic probe

2008 ◽  
Vol 47 (6) ◽  
pp. 825 ◽  
Author(s):  
Richard A. Schwarz ◽  
Wen Gao ◽  
Dania Daye ◽  
Michelle D. Williams ◽  
Rebecca Richards-Kortum ◽  
...  
Keyword(s):  
Diffuse Reflectance ◽  
Fiber Optic ◽  
Diffuse Reflectance Spectroscopy ◽  
Reflectance Spectroscopy ◽  
Epithelial Tissue ◽  
Fiber Optic Probe ◽  
Optic Probe ◽  
Oral Epithelial

Rugged Fiber-Optic Raman Probe for Process Monitoring Applications

2001 ◽  
Vol 55 (10) ◽  
pp. 1337-1340 ◽  
Author(s):  
Pentti Niemelä ◽  
Janne Suhonen
Keyword(s):  
Fiber Optic ◽  
Signal To Noise Ratio ◽  
Notch Filter ◽  
Laser Line ◽  
Fiber Optic Probe ◽  
Monitoring Applications ◽  
Optic Probe ◽  
Holographic Notch Filter ◽  
Filter Thickness ◽  
Raman Probe

We report on the development of a simple, rugged fiber-optic probe for process Raman measurements, in which laser line rejection is based on an absorptive longpass filter made from a direct bandgap CdTe semiconductor. The probe can be used with a fixed wavelength laser at 830 nm, and Raman spectra can be recorded down to 200 cm−1 from the laser line. The filter thickness can be adjusted for final turning of the filter edge, as the edge slope is almost independent of thickness in the range 0.1 to 1 mm. Other properties of the probe, such as its signal-to-noise ratio and signal-to-background ratio, are shown to compare well with those of a state-of-the-art probe based on holographic notch filter techniques.

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