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Development Of Novel Instrument And Method For In Situ Photometric Analysis

Posted on:2014-12-03Degree:MasterType:Thesis
Country:ChinaCandidate:Y B AnFull Text:PDF
GTID:2251330392972795Subject:Analytical Chemistry
Abstract/Summary:PDF Full Text Request
In recent years, the structure of spectrometers have undergone tremendous changes.With the development and maturity of the CCD array detector technology, fiber-optictechnology and the grating technology, formating the structural style of light source,spectrographic unit and sampling unit separated from each other, the structure ofspectrometer is more flexible. Compared with traditional spectroscopic techniques,the new spectrometer has many new applications and technical features for itshigh-precision structure. And the new spectrometer will be more suitable for thediversity of space form in many fields and the variability of the production conditions.Therefore, this modern spectroscopic technique is usually called as field spectroscopy.The field spectroscopic has been widely used in chemical, pharmaceutical, lightindustry, semiconductor and other industrial sectors process monitoring, chemicalanalysis, colour and illumination control, environmental protection,anti-counterfeiting, safety assurance, military and so on. In this contribution, a varietyof on-site spectral analysis methods were established based on the self-developedfiber optic spectrometer and milk analyzer, and field methods for colour analysis andfood quality identification were developed. The main contents are as follows:1. On the basis of the commercial721-Spectrophotometer, using fiber instead of thetraditional absorption cell, fiber optic spectrometer with new optical path wasdeveloped. Under the optimized condition, analytes on the sample (paper, fruit, etc.)surface can be directly detected using fiber optic spectrometer with high stability.When we measured the extinction signals of different Nanfengmiju using theimproved instrument, significant differences of the signal could be observedaccording to different levels of Nanfengmiju, suggesting that the developed fiber opticspectrometer has the potential applications to non-invasive, on-site and quicklydistinguish the grade of Nanfengmiju and provides a new idea and method fornon-destructive, on-site and fast classification of other fruits and vegetables.2. The developed of milk analyzer and the internet of things technology-based foodsafety inspection and monitoring technology. In order to fulfill the on-site analysis ofmilk samples with minimal sample pretreatment, three fittings were modifiedaccording to the specificity of milk samples: LED as light source; new absorption cell with vertical light path as absorption cell; a detector sensor which can directlyconverse the optical signal to frequency digital signal as detector. All of these willsupport the field method for milk analysis without any sample pretreatment. Moreover,the milk analyzer can be seamlessly connected with the internet of things technology,and be applied to the monitoring of food safety. The database of milk will bedeveloped by technical supervision departments firstly. By contrasting experimentaldata which customers obtained from online detection and database, the grade of milkquality can be distinguished rapidly.3. Milk quality analysis using milk analyzer. Milk adulteration analysis and thedistinguish of brand identification was studied by milk analyzer. The result showedthat different adulterants could be quickly distinguished without any samplepretreatment. Moreover, the new field methods could be used to distinguish pure milkwith different brands.
Keywords/Search Tags:on-site, spectral analysis, 721-Spectrophotometer, Milk analyzer, quickly analysis, milk
PDF Full Text Request
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