Development of Portable Raman Spectrometer and Its Application for Determination of Melamine
A portable Raman spectrometer for melamine analysis was developed.The limit of quantitation was raised to 0.5 mg/kg by using surface-enhanced Raman scattering(SERS) technique.Using the relative measurement method,the instability of measurement was effectively improved.Experiments with raw milk,pasteurized milk,yoghourt,milk powder demonstrated that melamine concentration gradient showed good linearity with the spectrometer measured signal.The rapid inspection spectrometer had a good user interface and functions of analysis such as data collection,storage,classification,evaluation of the confidence level,RSD analysis.It was especially possible to have a rapid on-site testing with it's small size,portable,simple sample preparation requirements,the average detection time of single sample 2 min and the response time of instrument 30 s.The detection sensitivity,linear relationship and stability of the spectrometer were also good even though under extreme environment such as Tibet Lhasa and Naqu area that is an altiplano higher than 4500 m.The portable Raman spectrometer was also successfully used for the rapid authentication of olive oil and rapid detection of malachite green in fish farming water and other fields.