ABSTRACT
Objective: Ammonium alum is a common counterfeit of Alumen,and the processed product of ammonium alum is a common counterfeits of calcined Alumen. This paper aims to establish a method for identifying Alumen,calcined Alumen,ammonium alum and their processed products. Method: The samples were analyzed by scanning electron microscope (SEM) and X ray diffraction (XRD) in this paper. Result: Ammonium alum and Alumen showed obvious changes in morphology after processing. Both Alumen and ammonium alum showed obvious differences in morphology at×250 and×1 000 times microscope. Alumen presented irregular fragments,clear edge corners,smooth surface,scattered irregular small particles,occasional holes and longitudinal edges. Ammonium alum presented irregular clumps,blunt edges,not obvious edges and corners,uneven surface,scattered smaller and round-like particles. The difference in morphology was not obvious at×250 times microscope between Alumen and ammonium alum processed products. While at×1 000 times,the surface of calcined Alumen was uneven with coarse particles; the surface of counterfeit calcined Alumen was flat,and the coarse particle characteristics were not obvious. XRD can be used to rapidly and accurately identify the primary phase of Alumen,calcined Alumen,ammonium alum and ammonium alum processed products:KAl(SO4)2·12H2O,NH4Al(SO4)2·12H2O,KAl(SO4)2,and NH4Al(SO4)2 respectively, with 2θ angle characteristic value of 23,12,22 and 5 respectively for XRD peak. Conclusion: SEM and XRD techniques can be used for the identification of Alumen,calcined Alumen,ammonium alum and their counterfeit products.
ABSTRACT
Objective: To provide the new quality control means for Alumen by investigating the elemental differences between calcined Alumen and its counterfeit processed products of ammonium alum, and establishing their characteristic chromatogram. Method: The contents of 22 inorganic elements both in calcined Alumen and processed products of ammonium alum were determined by means of inductively coupled plasma (ICP)-optical emission spectrometer-mass spectrometry (ICP-OES/ICP-MS),SPSS 16.0 was used for cluster analysis (CA) while SIMCA-P 13.0 with t-test and Rank-Sum test was used to identify the differential inorganic elements. In addition, the characteristic spectrum of the inorganic elements for calcined Alumen and counterfeit calcined alumen were established. Result: Calcined Alumen had highest contents of K and Al while counterfeit calcined Alumen has highest contents of Al and Fe;Cr,Sr,and Mn contents in calcined Alumen were relatively higher,while Mn,Ti,and Ga contents in processed products of ammonium alum were relatively higher. The content of K in calcined Alumen was about 205 times of that of counterfeit products. On the contrary,the average contents of Fe,Ti,Mn and Ga in counterfeit products of ammonium alum were much higher than those in calcined Alumen,33,46,38, 27 times, respectively. A total of 18 samples were clustered into two categories in CA:calcined Alumen and processed products of ammonium alum. 18 inorganic elements showed significant difference in contents(PConclusion: This method can be used for quality control of calcined Alumen.