[SERS spectra of Xanthomonas oryzae pv. Oryzae (Xoo) on nano silver film prepared by electrolysis method].

The nano silver film was prepared by electrolysis method using silver nitrate and polyvinyl alcohol (PVA) in deionized water as the electrolyte, with four glass slides put in the electrolyte and two silver rods dipped into the electrolyte as the anode and cathode. A direct current was applied to the rods, then the four glass slides stayed in the silver colloids. Thus the authors got the nano silver film. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were employed to detect the silver particles in the silver colloids and on the nano silver film. From the SEM we can see that the silver particles on the film formed different layers. In one layer, the distance between two particles was about 100 nm. The samples of Xanthomonas oryzae pv. Oryzae (Xoo) were 7 different kinds of bacterial blight, namely 1-YN1, 2-YN7, 3-YN11, 4-GD414, 5-SCYC6, 6-HEN11 and 7-FWJ. Because the silver particles in the colloids were aggregated on the film, there was large electromagnetic potentiation. So the SERS spectra of Xoo were perfect. The authors used the area analytical method to distinguish the different kinds of Xoo. The silver film prepared by electrolysis was cheap and active, the preparation time of the samples was short, and any normal chemistry lab can make it, which can find excellent application to detecting the Xoo in agriculture. On the other hand, this film is active on biomolecules and bioorganism, which may be a new kind of SERS fundus to explain the creation of the SERS. Further study was under way.

[Investigation of typical melamine urinary stones using infrared spectra].

A typical melamine kidney stone confirmed by some medicine expert was collected from the first people's hospital of Yunnan. The kidney stone was adequately determined by PE corporation spectra 100(with resolution of 1 cm(-1)). The stone samples for FTIR analysis were prepared using the KBr pellet technique, where 2 mg of the pretreated stone powder was mixed with 200 mg of analytical grade KBr using an agate pestle and mortar. The digital spectrum was then scanned in the mid-infrared region from 4 000 to 400 cm(-1) at room temperature. The appearing bands between 4 000 and 2 000 cm(-1) were 3 487, 3 325, 3 162 and 2 788 cm(-1), those between 1 700 and 1 000 cm(-1) were 1 694, 1 555, 1 383, 1 340, 1 189 and 1 122 cm(-1), and those between 1 000 and 400 cm(-1) were 993, 782, 748, 709, 624, 585, 565 and 476 cm(-1). It was found that the main constituent of calculi showed few comparability with cat kidney stone, which was from cats that died after consuming the contaminated food, and confirmed that these deposits were primarily composed of melamine and cyanuric acid compared to the IR spectra of calculi in literature. It was also found that the main constituent of calculi showed few comparability with popular kidney stone by comparison with the IR spectra of calculi in literature. The spectrum of calculi was 50% respectively similar with melamine and uric acid as compared with the IR spectrum. It was found that the main constituent of calculi was melamine itself and uric acid as compared with the IR spectra of calculi and melamine: (1 : 1), because the spectrum of calculi was 83. 3% similar to melamine and uric acid (1 : 1). The appearing bands of melamine and uric acid (1 : 1) between 4 000 and 2 000 cm(-1) were 3 469, 3 419, 3 333, 3 132, 3 026, 2 827 cm(-1), those between 1 700 and 1 000 cm(-1) were 1 696, 1 656, 1 555, 1 489, 1 439, 1 350, 1 311, 1 198, 1 124 and 1 028 cm(-1), and those between 1 000 and 400 cm(-1) were 993, 878, 814, 784, 745, 708, 619, 577 and 475 cm(-1).