We have developed a novel method for fast determination of chromium(VI) using egg albumin(EAB) as fluorescence probe. The influence factors, including pH, reaction time, concentration of EAB, were investigated on the performance of the method and the optimum experimental conditions were determined. Under the optimum conditions, the relative fluorescence intensity of albumin was linearly proportional to Cr(VI) over a concentration range from 1.0x10-7 to 6.0x10-5 mol L-1 with a correlation coefficient of 0.9936 and a detection limit of 5.2 nmol L-1. This is a fast, simple, high selective and environment-friendly method, which has been employed to detect trace Cr(VI) in drinking water samples with satisfactory. The infrared spectral information indicated that the possible mechanism of fluorescence quenched may be the change of the secondary structures of EAB in the presence of Cr(VI).

Angelica sinensis (Oliv.) Diels (Umbelliferae) is a well-known medicinal plant mainly distributed in Gansu Province of China. Its local and global demand is significant because of its food and medicinal applications. However, the early bolting rate of Angelica sinensis (Oliv.) Diels reaches 20%-60%, which seriously affects its food and medicinal qualities. Thus, differences in gene expression between the flower bud and sprout-shoot apical meristem underwent analysis, by means of cDNA-amplified restriction fragment length polymorphism, to better understand the flowering mechanism. 64 primer sets, each of which amplified to 60 transcript-derived fragments (TDFs), were used. Among these TDFs, 26 were expressed specifically in the flower bud. After cloning and sequencing, 32 distinct sequences were obtained from these 26 TDFs, and 25 were found with homologous sequences in databases. Confirmation of differential expression of 13 sequences was obtained by semi-quantitative RT-PCR, their showing higher expression levels in flower buds. These homologous sequences encode transposable elements, pentatricopeptide repeat-containing proteins, DNA-binding transcription factors, zinc finger (B-box type) family proteins, NADP-dependent sorbitol 6-phosphate dehydrogenase (S6PDH), amongst others.