RESUMO
A sensitive and rapid method using liquid chromatography-hydride generation atomic fluorescence spectrometry (HPLC-HG-AFS) was developed for the simultaneous determination of seven arsenic species As3+, As5+,MMA, DMA, p-ASA, 4-OH and ROX in feeds. The isolation of the analytes from feed samples was accomplished using methanol water (1:1, V/V). The target compounds were separated on a PRP-X100 anion exchange column and then analyzed by HG-AFS. The mobile phase was 15 mmol/L (NH4)2HPO4and 10 mmol/L potassium acid phthalate. Good linearity was obtained for all of the seven arsenic species, with linear coefficients higher than 0.9964. The LODs of the seven arsenic species were between 5 and 30 μg/kg. Average recoveries for the seven analytes were in the ranges of 76.3%-108.1%, with intra- and inter-day repeatability lower than 7.7% and 17.4%,respectively. This validated method was successively applied to the determination of arsenic species in feed. This method was sensitive,simple,cheap and low operation cost,and could be used for the determination of the arsenicspecies in feeds.
RESUMO
OBJECTIVE@#To establish a liver metastasis model of nude mice in colon cancer so as to determine the function of NGX6.@*METHODS@#The cells of Group HT-29, pcDNA3.1(+)/HT-29, and pcDNA3.1(+)/NGX6/HT-29 were implanted into the spleen of nude mice, respectively. Everyday we measured the weight of the nude mice and observed their ingestion, movement and mental status. The nude mice were killed after 45 days, and the effect of NGX6 on the malignant behavior of HT-29 was assessed by this experiment.@*RESULTS@#In contrast to the other two groups, the metastasis in the liver and xenograft tumor in the spleen of pcDNA3.1(+)/NGX6/HT-29 group was significantly reduced (P<0.01).@*CONCLUSION@#The metastasis of HT-29 colon cancer cell line was significantly inhibited by NGX6 gene. This model of liver metastasis in the nude mice is a proper model to determine the anti-metastasis mechanism of NGX6 gene.