The determination of ambient carbonyls by the derivative method inevitably leads to the introduction of extra 2,4-dinitrophenylhydrazine (2,4-DNPH) into the sample solution. Traditional solid phase extraction (SPE) materials cannot remove this interference. To address this issue, a selective molecularly imprinted solid phase extraction (MISPE) column was prepared. With 2,4-dinitroaniline (2,4-DNAN) as the dummy template, MISPE could eliminate the excessive derivative agent (2,4-DNPH) in the air samples. Consequently, the sample could be concentrated effectively while the sensitivity increased greatly. By coupling MISPE and high performance liquid chromatography (HPLC), the developed method was used to study the concentration and source of 14 carbonyls of PM2.5 during spring in Guangzhou Higher Education Mega Center. Results showed that the total concentration of carbonyls increased with the level of air pollution. Particularly, the content of isovaleraldehyde increased sharply to account for 21% of the 14 total carbonyls in the haze days. Moreover, a high positive correlation between isovaleraldehyde and propionaldehyde was found either in normal days or haze days. From the correlation analysis, it was shown that anthropogenic emissions together with photochemical reaction had contributed to the abnormally high levels of carbonyls in ambient PM2.5 in the haze days. This aspect should be further investigated.

In this study, cultivation of C412 strain was achieved using an optimized culture medium containing (per liter) 5% molasses waste water, 2. 5 g/L molasses, 1 g/L beef extract, 3 g/L (NH4)2SO4, 1 g/L NaCl, 5 g/L K2HPO4, 2 g/L KH2PO4, 0. 05 g/L MgSO4·7H2O (pH = 7). Under this condition, the OD600of C412 could reach 3. 12 after 17 h. Furthermore C412 was used to study the optimal condition for removing methylene blue, and the highest removal efficiency (97. 09% ) was achieved with following conditions: the concentration of methylene blue 25 mg/L, the OD600of the initial cell inoculation dosage 0. 18, pH 7. 6 and fermentation time 18 h. These results showed that Bacillus sp. C412 was capable of removing methylene blue efficiently and had a bright future in industrial application.

Study on the extraction and conditions of hesperidin in Pericarpium citri reticulatae under the detection of UV Absorption Spectrum.Experiment shows that hesperidin under certain conditions has a higher extraction rate and the higher purity:in the microwave irradiation,the petroleum ether-methanol-60% ethanol extraction in three steps,the third step in a 60% ethanol extract can be access to 80% of the hesperidin;UV detection under certain conditions may be to monitor and quantitative determination of hesperidin in the extract :The step-by-step,after extraction with petroleum ether and methanol and removal of interference,UV method will facilitate rapid determination of hesperidin content,the method is as:0.1% NaOH-75% ethanol is as blank and solvent,detecting under 362 nm,reference HPLC method,the results are with good accuracy;simplifying extraction process of hesperidin is as follows:extracted Pericarpium citri reticulatae three times by 95% ethanol under microwave irradiation,and then extracted the residue by 60% ethanol to get the result.