QuEChERS-超高效液相色谱-串联质谱法快速测定黄豆芽中的6-苄基腺嘌呤

目的建立黄豆芽中的6-苄基腺嘌呤的超高效液相色谱-串联四极杆质谱测定方法。方法黄豆芽样品经乙腈超声提取后,经C18和PSA的固相分散净化后进样分析。使用SB-Aq色谱柱分离,以水-乙腈为流动相进行梯度洗脱。采用电喷雾离子化源,以多反应监测(multiple reaction monitoring)方式分别在负离子模式下进行检测。结果 6-苄基腺嘌呤的线性范围为5~200μg/kg,相关系数良好,检出限为0.5μg/kg,该方法在三个水平上添加回收率在88.1%~107%,相对标准偏差在1.4%~13.4%。结论本方法灵敏度高,操作简单高效,适合于黄豆芽中的6-苄基腺嘌呤的定量及确证分析。     

MEMBRANE BIOREACTORS AND CONSTRUCTED WETLANDS FOR TREATMENT OF RENDERING PLANT WASTEWATER

The performance of a novel industrial membrane bioreactor (MBR) comprising denitrification, nitrification and ultrafiltration for the secondary treatment of primary treated animal rendering wastewater has been compared with an experimental, low-cost and novel vertical-flow constructed wetland planted with Typha latifolia L. (Reedmace or Broad-leaved Cattail). The process wastewater followed pre-treatment by dissolved air flotation (DAF). The mean DAF effluent gave highly variable chemical oxygen demand (COD) and ammonia concentrations of 5816 (standard deviation (SD): 3005.0) and 614 (SD: 268.7) mg/l, respectively. The mean MBR effluent for COD and ammonia was 37 and 86 mg/l, respectively. The mean treatment performance of the constructed wetland for COD, ammonia and suspended solids was 205, 67 and 57 mg/l, respectively.     

SOLVING AN URBAN RIVER EROSION PROBLEM ON THE TILMORE BROOK, HAMPSHIRE (UK)

The Tlimore Brook, In Hampshire, typifies the Impact of new housing development that has taken place In phases over the past 20 years or so, on a river corridor. However, the issue is not one of flooding, because the channel itself had been straightened and deepened in historical times and had been adjusted further by down-cutting; thereby forming an over-large channel sufficient to contain flood flows. Perhaps rarely for lowland Britain, the key problem was that of erosion, threatening adjacent properties. This paper describes the nature of the erosion problem and the subsequent geomorphological design to mitigate it. A key unique feature of this project was the extent of backfilling required, over the entire length, to raise the over-deep channel bed. The project was constructed in 2003.