莱州湾海域表层海水中三嗪类除草剂的分布特征

采用液相色谱串联质谱法对莱州湾海域43个站位表层海水中13种三嗪类除草剂及脱乙基阿特拉津进行了调查研究。14种物质中,阿特拉津、扑草净、扑灭津、莠灭净及脱乙基阿特拉津被检出,分析了被检出物质的水平分布特征。阿特拉津、扑草净、扑灭津、莠灭净、脱乙基阿特拉津的检出率分别为100%、97.7%、51.2%、100%和93.0%,平均浓度分别为31.3、6.49、1.57、12.4和9.14ng/L。受陆源输入和海水交换速率的影响,被检出的三嗪类除草剂呈现出湾内高于湾口、湾西部高于东部的特点;脱乙基阿特拉津和阿特拉津的分布呈现显著正相关(R=0.336,n=43,P=0.034)。各站位阿特拉津的风险熵值均小于0.01,生态风险处于可以忽略水平。

Distributions of the triazine herbicides in the surface seawater of Laizhou Bay

Many studies have been conducted to investigate the pollution status of herbicides in rivers and groundwater; however, the pollution status of seawater is still unclear. In the present study, we established an ultra performance liquid chromatography with electrospray ionization tandem mass spectrometry （MS）method to determine 13 triazine herbicides and atrazine-desethyl in seawater. Samples were collected from the surface seawater of 43 stations in Laizhou Bay, China, filtrated and purified through the HLB solid phase extraction cartridges and separated by AcquityTM UPLC HSS C18 column （2. 1 mm × 100 mm, 1.8 pure）, and then the analytes were confirmed and quantified using MS/MS system in multiple reaction modes. Only atrazine, prometryn, propazine, ametryn and atrazine＇ s metabolite atrazine-desethyl were detected, and the detection rates and average concentrations were 100% （31.3 ng/L）, 97.7% （6. 49 ng/L）, 51.2% （1.57 ng/L）, 100% （12. 4 ng/L）, and 93.0% （9. 14 ng/L） , respectively. The concentrations of the triazine herbicides in the bay were higher than those in the bay-mouth, which may be due to the different seawater exchange rates and terrigenous inputs. The concentrations in the western stations were higher than those in the eastern stations. The concentration of atrazine was significantly correlated with the concentration of atrazine-desethyl （R = 0. 336, n = 43, P = 0. 034）. The risk entropy of atrazine was less than 0. 01 in all stations, and the ecological risk can be neglected theoretically.