【摘要】 为探究太湖梅梁湾水体及沉积物中微囊藻毒素(MC-LR、MC-RR、MC-YR)含量的垂向分布特征,于2018年5月采集梅梁湾6个点位表层水、上覆水、混合水、间隙水以及柱状沉积物样品,并采用超高效液相色谱-串联质谱法分析样品中微囊藻毒素的含量.分析结果表明:水体中(表层水、上覆水、混合水以及间隙水) MC-LR、MC-RR、MC-YR的浓度范围分别为11.80～1297.14、2.50～818.40、1.80～176.00 ng/L,表层水、上覆水以及混合水中MC-LR的浓度高于MC-RR和MCYR,MC-RR和MC-YR之间差别较小,而间隙水中MCs三种异构体浓度大小顺序为:MC-LR>MC-RR>MC-YR;垂向分布上,间隙水中MCs异构体(MC-LR、MC-RR、MC-YR)浓度均远高于表层水、上覆水以及混合水,表层水MCs异构体浓度略高于上覆水,混合水MCs异构体浓度介于表层水和上覆水之间.对沉积物的研究发现,1～10 cm表层沉积物中MC-LR、MC-RR、MC-YR含量范围分别为0.60～26.95、0～0.90、0～8.10 ng/g,且1～10 cm层中MCs三种异构体平均含量大小顺序为:MC-LR>MC-YR>MC-RR,其中MC-LR、MC-RR、MC-YR的检出率分别为100%、70%、92%;垂向分布上,MC-RR含量较低且变化不大,而MC-YR和MC-LR含量均随沉积物深度的增加先升高后降低.相关性分析结果表明,表层水和混合水中MCs与总磷浓度呈显著正相关,而与总氮浓度无显著相关性;上覆水、间隙水以及沉积物中MCs与总氮、总磷浓度均呈显著正相关.更多还原

【Abstract】 In order to explore the vertical distribution characteristics of microcystin( MC-LR,MC-RR,MC-YR) concentration in the water body and sediment of Meiliang Bay,surface water,overlying water,mixed water,interstitial water and columnar sediment samples at six points were collected in May 2018,and the microcystin concentrations were analyzed by ultra-high performance liquid chromatography-tandem mass spectrometry( UPLC-MS/MS). The results indicated that the MC-LR,MC-RR,MC-YR concentrations in water( surface water,overlying water,mixed water and interstitial water) ranged from 11. 80-1297. 14,2. 50-818.40,1.80-176.00 ng/L,respectively. The MC-LR concentration in surface water,overlying water and mixed water were higher than MC-RR and MC-YR concentrations,but there were no significant difference between MC-RR and MC-YR concentration. The order of MC concentrations isomer in interstitial water was: MC-LR > MC-RR > MC-YR. The MC concentrations isomer( MC-LR,MC-RR,MC-YR) in interstitial water were all far higher than those in surface water,overlying water and mixed water in vertical profiles of water,the MC isomer concentrations in surface water were slightly higher than those in overlying water. The MC isomer concentrations in mixed water were between surface water and overlying water. The MC-LR,MC-RR and MC-YR contents in sediment with a depth of 10 cm ranged from 0.60-26.95,0-0.90 and 0-8.10 ng/g,respectively,and the order of the average content of three MC isomers in the 1-10 cm layer was MC-LR > MC-YR > MC-RR. The detection rates of MC-LR,MC-RR and MC-YR were 100%,70% and 92%,respectively. In the vertical distribution of sediment,the MC-RR concentration was low and showed little change,the overall trend of MC-YR and MC-LR contents increased first and then decreased with the increasing of the sediment depth. The results of correlation analysis indicated that MC isomer concentrations in surface water and mixed water were positively correlated with total phosphorus( TP) concentration,respectively,but did not show correlation with total nitrogen( TN)concentration. The MC concentrations in overlying water,interstitial water and sediment were positively correlated with TN and TP concentrations,respectively.更多还原