南海北部沿岸海域近江牡蛎体中的三氯杀螨醇

Dicofol in oysters(Crassostrea rivularis) from coast of northern South China Sea

在南海北部沿岸23个观测站,于2008～2010每年春季分别采集成体近江牡蛎(Crassostrea rivularis),取其软组织进行均质,有机溶剂超声萃取,浓硫酸净化,硅土/氧化铝柱层析,然后用气相色谱法测定其中三氯杀螨醇(DCF)。测定结果(10-9,湿重)显示:DCF含量在65.2%样本中低于检出限,在其余样本中为0.244～4.42,明显低于发达国家的最大残留限量和国际组织的容许摄入量。牡蛎体中DCF的区域平均含量在北部湾顶明显较高(1.41),在粤西(0.278)和海南岛(0.199)相对较低,在珠江口(0.769)高于总体平均含量(0.547),在粤东为0.466。牡蛎体DCF含量的年际变化明显,总体在2009年(0.778)明显高于2010年(0.489)和2008年(0.373),在不同区域、不同测站的年际变化大小不一。

Jinjiang oysters （ Crassostrea rivularis） were collected from 23 sites along coast of northern South China Sea. All soft tissues of thirty adult individuals were fetched as one sample at each site in every spring during 2008 -2010. The part of sample homogenate was pretreated through ultrasonic extraction with organic solvents, purification with oil of vitriol, column chromatograph with florsil and alumina, and so on. Finally dicofol in the tissues was determined by gas chromatography. The dicofol contents were 10.9 （ wet weight）, and the range was from 〈 0.1 to 4.42 with average of 0. 547, and lower than its maximum residual limit or acceptable daily intake. The regional variances of dicofol contents were observed, the oysters collected from northern Beibu Bay contained more dicofol （mean = 1.41 ）than those collected from Pearl River Estuary, East Guangdong coast, West Guangdong coast and Hainan Island, （mean = 0. 769,0. 466,0. 278 and 0. 199, respectively）. The dicofol contents also varied with time, the highest in 2009, and lowest in 2008, middle in 2010,0. 778,0. 489,0. 373, respectively.