Irgarol 1051 and diuron are photosystem II inhibitors in agricultural activities and antifouling paints in the shipping sector. This study focused on three major ports (western, southern, and eastern) surrounding Peninsular Malaysia to construct the distribution of both biocides on the basis of the seasonal and geographical changes. Surface seawater samples were collected from November 2011 to April 2012 and pretreated using the solid-phase extraction technique followed by quantification with GC-MS and LC-MS-MS for Irgarol 1051 and diuron, respectively. Generally, the distribution of Irgarol 1051 was lowest during November 2011 and highest during April 2012, and similar patterns were observed at all ports, whereas the distribution of diuron was rather vague. The increasing pattern of Irgarol 1051 from time to time is probably related to its accumulation in the seawater as a result of its half-life and consistent utilization. On the basis of the discriminant analysis, the temporal distribution of Irgarol 1051 varied at Klang North Port, Klang South Port, and Pasir Gudang Port, whereas diuron was temporally varied only at Kemaman Port. Furthermore, Irgarol 1051 was spatially varied during November 2011, whereas diuron did not show any significant changes throughout all sampling periods. Ecological risk assessment exhibited a high risk for diuron and Irgarol 1051, but Irgarol 1051 should be of greater concern because of its higher risk compared to that of diuron. Thus, it is recommended that the current Malaysian guidelines and regulations of biocide application should be reevaluated and improved to protect the ecosystem, as well as to prevent ecological risks to the aquatic environment.

Irgarol 1051 和敌草隆是农业活动中的光系统 II 抑制剂和航运业的防污漆。本研究重点关注马来西亚半岛周围的三个主要港口（西部、南部和东部），以根据季节和地理变化构建两种杀菌剂的分布。2011 年 11 月至 2012 年 4 月收集地表海水样品，并使用固相萃取技术进行预处理，然后分别使用 GC-MS 和 LC-MS-MS 对 Irgarol 1051 和敌草隆进行定量。总体来看，Irgarol 1051 的分布在 2011 年 11 月最低，2012 年 4 月最高，所有港口的分布情况相似，而敌草隆的分布较为模糊。Irgarol 1051 不时增加的模式可能与其半衰期和持续利用导致其在海水中的积累有关。根据判别分析，Irgarol 1051 的时间分布在巴生北港、巴生南港和巴西古当港有变化，而敌草隆仅在金马曼港有时间变化。此外，Irgarol 1051 在 2011 年 11 月在空间上发生变化，而敌草隆在所有采样期间都没有表现出任何显着变化。生态风险评估显示敌草隆和伊尔加罗 1051 的风险较高，但伊尔加罗 1051 应受到更大关注，因为与敌草隆相比，其风险更高。因此，