GreenTD (Dichlorobenzyl derivative, MW 362.17) is a new dichlorobenzyl derivative algaecide. It is effective and selective against harmful algal blooms (HABs). HABs cause serious problems for public health and fishery industries. Algae that cause HABs include Microcystis spp., Anabaena spp., and Aphanizomenon spp. Blooms of toxin-producing Microcystis aeruginosa occur regularly in fresh water where is rich in nitrogen and phosphorus nutrients. Environmental fate studies are needed to investigate the degradation of GreenTD. In the present study, we studied the persistence of GreenTD (90% aqueous solution) in water and toxic effects GreenTD on M. aeruginosa and reduction of microcystin production in the culture media. GreenTD was added in the water pots and microcystis media tubes at levels of 25 g/0.1 ha (0.5 mg/kg) and 50 g/0.1 ha (1.0 mg/kg). Samples were collected after 1, 3, 5, 7 and 14 days. The residues of GreenTD and microcystins in water and the media were determined using high performance liquid chromatography-diode array detection and ultra-performance liquid chromatography-tandem mass spectrometry, respectively. The half-life of GreenTD at concentrations of 0.5 and 1.0 mg/kg was 4.5 and 3.6 days, respectively. This result presents a safety level suitable for the acceptable guideline of water residue. The average recoveries of microcystins RR, YR, LR, and LA were 106–115%, 103–110%, 96–105% and 89–113% in the microcystis media, respectively. The limit of detection of (LOD) the microcystins was 0.1 µg/kg. No microcystins in the media were detected at the LOD (0.1 µg/kg). GreenTD at concentrations of 0.2 and 0.5 µg/kg had a 100% of control efficacy of M. aeruginosa. No growth of the blue-green algae was observed after 14 days of GreenTD application.

中文翻译：

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除藻剂GreenTD的实验室研究：稳定性，除藻活性和减少微囊藻毒素的产生

GreenTD（二氯苄基衍生物，MW 362.17）是一种新的二氯苄基衍生物除藻剂。它对有害藻华（HABs）有效且具有选择性。HAB对公共卫生和渔业行业造成严重问题。引起HAB的藻类包括微囊藻，鱼腥藻和Aphanizomenon藻。产生毒素的铜绿微囊藻在大量富含氮和磷营养素的淡水中定期开花。需要进行环境归宿研究以调查GreenTD的降解。在本研究中，我们研究了GreenTD（90％水溶液）在水中的持久性以及GreenTD对铜绿假单胞菌的毒性作用以及培养基中微囊藻毒素产量的降低。将GreenTD以25 g / 0.1 ha（0.5 mg / kg）和50 g / 0.1 ha（1.0 mg / kg）的水平添加到水罐和微囊藻培养基管中。在1、3、5、7和14天后收集样品。分别使用高效液相色谱-二极管阵列检测和超高效液相色谱-串联质谱法测定水和培养基中GreenTD和微囊藻毒素的残留量。在浓度为0.5和1.0 mg / kg时，GreenTD的半衰期分别为4.5天和3.6天。该结果提供了适合于残留水的可接受准则的安全水平。在微囊藻培养基中，微囊藻毒素RR，YR，LR和LA的平均回收率分别为106–115％，103–110％，96–105％和89–113％。微囊藻毒素的（LOD）检出限为0.1 µg / kg。在LOD（0.1 µg / kg）下，未在培养基中检测到微囊藻毒素。浓度为0.2和0.5 µg / kg的GreenTD具有100％的铜绿假单胞菌防治效果。