bids are invited for ec broth (escherichia coli broth, a specialized, selective culture medium used in microbiology, 500g , sodium chloride crm, ( sodium chloride, certified reference material as per iso 17034) , 45g , nitrite standard solution crm, 1000mg/l(, as per iso 17034) , 500ml , nitrate isa (ionic strength adjuster) , 500ml , nitrate electrode inner filling solution, 60ml , supra pure nitric acid, 1000ml , nitrate electrode sensor for nitrate combination electrode 9707bnwp; (1 nos. ) , ethanol, anhydrous, ar grade, 500ml , potassium antimony tartrate hemihydrate, 50g , ammonia ph adjusting (isa) buffer solution(orion 951211) , 500ml , ammonia ion selective electrode (orion 9512hpbnwp) , (1 nos. ) , potassium chloride crm, (as per iso 17034) , 45g , phosphate standard solution, crm, 1000 mg/l, 500ml , mercury standard solution, crm, (as per iso 17034, 1000 ppm, ) , 100ml