[smirf]

Hi, I am trying to prepare standard solutions for UV vis spectrophotometer and i unclear about what concentration should the standards be. my solution to be analysed is between range of 0 to 250 ppm. so please help me to choose the concentration of standard solutions for plotting calibration graph

[Paolo M]

It has to be higher than the maximum value of the sample (250ppm)!

The points between 0 and the max value of the standard have to be on a line.