icp-oes optima 8300 measurement problem

1 post / 0 new
ST-CE
ST-CE's picture
icp-oes optima 8300 measurement problem

I prepared an intermediate reference solution using the 1000 ppm standard stock solution according to : Al 25 mL (1000 ppm) ,Cu 2.5 mL(1000 ppm) , Zn 2.5 mL(1000 ppm)added 12,5 mL HNO3 65 % and diluted to 250 mL with purified water.Using the intermediate reference solution I prepared 4 reference solutions for the calibration curve. Added 1 mL, 2.5 mL, 5 mL and 15 mL into four 50 mL volumetric flasks together with 2.5 mL of 65 % nitric acid and diluted to the mark with purified water. When I started measurements for plotting the calibration curve this message appeared for Al and Cu at some wavelengths and for Zn at all wavelengths. Standard intensity and concentration values are not in the same order. I must say that it is not the first time I perform this analysis . I obtained good results at previous determinations with the same method.[