1. ICP • MAKING STANDARDS

2. NUMBER OF STANDARDS • Determine the number of standards necessary for your measurements (Blank, 100ppb, 500ppb, 1000ppb, etc)

3. BLANK • Blanks are prepared from reagent grade water with 3% trace metal grade nitric acid. • Blanks are typically prepared in 2L lots by adding 60 mL of concentrated HNO3 to 1940 mL of water (using a pre-marked bottle available in the PQ lab).

4. IV-ICPMS-71A Standard • Typically, the ICP standard used IV-ICPMS-71A, which contains of 10 ppm Ag, Al, As, B, Ba, Be, Ca, Cd, Ce, Co, Cr3, Cs, Cu, Dy, Er, Eu, Fe, Ga, Gd, Ho, K, La, Lu, Mg, Mn, Na, Nd, Ni, P, Pb, Pr, Rb, S, Se, Sm, Sr, Th, Tl, Tm, U, V, Yb, Zn. • This solution is diluted with the blank solution to prepare working ICP standards.

5. 100 ppb • Dilute the stock 100 times. • For a 200 ml sample pipette 2 ml of the ICP Stock and dilute to 200 g with the blank solution.

6. 500 ppb • Dilute the stock 500 times. • For a 200 ml sample pipette 10 ml of the ICP Stock and dilute to 200 g with the blank solution.

7. 1000 ppb • Dilute the stock 1000 times. • For a 200 ml sample pipette 20 ml of the ICP Stock and dilute to 200 g with the blank solution.

8. Hints on Preparing Solutions • All bottles must be very clean. • Use gravimetric measurements whenever possible. • Ie. Weigh solutions instead of pipetting. • Do not pipette directly out of ICP stock solutions; pour instead into a falcon tube. This avoids contamination. • Check the calibrates on pipettes when making up standards.