Getting samples
- Pre-measure tube weights (A)
- Harvest tissues and place in tubes
- Weigh tubes again (B)
- Tissue weight = (B) - (A)
- Transfer tubes in dry ice; keep frozen in -20 C
Making Samples ready
- Thaw tissue (-20 C) overnight in 4 C.
- Add 1ml of nitric acid
- Place parafilm over top; poke 1-2 holes
- Heat samples @ 90 C for 2 hrs
- Add 7 ml of MillQ water to each tube
- Use 0.2um syringe filter - filter back into tube
- Number all tubes clearly
- Cover tubes; store @ 4 C
Making ICP standards
Purchased Standard (Sigma # 74128) = 1000 ppm
Blank
(70%) x = (8.75%)(100 ml) x = 12.5
Add 100 ml Nitric acid to 700 ml MilliQ water = 800 ml total
1 ppm HIGH
(1000 ppm)(x) = (1 ppm)(250 ml)(x) = 250 ul
Add 250 uL of standard to 250 ml of blank
5 ppm HIGH
(1000 ppm)(x) = (5 ppm)(250 ml)(x) = 1.25 ml
Add 1.25 ml of standard to 249.75 ml blank
0.5 ppm QC
(1000 ppm)(x) = (0.5 ppm)(100 ml)(x) = 50 ul
Add 50 ul of standard to 100 ml blank
2.5 ppm QC
(1000 ppm)(x) = (2.5 ppm)(100 ml)(x) = 250 ul
Add 250 ul of standard to 100 ml blank
Clean all autoclaved bottles with diluted acid.
