How to prepare Hutner's trace element

It will take 10 days to be completed. Prepare early. The preparation should be done in the hume hood.

1.Dissolve EDTA（acid free）in Milli Q 250ml.

Heat the solution to ~100 ºC (A)

2.Heat MilliQ 550ml to ~100℃ and add the reagents as follows in order (B)

H3 BO3           11.4g

ZnSO4・7H2O      22.0g

MnCl2・4H2O      5.06g

FeSO4・7H2O      4.99g

CoCl2・6H2O      1.61g

CuSO4・5H2O      1.57g

Mo7O24(NH4)6・4H2O 1.10g (Ammonium Molybdate)

1. Mix (A) and (B) at ~100ºC. If successful, the solution will be “creepy” blue green.

2. Cool down the solution to 80〜90℃. Adjust pH to 6.5〜6.8 with KOH. Keep the solution warmer than 70ºC.

（~83 mL of 20% KOH may be needed）

1. Add DW to make the solution 1L, then transfer the solution to 2L flask and let it cool down in room temp. (Be careful with the hot solution!)

2. After cooling down, seal the flask with a parafilm and leave it at room temperature for 10 days.

7.If the color changes from bluish green to transparent purple, SUCCESS! Filter the debris and use the supernatant as Hutner’s trace element.