I need to prepare a solution with Silver Thiosulphate.

So far it fails, and the solution has black particles in it.

Can anyone provide me with some practical guidelines to make this work?

I tried this;

Dedicated to a Better Way of Life through Plants TMPhytoTechnology Laboratories, Inc.Product Information SheetPhytoTechnology Laboratories, Inc. P.O. Box 13481; Shawnee Mission, KS 66282-3481 Phone: 1-888-749-8682 or 913-341-5343; Fax: 1-888-449-8682 or 913-341-5442 PREPARATION OF SILVER THIOSULFATE (STS) SOLUTION Silver Thiosulfate (STS) is commonly used to block the action of ethylene in plant cell cultures. Ethylene is a hormone that is present in the gaseous state. Ethylene increases during senescence and ripening, and has been shown to increase in plant cell cultures due to wounding or the presence of auxins. Silver nitrate may be used alone to block the action of ethylene but it is not transported as well as STS thus is seldom used alone. Prepare a 0.1 M Sodium Thiosulfate (STS) stock solution by dissolving 1.58 g of Sodium Thiosulfate (Product No. S 620) into 100 ml of water. Prepare a 0.1 M Silver Nitrate stock solution by dissolving 1.7 g of Silver Nitrate (Product No. S 169) into 100 ml of water. Store the stock solution in the dark until needed to prepare the STS. The STS solution is prepared with a molar ratio between silver and thiosulfate of 1:4, respectively. Nearly all of the silver present in the solution is in the form of [Ag (S2O3)2]3-, the active complex for ethylene effect inhibition. Prepare a 0.02 M STS by slowly pouring 20 ml of 0.1 M silver nitrate stock solution into 80 ml of 0.1 M sodium thiosulfate stock solution. The STS can be stored in the refrigerator for up to a month. However, preparation of the STS just prior to use is recommended.

My thoughts and questions;

Could I use a bigger volume of water, to deteriate the solutions of Silvernitrate and sodium thiosulphate, to have avoid precipiation?

Would it be possible, by evaportation to condentrate the final solution with Silver thiosulphate?

I am not much of a chemist so i hope these are basic questions, to be solved with rather simple solutions.

Best regards Joost.