Preparing TNP-ATP is a one-step synthesis that is relatively safe and easy. Adenosine’s ribose moiety can be trinitrophenylated by 2,4,6-trinitrobenzene-1-sulfonate (TNBS). The resulting compound assumes a bright orange color and has visible absorption characteristics, as is characteristic of a Meiseinheimer spiro complex compound linking.
To see the exact method of preparion, please refer to T. Hiratsukas and K. Uchidas paper "Preparation and Properties of 2(r 3)-O(2,4,6-trinitrophenyl) Adenosine 5-triphosphate, an Analog of Adenosine Triphosphate,"'  found in the reference section.
To revert TNP-ATP back to its constituent parts, or in other words to hydrolyze TNP-ATP to give equilmolar amounts of picric acid (TNP) and ATP, TNP-ATP should be treated with 1 M HCl at 100 degrees Celsius for 1.5 hours. This is because if TNP-ATP is acidified under mild conditions, it results in the opening of the dioxolane ring attached to the 2’-oxygen, leaving a 3’O-TNP derivative as the only product.