Trace element contamination of total parenteral nutrition. 2. Effect of storage duration and temperature

Background: Patients who receive home total parenteral nutrition (TPN) freq uently are supplied with solutions up to 30 days in advance of anticipated use. The purpose of this study was to determine the stability of trace elem ents relative to time and temperature conditions, in a typical adult TPN so lution stored in a usual home environment by examining variations in delive ry of intended trace elements and inadvertent trace element contamination. Methods: Trace element concentrations were determined using inductively cou pled plasma-mass spectrometry technology. The effect of the delivery appara tus, storage duration (36 hours or 30 days) after compounding, and storage temperature (4 degrees C or 20 degrees C) were examined. Results: The deliv ery apparatus contaminated the delivered TPN solution with cobalt but did n ot alter trace elements formulated into the TPN solution. Storage duration and temperature significantly decreased three (Zn, Cu, and Mn) of the six t race elements formulated into the TPN solution. Higher temperatures and lon ger duration of storage accelerated this decrease. Boron, Al, V, Ti, Pa, Sr , and CO were the trace elements that appeared as contaminants during stora ge. Boron, Al, V, and Ti contamination decreased with higher temperatures a nd longer duration of storage. Conclusions: Longer storage duration and hig her storage temperature progressively reduced the deliverable concentration s of trace elements specifically formulated into the TPN solution and also of those trace elements that were not formulated into the TPN solution but that appeared as contaminants.