Abstract
When trace elements (EM) and multi vitamins (MV) are mixed into total parenteral nutrition solutions, the in-line filters sometimes become colored and blocked. We conducted an investigation to determine the causative substances and the mechanisms by which the coloring and blocking of the in-line filters occur.
We first determined the coloring substance. MV and EM were mixed into the parenteral nutrition solution, which was irradiated with ultraviolet light under different conditions. The resulting solutions were filtered and then an amino acid solution, KCL with vitamin B2 (VB2) and EM were then mixed into them, and these solutions then filtered again with and without shading. The filters used this time were then analyzed for substances they contained by X-ray analytic microscopy.
Secondly, we determined the mechanism of deposition of the substances using the sulfur-containing amino acid L-cysteine (Cys) and the radical-capturing agent hydroquinone was also used to confirm whether radicals were involved. Cys was decomposed by the photo-hypersensitization of VB2 generating sulfur radicals that reacted with copper to produce copper sulfide (CuS), which was precipitated. These observations indicate that the substance causing the coloring and blocking of the filters was CuS.
