Figure 1.

Mass spectroscopic analysis of sterile saline flush syringes after routine use. The contents of the used syringes were concentrated by centrifugation. Matrix-assisted laser desorption ionization detected the α and β chains of hemoglobin as the ions at mass/charge (m/z) 15,126 and 15,867, respectively, in samples A (red), B (green), C (blue), and J (aqua) that were absent in the matrix alone (black). The lower limit of sensitivity with matrix-assisted laser desorption ionization is ≈0.5 erythrocytes per mL.