To perform a test, immerse the Vacu-vials ampoule into the sample and snap off the tip (Step 1)--the correct volume of sample is automatically drawn in, filling the ampoule; a small inert gas bubble remains in the ampoule.

To facilitate mixing the sample and reagent, tilt the ampoule back and forth so the bubble travels from end to end (Step 2). In 2 minutes or less, quantify the result by placing the filled ampoule in the cell holder of an instrument set to a wavelength for optimal absorbance (Step 3).

If you use an instrument that reads absorbance, the absorbance value can be converted to concentration units with the supplied calibration equation. Direct-reading instruments are available. Vacu-vials® Kits include 30 ampoules, a zero standard, accessory solution(s) (when necessary), a sample cup, and instructions. Material Safety Data Sheets are provided in test kits.

The Vacu-vials ampoules are 13 mm in diameter with a tapered, pre-scored tip; color forming reagents are vacuum-sealed inside.