Web Analytics Made Easy -

The Vacu-vials® Test Method

Instrumental Colourimetric Analysis

Snap Tip • Mix • Read

Immerse the narrow end of the Vacu-vials ampoule into the sample and gently 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, tilt the ampoule back and forth so the bubble travels from end to end (Step 2). Wait 1-2 minutes, then quantify the result by placing the filled ampoule in the cell holder of a CHEMetrics Photometer or other instrument set to wavelength for optimal absorbance (Step 3).

Why Vacu-vials?

Instrumental tests may be preferred over visual tests for certain applications: requirement for digital read, adjustment for discoloured samples (by generating zero blank) or insufficient ambient lighting. What makes CHEMetrics Vacu-vials so special?


CHEMetrics patented, self-filling ampoule simplify and speed up water testing procedures. They eliminate the potential inaccuracies associated with manual sample and reagent volume measurement in the field. There is no measuring or mixing of reagents required. The chemical reaction is contained within the ampoule so it is safer. more

Compatibility with Third Party Instrumentation

A selected range of Vacu-vials test kits are now fully compatible with the Hach DR900 Colorimeter. This is possible with the introduction of the CHEMetrics DR900 Vacu-vials Adapter, Cat. No. A-0215, and associated custom DR900 programs created by CHEMetrics that can be uploaded to the DR900.

Our entire Vacu-vials range is compatible with any spectrophotometer that accepts 13 mm diameter round sample cells and reads absorbance (see file below). Simply set your spectrophotometer to absorbance mode, select the wavelength specified in the Vacu-vials kit instructions and follow the test procedure. The absorbance reading value can be converted to concentration units (ppm) with the supplied calibration equation, or using our convenient Concentration Calculator web app. Contact us to confirm compatibility of your particular instrument.

Spectrophotometer & Photometer Compatibility List


Vacu-vials ampoules are designed for maximum simplicity and accuracy. Each glass ampoule is 13 mm in diameter, with a tapered, pre-scored tip; colour forming reagents are vacuum-sealed inside.

A Vacu-vials Test Kit includes: 30 ampoules, zero standard ampoule, accessory solution(s) (when necessary), sample cup, and instructions. Safety Data Sheets (SDSs) are available here.

Analyte Range

CHEMetrics offers a comprehensive range of instrumental colourimetric test kits for a variety of water quality analytes. Please see the Multi-Analyte Photometer page for a complete list of compatible test kits for the V-2000 and V-3000 Series Multi-Analyte Photometers.