How to use a total workflow sample prep approach to optimise elemental analysis

A Milestone e-book download is available from Analytix that presents a ‘total workflow’ approach to sample preparation in elemental analysis. It includes the ways to improve key aspects via optimisation of the following steps: Acid supply and quality, reagent addition, vessel handling, microwave digestion, sample filtering, and labware cleaning.

As well as key aspects, the e-book also offers practical advice for preventing workflow disruptions such as incomplete digestions or sample contamination that restrict a laboratory from meeting overall performance, costs, and safety goals. Also included are direct links to videos, technology reports, multiple webinars, and two case studies where employing the ‘total workflow’ approach has resulted in lower costs and time saving benefits plus reduced errors and contamination.

First things first, contamination sources

During preparation, samples can become contaminated by various elements from various sources including the analyst. The source of this contamination is discussed with a link to an additional e-book download ‘Think Blank’ for further information.

Addressing the lab acid supply and quality

Use of expensive ultrapure reagents is mandatory to work at trace levels. Why not make your own by purifying HF, HNO₃ and HCl acids with the Milestone Clean Chemistry systems. Low-cost, low-grade acid is automatically loaded into the distillation container where it is gently heated to just below its boiling temperature using a sub-boiling technique. High purity acid vapours rapidly condense into a collection bottle by forced air cooling.

Reagent addition with additional safety

Operator exposure to acid fumes especially with working with multiple acids is a concern for health and safety when adding acids to digestion vessels. In addition, the task takes valuable operator time that limits laboratory productivity and the ability of the chemist to accomplish other tasks.

The Milestone easyFILL acid dosing station from Analytix removes all these concerns by providing automated dosing of up to six acids (including HF) and reducing operator time to just a few seconds. For routine processes, it is possible to create a library of customised methods with the type and volume of reagents and the number of vessel positions.

Choosing an appropriate digestion process for your laboratory

Once the samples and reagents are placed in the digestion vessels there is a choice of digestion system that will determined by the sample type, weight, and sample throughput required. The Milestone platform of closed vessel digestion systems provides a solution for digestion of all sample types, weights, and numbers: The ETHOS rotor based systems can be used with capping stations to again remove the human factor to ensure reliable vessel closure. The new ultraWAVE 3 Single Reaction Chamber system can be used for mixed samples and weights along with different digestion media all in the same run. Operation is so simple that all you need to do is weigh your sample into a disposable low-cost vial, load it onto the support rack and press ‘START’, there is also no capping and uncapping procedure required.

Manual filtering made easy and fast

After digestion, in some cases a simple filtration step is required. This is achieved using the Milestone solvent extraction system that can filter 24 samples simultaneously.

Efficient cleaning for greater detection limits

At the end of any digestion it is important to clean the vessels to reduce potential contamination. There are several traditional methods ranging from simply rinsing with water, acid baths, or a microwave cleaning cycle that have disadvantages including acid exposure and lengthy procedures. The Milestone clean chemistry traceCLEAN acid steam cleaning system is automated and can be used for any digestion vessels plus ICP accessories.

For a free copy of the e-books or for more product information please visit the website.