Enhancing Food Safety: Digestion of Seafood Samples with Multiwave 7000 with PDC (Pressurised Digestion Cavity) for Optimising Mercury Analysis in Seafood Samples

Introduction:

In the realm of food safety, the issue of mercury concentration in seafood looms large, demanding vigilant monitoring worldwide. The analysis of mercury poses challenges due to its volatile nature, especially in organic compounds like Methyl-Hg. Additionally, mercury’s affinity for polymer surfaces necessitates careful consideration during sample preparation to avoid losses and cross contamination, making quartz the material of choice for the digestion vessels.

This article showcases the efficacy of the Anton Paar Multiwave 7000 series for sample preparation prior to mercury analysis. The recovery rate of an exemplary standard reference material (mussel tissue) was determined.

Instrumentation:

Digestions were performed in the Multiwave 7000, utilising 55 mL quartz vials within Rack 6 [Figure 1]. Subsequent quantitative analysis was performed with a Flow Injection Mercury Systems according to EN ISO 12846, employing NaBH4 as a reductant.

Experimental:

Sample:

Mussel Tissue - NIST 2976 Standard Reference Material

Digestion Procedure:

Approximately 0.5 g of sample was weighed into 55 mL quartz vials, followed by the addition of 6 mL conc. HNO₃ (65%) and 2 mL H₂O. The sealed vials were placed into Rack 6 within a liner containing a load solution, inserted onto the Multiwave 7000 cavity and subjected to a pressurised digestion program. After cooling, the samples were transferred for analysis.

Program Settings:

• Starting pressure: 40 bar
• Cooling temperature: 80 °C
• Pressure release rate: 10 bar/min

Step 1:

30 minutes at 260°C

Step 2:

Short run duration at 260°C — approximately 15 minutes

Long run duration at 260°C — approximately 30 minutes

Results:

Digestions with Multiwave 7000 were complete resulting in a clear solution. The recoveries for the NIST Mussel Tissue reference material were very good, confirming the effectiveness of the Multiwave 7000 digestion method.

The certified reference value for NIST 2976 "Mussel Tissue" was 61 μg/kg. In the short digestion run, the average recovery rate was 98% and in the long digestion run 90%.

Conclusion:

In addition to the mussel tissue, various fish samples were successfully digested, highlighting the versatility of the applied digestion method beyond seafood samples. We are confident that this method offers a robust starting point for the digestion of meat or similar samples, the method is adaptable based on specific parameters such as sample weight, time and temperature.

The same method and accessories can be used with any microwave of the recently released Multiwave 7101/7301/7501 series from Anton Paar. [Figure 3]

Feel free to contact us for a free demo or trial or regarding any digestion challenge you may have.

To learn more about the multiwave series, click here: https://www.anton-paar.com/au-en/products/details/multiwave/

Why Anton Paar?

Drawing on over 40 years of experience in pressurised acid digestion systems, Anton Paar has developed a high-performance microwave digestion system series. The new Multiwave 7101/7301/7501 series delivers the next level of performance, working with temperatures of up to 300 °C and pressures of up to 199 bar. This ensures complete digestions of different kind of food samples, even in the same run.

With a range of accessories, consumables, and racks of up to 28 positions, sample preparation has never been easier. Furthermore, the PDC (Pressurised Digestion Cavity) revolutionises your sample preparation workflow, it allows you to digest up to 28 different samples in the same run. Up to 4g of sample can be digested in one vial. A wide selection of vials is available, from thin-walled quartz vials with low blank values to disposable borosilicate vials for routine tasks. PTFE-TFM vials are available for special applications, and sealed quartz vessels, when working with volatile analytes.

With a compact footprint, these microwave digestion systems save you bench space in the lab. The integrated water coolers of Multiwave 7301 and 7501 help you to keep your floor space free whilst saving energy and water.

Say good bye to time consuming method development, because the Anton Paar Multiwave 7101/7301/7501 series comes with a library full of ready-to-use methods. In case there is no suitable method for your sample, reach out to us! Anton Paar offers customised application / method development support at our application lab.

Anton Paar builds equipment to the highest quality standards using the best material, this puts us into the position to provide our customers with an industry-leading 3 years warranty on the Multiwave 7101/7301/7501 series.

As an Anton Paar customer, you can count on local technical support from factory trained specialists for application support and service.

Contact us for further information or book a free demo or trial!

Anton Paar Australia I Email: info.au@anton-paar.com, Tel: +61 2 8315 4400

Anton Paar New Zealand I Email: info.nz@anton-paar.com, Tel: +64 9 414 3190