Alkaline Digestion for Cr(VI)

I'm trying to digest a sand sample in order to test the adsorption of hexavalent chromium.

I was previously using microwave digestion, using acid digestion method (1:3 HNO3:HCl).

I have afterwards read several journals that state that acid digestion is for total chromium.

Somehow they suggest alkaline digestion for digesting the sand sample for hexavalent chromium. However, this method uses a hot plate.

Is there any way to achieve alkaline digestion using microwave digestion? 

Taxonomy

• Soil
• Solid Waste Management
• Solid Waste Treatment
• Sludge Treatment
• Sludge Management
• Solid Wastes & Wastewater Recycling
• Soil & Water Assessment Tools
• Soil Management
• Soil Conservation
• Sediment Management

2 Answers

1. https://www.epa.gov/sites/production/files/2015-12/documents/3060a.pdf

   This link will give you the best solution regarding alkaline digestion, also known as Method 3060

2. Please find attached documents outlines the alkaline digestion method to solubilize both water-insoluble and water soluble hexavalent chromium[Cr(VI)] compounds from soils, sludges, sediments, and similar solid waste samples.

   https://www.epa.gov/sites/production/files/2015-12/documents/3060a.pdf