To prepare estuarine soil samples for heavy metal analysis, air-dry them thoroughly and store in airtight containers with desiccants to maintain stability. Ensure samples are kept away from direct sunlight and heat, and label them clearly for identification during storage and transport.

For long-term storage of estuarine soil samples intended for heavy metal and geochemical analysis (ICP-MS and XRF), proper preservation is critical, especially in the absence of cold storage. I recommend the following steps:

1. Air-drying or freeze-drying (if possible): Begin by air-drying the samples in a clean, dust-free environment to prevent microbial activity and chemical changes. If freeze-drying is available, it's ideal for preserving the original composition.

2. Remove organic debris: Manually remove visible plant material or shells that may alter geochemical signatures.

3. Storage in airtight containers: Store dried samples in acid-washed, airtight polyethylene containers or zip-lock bags, clearly labeled, to avoid contamination and moisture ingress.

4. Keep in dark, dry place: Shield samples from light and humidity to minimize oxidation and further alteration.

5. Record metadata: Maintain detailed notes on sample location, depth, and environmental conditions during collection.

These steps can help retain the integrity of the samples for ICP-MS and XRF analyses even with limited lab resources.

Sun dry or oven dry your samples, grind and sieve dust from 75micron mesh size. Package 25grams of each soil sample and keep in a place with moderate temperature void of moisture. That's how to preserve your samples pending analyses.