A reliable and sound method for determining cyanide concentration in water matrices, OIA 1677 is a U.S. EPA-approved method for samples collected and analyzed in support of the Clean Water Act (CWA), Safe Drinking Water Act (SDWA), Resource Conservation and Recovery Act (RCRA), and CERCLA/SAR (Superfund).
There are significant benefits offered by OIA 1677 to measure Available Cyanide. Benefits include reduction in sample analysis time, no manual distillation required, lower detection limits, and high specificity (overcomes sulfide, copper, and oxidizing agent interferences prone to older methods). Merit Laboratories analyzes Available Cyanide by OIA 1677 on a variety of sample matrices, including wastewater, groundwater, surface water, and soil.
Sample pretreatment in the field is an integral step for water samples collected for Available Cyanide to remove potential interferences from sulfide. To support its clients, Merit Laboratories provides a field kit for Available Cyanide that includes sample bottles with preservatives, membrane filter, plastic powder funnel, and filter paper.
Proper sample preparation is essential for obtaining accurate available cyanide results. Because cyanide compounds can change rapidly after collection, following the correct field preparation procedure helps preserve sample integrity and ensures the laboratory can generate reliable analytical data.
The following guidance outlines the recommended field preparation procedure for available cyanide samples before shipment to the laboratory.
Why Field Preparation Matters
Available Cyanide is susceptible to chemical changes that can occur shortly after sample collection. Prompt filtration and preservation minimize analyte loss and help maintain the sample's original chemistry. Performing these preparation steps as soon as possible after collection improves data quality and reduces the potential for inaccurate results.
Equipment and Materials
Before heading to the field, verify that you have the following supplies:
Membrane filtration apparatus
Plastic powder funnel
Filter paper
125 mL amber glass bottle containing Lead Carbonate (PbCO₃)
125 mL amber glass bottle containing Lead Carbonate (PbCO₃) and Sodium Hydroxide (NaOH)
Hand vacuum pump
Reagents
The field preparation uses:
Lead Carbonate (PbCO₃)
Sodium Hydroxide (NaOH)
Sample Collection and Preservation
To maximize sample integrity:
Collect samples in 125 mL amber glass bottles.
Minimize headspace when filling the bottle.
Keep samples chilled at 4 ± 2°C immediately after collection.
Perform the preservation procedure as soon as possible following sample collection to minimize analyte loss.
Field Preparation Procedure
Follow these steps carefully:
Step 1: Filter the sample using the plastic powder funnel and filter paper into the bottle containing Lead Carbonate (PbCO₃). Fill the bottle completely to minimize headspace.
Step 2: Cap the bottle and gently swirl to thoroughly mix the sample with the Lead Carbonate.
Step 3: Remove the used filter paper and place it into the bottle containing Lead Carbonate and Sodium Hydroxide.
Step 4: Pour the sample from the Lead Carbonate bottle into the membrane filtration apparatus.
Step 5: Allow the sample to filter through the membrane filter. This may take some time to filter. You may need to apply a vacuum to the apparatus to speed up the process.
Step 6: Remove the barb hoses cap and pour into the lead carbonate/sodium hydroxide bottle.
Once complete, keep the prepared sample refrigerated at 4 ± 2°C until shipment to the laboratory.
Safety Considerations
Always wear appropriate personal protective equipment (PPE), including:
Safety glasses or goggles
Chemical-resistant gloves
Sodium Hydroxide (NaOH)
Sodium hydroxide is highly corrosive and can cause severe burns to skin and eyes. It readily absorbs moisture and carbon dioxide from the air and can react violently with acids and certain organic halogen compounds, including trichloroethylene.
Lead Carbonate (PbCO₃)
Lead carbonate is toxic if inhaled, swallowed, or absorbed through the skin. Avoid direct contact and use only in well-ventilated areas. Store and handle away from strong acids and strong oxidizing agents.
Tips for Successful Sampling
Following a few simple best practices can help ensure high-quality analytical results:
Prepare samples as soon as possible after collection.
Minimize headspace in all sample containers.
Keep samples properly chilled throughout transport.
Verify that all preservatives and reagents are present before beginning field work.
Label each sample clearly and completely.
Follow laboratory-provided sampling instructions and chain-of-custody requirements.
Questions?
Proper sample preparation is one of the most important factors in obtaining accurate available cyanide results. To make it easy and help you prepare of your sampling event, Merit Laboratories has prepared a quick reference guide for Available Cyanide Field Preparation. If you have questions about sampling and field prep, need sample containers, preservation requirements, or laboratory analysis, the Merit Laboratories technical team is always happy to help.
Merit Laboratories is one of the nation’s leading environmental testing laboratories, analyzing air, soil, wastewater, groundwater, drinking water, and other sample matrices for a diverse range of analytical parameters. Merit is designated as a Small Business Enterprise (SBE) and Woman-Owned Business Enterprise (WBE).