Order Passive Diffusion Bag Samplers from ALS

PDB Options

• Standard size PDB is 24" long and 1¼" in diameter and manufactured from 4 mil, 2" wide, “lay flat”, low-density polyethylene. Seams and connections are heat-seals only.

• PDBs come pre-filled with approximately 220 mL of certified, laboratory-grade, analyte-free, deionized water. After retrieval, simply cut the top and pour water into 40 mL vials. Different sizes available with advance notice.

• If abrasion or tearing is possible due to test site conditions, use a protective polyethylene mesh cover.

ALS PDBs

ALS is a leader in passive diffusion sampler technology and has been manufacturing and distributing PDBs since 2000. Our PDBs are made from high-quality medical grade, low-density polyethylene and are heat-sealed to resist abrasion. They are also pre-filled with certified, laboratory-grade, analyte-free, deionized water.

ALS PDBs also feature patented heat-sealed seams and unique tabs for quick attachment to hanging assemblies and easy pouring upon retrieval.

PDB Pricing Table

ALS offers a variety of PDB options to meet your specific needs, including:

• Protective polyethylene mesh covers protect your PDBs from abrasion and tearing in harsh test site conditions.
• Stainless steel, non-corrosive hanging assemblies ideal for long-term repetitive monitoring.
• Diffusion resistant mylar pouches to store your PDBs for long periods of time.

Benefits of PDBs from ALS

• Simple and inexpensive
• No purging necessary
• Rugged and durable
• Pre-filled with analyte-free water
• Certified laboratory quality control

What is a PDB?

A passive diffusion bag (PDB) is a polyethylene tube or bag filled with analyte-free water. Hung in monitoring wells for periods of 14 days, or until equilibrium is complete between the contaminant in the bag and surrounding groundwater, the PDB operates by diffusion of contaminants across the polyethylene membrane. No purging necessary.

What is a PDB?

PDBs offer a number of advantages over traditional groundwater sampling methods, including:

• No purging required, which saves time and money
• Reduced risk of sample contamination
• Ability to collect samples from remote or inaccessible locations
• More representative samples of groundwater conditions

More on PDBs

Passive diffusion bags (PDBs) are a simple and effective way to collect groundwater samples for the analysis of volatile organics. PDBs work by allowing contaminants to diffuse across a semipermeable membrane from the surrounding groundwater into a bag of analyte-free water. The longer the PDB is deployed, the more representative the sample will be of the true groundwater conditions.

PDBs can be used to collect samples from a variety of different well types, including monitoring wells, production wells, and abandoned wells. PDBs are also ideal for sampling in remote or inaccessible locations.

To collect a sample using a PDB, simply deploy the PDB in the well at the desired depth and leave it in place for the recommended deployment period. After the deployment period is complete, retrieve the PDB and carefully pour the water from the bag into a sample container.

PDBs are a valuable tool for groundwater monitoring and can help to ensure that your data is accurate and reliable.