Passive diffusion bag samplers with improved performance

A passive diffusion bag sampler suitable for obtaining concentrations of a variety of volatile organic compounds, said passive diffusion bag sampler comprised of:

• an outer protective rigid mesh tube, wherein the rigid mesh tube is cylindrical and sealed at each end;
• an inner polyethylene bag that is cylindrical and disposed within the rigid mesh tube, wherein the inner polyethylene bag is sealed at each end and allows the passage of volatile organic compounds to diffuse through a surface of the inner polyethylene bag;
• a ring disposed inside each end of the outer protective rigid mesh tube, each ring being rigid and flush with an end of the outer protective rigid mesh tube
• a cap disposed on each end of the outer protective rigid mesh tube;
• wherein each cap is inserted inside a corresponding ring to form a tight connection, and wherein the cap is disposed inside the ring but around the outside of a corresponding end of the inner polyethylene bag and is of sufficient length to overlie said end such that insertion of the cap into the ring forms a water-tight seal over the end of the inner polyethylene bag;
• an aperture disposed through each cap, wherein the aperture extends from outside the passive diffusion bag sampler to an interior of the inner polyethylene bag;
• and
• a plug disposed in the aperture of each cap.

A method for obtaining concentrations of a variety of volatile organic compounds using a passive diffusion bag sampler, said method comprising:

• providing the passive diffusion bag sampler having an outer protective cylindrical rigid mesh tube that is sealed at each end, an inner polyethylene bag that is cylindrical and disposed within the rigid mesh tube and sealed at each end;
• a ring disposed inside each end of the outer protective rigid mesh tube, each ring being rigid and flush with a corresponding end of the outer protective rigid mesh tube, and a cap disposed on each end of the outer protective rigid mesh tube, each cap being inserted inside a corresponding ring to form a tight connection and being disposed inside the ring but around the outside of a corresponding end of the inner polyethylene bag and being of sufficient length to overlie said end such that insertion of the cap into the ring forms a water-tight seal over the end of the inner polyethylene bag;
• an aperture disposed through each cap, and a plug in each aperture;
• filling the inner polyethylene bag with purified water and sealing the inner polyethylene bag;
• disposing the passive diffusion bag sampler in the water sample;
• withdrawing the passive diffusion bag sampler after volatile organic compounds have been diffused into the inner polyethylene bag;
• cutting one plug from one of the apertures in the passive diffusion bag sampler;
• and
• pouring the water from the passive diffusion bag sampler using a first hand.

A method for obtaining concentrations of a variety of volatile organic compounds using a passive diffusion bag sampler, said method comprising:

• providing an outer protective rigid mesh tube, wherein the rigid mesh tube is cylindrical and sealed at each end, an inner polyethylene bag that is cylindrical and disposed within the rigid mesh tube, wherein the inner polyethylene bag is sealed at each end and allows the passage of volatile organic compounds to diffuse through a surface of the inner polyethylene bag, a ring disposed inside each end of the outer protective rigid mesh tube, wherein each ring is rigid and flush with an end of the outer protective rigid mesh tube, and a cap disposed on each end of the outer protective rigid mesh tube to thereby seal the outer protective rigid mesh tube and the inner polyethylene bag, wherein each cap is inserted inside a corresponding ring to form a tight connection and is disposed inside the ring but around the outside of a corresponding end of the inner polyethylene bag and is of sufficient length to overlie said end such that insertion of the cap into the ring forms a water-tight seal over the end of the inner polyethylene bag;
• providing an aperture disposed through each cap, wherein the aperture extends from outside the passive diffusion bag sampler to an interior of the inner polyethylene bag, and a non-removable plug disposed in the aperture of each cap;
• filling the inner polyethylene bag with purified water and sealing the inner polyethylene bag,
• disposing the passive diffusion bag sampler at a target location within the water to be sampled;
• withdrawing the passive diffusion bag sampler after volatile organic compounds have been diffused into the inner polyethylene bag;
• cutting one plug from one of the apertures in the passive diffusion bag sampler;
• and
• pouring the water from the passive diffusion bag sampler using a firsthand and in a non-turbulent manner.