The invention relates to a passive collector for the membrane-controlled extraction of dissolved organic substances from water. The invention consists in that sorbent bodies (3) are placed in an extraction chamber (1) filled with a fluid (2), the wall (6) of which at least partially consists of a membrane (7).

Passive collector for extraction of dissolved organic compounds, useful for monitoring pesticides, comprises sorbent body placed inside membrane chamber

A diffusive sampling device (1) comprises a porous hollow diffusion body (3) removably held on a support body (2), an adsorbent body (4) located inside said diffusion body (3), wherein the hollow diffusion body (3) has a cylindrically shaped wall with an upper section comprising a closed upper end and a distal lower section comprising an open lower end and wherein the diffusion body (3) is held on the support body (2) by means of one or more o-rings (7) fixed to its lower section, wherein the adsorbent body (4) is kept in a predetermined place inside the upper section of the diffusion body (3) by way of an elastic means, such as a spring (6). The use of such devices as well as a method for air sampling and monitoring.

Diffusive sampling device

The system consists of a series of passive samplers (APs) which sense up to 16 air contaminants or pollutants simultaneously by a diffusion process. The APs included in the kit are designed for collecting: sulphur dioxide (SO 2 ), nitrogen dioxide (NO 2 ), ozone (O 3 ), the sum of nitrogen monoxide and dioxide (NOx), ammonia (NH 3 ), formaldehyde and acetaldehyde (HCHO and CH 3 CHO), organic acids: formic and acetic acids (HCOOH e CH 3 COOH), inorganic acids: sulfhydric, hydrochloric and nitric acids (H 2 S, HCl and HNO 3 ), and volatile organic compounds: benzene, toluene, ethylbenzene and xylenes (BTEX). The kit is formed by a rectangular polypropylene box containing cylindrical samplers with an inner diameter of 21 mm and a height of 12 mm, except for the AP for BTEX, which is 14 mm high. The APs have a movable portion that holds the means for immobilising the gas of interest in a filter impregnated with a specific reagent, with a teflon membrane and a stainless steel screen on the air inlet. In the AP for BTEX, the immobilising means is composed of activated carbon. The exposure time of the kit comprising APs can vary from three to 30 days, and yields integrated average atmospheric concentrations during this time, after chemical analysis of the immobilised species.

Kit composed of samplers for collecting air contaminants/pollutants

The invention provides a chemical detection liquid extraction tube used for extraction of a granular sample, which belongs to the field of sample extraction apparatuses for laboratories. The chemical detection liquid extraction tube comprises an outer tube and a tube cap; the tube cap is detachably and hermetically connected with a sample inlet of the outer tube; a liquid outlet of the outer tube is provided with a conical liquid outlet tube head; and the conical liquid outlet tube head is detachably and hermetically connected with a conical liquid outlet tube head cover. The chemical detection liquid extraction tube is characterized in that the tube further comprises a sieve-mesh inner tube with sieve meshes, the sieve-mesh inner tube is sleeved by the outer tube, a sample inlet of the sieve-mesh inner tube and the sample inlet of the outer tube are located at a same end, the bottom of the sieve-mesh inner tube is located at the end close to the liquid outlet of the outer tube, and the outer wall of the sieve-mesh inner tube is provided with a plurality of obliquely arranged elastic rubber bars. The chemical detection liquid extraction tube has the following beneficial effect: the problem of complicated detection work in conventional detection caused by separate implementation of extraction and filtering is overcome. With the chemical detection liquid extraction tube provided by the invention, loss and contamination of an extracting solution are reduced in the process of acquiring of a filtered extracting solution.

Chemical detection liquid extraction tube used for extraction of granular sample

A diffusive sampling device (1) for monitoring organic vapours in ambient air, of the type with desorption of the sampled species by solvent extraction, comprising a container (2) made of a chemically inert, substantially gas- and liquid-impervious material, having a closed bottom end and an open end opposed thereto and containing, at its bottom end, a layer of solid porous material (4) capable of uptaking the chemical substances to be sampled by physical or chemical adsorption, and a gas- and liquid-tight closure element (3) which may be coupled to the open end of the container (2), having an exposed portion closed by a pierceable membrane (10) suitable to allow the introduction of a hollow needle for the injection of a solvent and the withdrawal of the resulting solution. The device is particularly suitable for sampling organic vapours both in indoor and in outdoor environments, in urban, rural or industrial areas, and may be employed for the medium- and long-term evaluation of the atmospheric concentrations of pollutants.

I. Ist. sull'Inquinam. Atmosfer C.N.R. Allegrini

Papers

Diffusive sampling device for monitoring organic vapours im ambient air