Sampling Technologies

Micro-Chamber/Thermal Extractor

The Micro-Chamber/Thermal Extractor™ (µ-CTE™) is a versatile and compact unit with four small cylindrical chambers that enables the sampling of chemicals released from products or materials. Released volatile and semi-volatile organic compounds (VOCs and SVOCs) are collected onto sorbent tubes for analysis by TD–GC–MS. Applications range from emissions screening of construction materials, consumer products, and car trim to aroma or fragrance profiling.

- Designed for sampling VOCs or SVOCs emitted from products and materials.

- Humidifier and permeation accessories extend the capabilities of the instrument.

- A full range of accessories for the Micro-Chamber/Thermal Extractor is available.

Read more: Micro-Chamber brochure

ACTI-VOC PLUS

ACTI-VOC PLUS™ is a robust, fast-flow sampling pump kit designed for sampling volatile organic compounds (VOCs) onto sorbent tubes for analysis via thermal desorption (TD). With an expanded flow range compared to the ACTI-VOC series, ACTI-VOC PLUS is the ideal choice for sampling semi-volatile organic compounds (SVOCs), where required sampling flows are in the range of 300–500 mL/min.

The device allows for the sampling of precise air volumes in constant-flow mode (20–500 mL/min). Long battery life ensures stable performance for over 8 hours. The pump is programmable and allows for the recording of sample data. A dedicated carry-case protects the pump from damage during storage and transport. Users can replace the filters and battery themselves to minimize downtime during maintenance.

Read more: ACTI-VOC PLUS flyer

Pumps used for active sampling include 'grab-samplers' and battery-powered pumps. By allowing precise volumes from 20 mL to several hundred liters to be sampled into tubes, this method ensures compatibility with a wide concentration range (from sub-ppt to high ppm levels).

Active sampling can be used in combination with multi-bed sorbent tubes to collect analytes over a wide volatility range; it can also be used for collecting very volatile organic compounds - VVOCs (e.g., propene and chloromethane) through to semi-volatile organic compounds - SVOCs (e.g., dodecyl phthalate and six-ring PAHs).

MTS-32 (multiple-tube sampler)

The MTS-32 Multi-tube sequential sampler is a compact, robust, and portable sampler, designed for unattended sampling of air onto a series of sorbent tubes. Ambient air is pulled sequentially through a series of up to 32 industry-standard thermal desorption tubes by a low-flow sampling pump. Each tube is sampled at the same flow rate, so that the same volume of air is collected.

- Field-portable – the MTS-32 can be used virtually anywhere

- Labour-saving, unattended sampling – retrieve the instrument at the end of the extended sampling period

- Trusted sample integrity – tubes are sealed with diffusion-locking technology, preventing unwanted air ingress and sample loss

Read more: MTS-32 flyer

Easy-VOC

Easy-VOC is a grab sampling kit, a hand-operated pump for rapid ‘grab-sampling’ of precise volumes of air/gas directly onto sorbent tubes, for analysis by thermal desorption (TD). In contrast to canister sampling, grab-sampling onto sorbent tubes allows analytes from a wider volatility range to be sampled (in the region of C2/3 to n-C44), plus many polar and reactive species.

- Enables sampling of precise volumes of air (50 mL and 100 mL intervals)

- Portable and can be used remotely without batteries or electrical power

- No need for calibration means no additional tools are required

Read more: Easy-VOC flyer

Markes’ BioVOC-2™ breath sampler is a lightweight and simple-to-use device designed for non-invasive biological exposure monitoring of VOCs. Using a design pioneered by the UK Health & Safety Executive, BioVOC-2 collects the last 129 mL of expired breath for transfer to a sorbent tube, and subsequent analysis by thermal desorption. 

- Simple manual transfer of collected breath to industry-standard TD sorbent tube

- Non-invasive and easy to use, removing the need for medically qualified staff

- Collects the last portion of breath, largely alveolar air, which is the most reliable indicator of VOCs in the blood

- Can be used multiple times for one participant within a single sample sitting

- Disposable mouthpiece to avoid contact with the BioVOC-2 body

BioVOC-2 is for research use only. Not for use in diagnostic procedures

Read more: BioVOC-2 flyer

HiSorb probes

HiSorb™ probes are designed for use with industry-standard sorbent tubes with the TD100-xr™ or used directly in the Centri automated sample extraction platform. HiSorb probes are able to sorptively extract VOCs and SVOCs from a range of sample types, including water-based solutions, emulsions and suspensions, as well as solids with both immersive and headspace sampling.

Read more: HiSorb sorptive extraction brochure

Gas sampling bags

Gas sampling bags are a popular method of capturing whole-air samples. Like canisters, they enable the analysis of VVOCs using on-line TD systems, that cannot be quantitatively retained on sorbent tubes.

Available in Tedlar and multi-layer foil:

- Tedlar bags are suitable for general-purpose VOC sampling.

- Multi-layer foil bags are suitable for sampling thermally labile and reactive compounds, such as volatile sulfur species.

Both bag types are available in 1, 2, 5 and 10 litre capacities.

Air Sampling Canisters

Air sampling canisters are used for the collection, storage, and analysis of the most volatile organic compounds, such as C2 hydrocarbons and freons. Canisters are available in stainless steel (TO-Can) and inert-coated stainless steel (SilcoCan), in volumes ranging from 1 to 15 L. These canisters are ideal for grab-sampling to determine the time-weighted average (TWA) of ambient air.

- Equipped with a three-port RAVE valve featuring a vacuum/pressure gauge (-30" Hg/60 psi).

- Supports US EPA Methods TO-14A/15.

- Compatible with Markes’ CIA Advantage-xr system.

TF SPME

TF-SPME (thin-film solid-phase microextraction) is a novel sampling approach for ultra-trace-level analysis of VOCs and SVOCs using sorptive extraction. TF-SPME uses a carbon mesh strip impregnated with a sorptive phase with 100× greater volume than a typical SPME fiber.

- Applicable to a wide range of compound classes

- Environmentally friendly and solvent-free

- Split-flow re-collection on compatible instruments enables repeat analysis under different split conditions for analysis over a wide concentration range

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TF-SPME flyer

Thin Film SPME Instruction for use

SPME fibers

Sorptive extraction is a convenient approach for complex samples and for monitoring persistent organic pollutants in foods, beverages and other products derived from natural sources. In SPME, (solid-phase microextraction) fibers are coated with absorptive phase(s), to extract volatiles in either headspace or immersive modes.

- Compared with static headspace, SPME can offer improved selectivity and concentration capability

- A variety of sampling phases are available to extend the applicability of SPME over a range of target analytes

- SPME can be extended to SPME–trap with the Centri sample extraction and enrichment platform

Vials & caps

Markes supplies a range of vials and caps to support users undertaking headspace (HS), solid-phase micro-extraction (SPME), thin-film SPME (TF-SPME) and HiSorb sorptive extraction sampling. Vials are available in 1.5, 10 and 20 mL sizes, with crimp-tops or screw-tops. Caps to suit sampling method(s) are provided with the appropriate septum.

- Decapper and crimping tools available for use with crimp-top vials

- 5 mL vials available in clear and amber glass

- Caps for 10/20 mL vials are magnetic, to enable automated handling by the Centri robot

Read more: Sample extraction supplies catalogue