Get a quick overview of headspace sampling vials：bottle, septa and cap

Sample vials used for gas chromatography, headspace gas analysis are called headspace sample vials. Headspace sample vial is generally used for gas phase experiments. Although it is different in size from ordinary injection vials, its essence is similar to normal injection vials. The headspace sample vial is subdivided into 3 parts: bottle, septa and cap.

Application

GC gas chromatography for analysis of volatile organic compounds in solid and liquid samples after gasification experiments. Especially for the detection of residual organic solvents in alcohols, blood, and pharmaceutical products.

Bottle Material

1.USP TYPE 1, Grade A, 33 borosilicate glass

The most chemically inert glass, widely used in laboratories, especially in chromatographic applications. Class I glass is mainly composed of silicon and oxygen, contains trace amounts of boron and sodium, and has the lowest solubility and a linear expansion coefficient of 33.

2.USP TYPE 1, B grade, 51 borosilicate hydrochloric acid glass

It is mainly composed of silicon and oxygen, contains trace amounts of boron, contains more alkali metals than A-grade glass, but is still suitable for laboratory use, and its linear expansion coefficient is 51.

3.Silanized or deactivated glass

Borosilicate hydrochloride glass, which has been deactivated by organosilylation, has a strong hydrophobicity and inertness on the glass surface, which is suitable for pH-sensitive compounds, trace analysis and long-term sample storage.

Bottle Options

Volume. Headspace sample vials have different capacity specifications, including 6ml, 10ml, 20ml, 40ml, etc. Use a standard sample vial to ensure sufficient headspace. Usually, the reserved volume should be at least 50% of the sample volume.

Color. Like most regular vials, the color of the headspace sample bottle is also different for us to choose: transparent and brown. Some samples that need to be stored in the dark can choose the brown one.

Bottom. Different from injection vials, the bottom of headspace sample vials is divided into round-bottom and flat-bottom, round-bottom headspace sample vials are easy to put into the heating module for heating, and flat-bottom vials are easy to place.

MS® HLPC GC Sample Vials provide advantages over the standard straight glass sample vials. The flared end of the vial makes loading a liquid sample much easier since the flare helps guide the syringe needle into the vial. The flared end also makes the vial much stronger so that vials can easily be inserted and removed from the end of the probe using tweezers without breaking the glass.

Cover pad structure

Single layer: usually made of red rubber or PTFE, for single use only;

Double layer: made of two different materials, one for the barrier (usually PTFE) and the other for the seal (usually silicone rubber);

Triple layer (also known as sandwich septum): Also made of two different materials, usually silicone rubber coated on both sides with PTFE.

 Septa Selection Guidance

Cap Types

Headspace sample vials are available in 2 closure types: screw cap and crimp cap. The main difference between them is the different fitting methods. Generally, the sealing performance of the screw is slightly better than that of the crimp, and the screw is more convenient for manual operation, while the crimp is suitable for automatic mechanical operation.

20mm crimp top, 22.5mm: good sealing effect, compatibility with automatic sampling equipment, suitable for high boiling point, continuous ultra-high temperature experiments; pressure≤1000KPA, risk of tearing explosion, safety aluminum cover, aluminum cover cannot be used again.

18mm thread, 22.5mm: Crimp upgrade, reusable, special metal steel cover, magnetic attachment.

The magnetic cap can help the instrument to grasp the bottle more conveniently. The bimetal magnetic cap is composed of the upper layer of iron metal and the lower layer of aluminum metal, which not only meets the characteristics of convenient magnetic grasping, but also can use aluminum material to protect the bottle mouth and prevent Excessive force during capping will cause the product to break.

Differences between autosampler vials and headspace vials

When it comes to automatic sampling vials, you may compare it with headspace sampling vials. The sampling vial is the container for the instrumental analysis of the substance to be analyzed, and its cleanliness directly affects the analysis results.

There is an essential difference between the two, that is, the sampler that uses the bottle is different. Headspace samplers are all used in gas chromatographic analysis, and the corresponding bottles are also called headspace sample bottles. Simply put, headspace analysis is to analyze the gas present in the headspace sample bottle. The laboratory vials used for headspace analysis are called headspace vials; autosampler vials are a general term that includes headspace vials.

Membrane Solutions offers a wide variety of caps, septa and sample vials to meet most laboratory needs and purity requirements. All Membrane Solutions Headspace Vials are:

• Compatible with a wide range of HPLC, LC/MS and GC Instruments
• Pre-packed combo including 100 vials and caps for ease and convenience in ordering
• Vials and caps and septa are also available separately

Visit our website for more information and get your headspace sample vials:

https://www.membrane-solutions.com/sample_vials_supplies.htm