Thermo Fisher Scientific
You probably already use a vial from a good brand, perhaps even a silanizied vial. However, can you be sure you are not losing any compounds when you are working with trace concentrations, especially when your samples are in the vial for a long time in your autosampler queue? Be confident that your quantification is accurate.
Todays vials in Europe are normally made of 1st hydrolytic class glass, according to all the different Pharmacopeias. But there are differences in the glass qualities meeting the Pharmacopeia requirement! A European 51 type glass is in specs, but for polar compounds, in ultra traces, the adsorption can be significant, up to 75% AND the value may vary from lot to llot or even from vial to vial! Are you willing to accept that?
If not: Thermo Scientific Chromacol GOLD GRADE vials are the solution. These vials meet every Pharmacopeia's requirements and provide a significantly better low adsorption surface compared to all standard vials on the market with no surface treatment.
Visit Chromacol GOLD-Grade inert vials web page ›
The Headspace technique requires temperature and pressure stable vials and closures. The closure needs to provide four important features:
The last two points are a challenge for many septa, as points 1 to 3 usually are fulfilled by septa with a thickness of 2-3 mm. But for point 4 there can be multiple issues due to the needle bending or breaking. Using a thinner septum deals with point 2 as a thin septum does not provide enough compression on the glass crimp border to be tight and stable enough at elevated temperatures.
The new Thermo Scientific Chromacol STME septa with large thinned penetration for crimp and screw thread caps meet all 4 points perfectly!
Visit Headspace closures web page ›
High quality polypropylene microplates coated with 200nm thick layer of silicone dioxide (glass). Plate+ provides microplates with a chemical resistance similar to glass while retaining the advantages of polypropylene. Eliminates the need to use glass limited volume inserts. Excellent for applications where plastic microplates are not applicable. Plate+ is chemically and thermally resistant and will tolerate temperatures from -80°C to +80°C. Lightweight, precision molded, cost-effective alternative to solid glass plates.
Plastic plates adsorb polar substances such as norbuprenorphine, which leads into a recovery rate which is only 80%! Glass covered plates do not interact with polar analytes which leads into a recovery rate of 102%.
For polar analytes it is recommended to use glass covered plates to avoid interactions with the surface. Furthermore glass coated plates are more inert towards organic solvents, therefore they are the better choice for HPLC and GC applications where a higher grade of organic solvents are required.