Why does the Sample Vial and Septa Quality are so Important?

According to different factors, the Hawach sample vial can be divided into different categories.
1). Due to color, the vial can fall into: transparent, or brown (brown is mainly used to avoid light);
2). Due volume: 2ml, 10ml, 20,ml 40 ml;
3). Due diameter: 8mm, 9mm (8-425/9-425 are thread ports), 11mm is clamp/bayonet;
4). Due to the writing blank area: there is a writing blank area, there is no writing blank area;
5). Due to the glass material: USP1 borosilicate glass (more expensive than domestic glass bottles), transparent color is divided into 7.0 and 5.0, 5.0 is better, transparent glass is all USP1;
6). Due to the type of bottle mouth: thread, buckle, clamp mouth (where the clamp mouth needs the corresponding pliers to be used together).

The importance of sample vial quality
If the tolerance is not strictly controlled, the labeled size and wall weight of the autosampler sample vial may be different, which will affect the sample volume in the sample vial, especially important for a small number of samples. HAWACH’s strict tolerance control runs through the entire manufacturing process, from the initial design to the final photoelectric scanning inspection process, to ensure the accuracy of each sample vial and cap specifications.

The harm of using poor quality vials and seals on the autosampler
1. Inconsistent thickness at the bottom of the vial: Inconsistent sampling; damage to the injection tip;
2. Autosampler sequence stops: Mishandling or dropping vials; loss of precious samples
3. Seal leaks are not detected: Sample loss, and volatility; may contaminate samples
4. Displaced or misaligned septa: Sample loss; sample contamination
5. Ghost Peaks: Contamination of cap septa

The importance of septum quality
To prevent contamination and avoid damage, the correct septum selection is crucial. Here are some issues you should pay attention to:
1. Temperature control
At higher temperatures, the septa will degrade and cause sample contamination. Rubber septa are not suitable for high-temperature applications, because they are only stable below 90℃. Generally, PTFE-lined silicone rubber septa are the best choice for various temperatures.
2. Debris
When the tip diameter is too large compared to the septum or the septum material cannot withstand multiple injections, debris will be generated. At this time, the septum material will fall off into the sample vial and contaminate the sample. Here’s how to prevent debris:
a. Select a PTFE-lined septum to prevent the septum material from entering the sample;
b. Make sure the tip is not damaged;
c. Using pre-perforated septa can almost completely eliminate debris.
d. For highly sensitive samples, we recommend the use of a PTFE-lined (“sandwich”) septum, as the PTFE layer acts as a chemical-resistant barrier.
3. Resealability
Resealing is an important factor to consider when choosing a septum. Taking it in the long term, the PTFE/silicone rubber/PTFE is recommended.
4. Puncture ability
In general, silicone rubber septa are easier to puncture than red and butyl rubber septa. The pre-perforated septum is the best choice, it is the easiest to puncture and reduces the possibility of debris.
5. Cap and septum compatibility