It is a headache to encounter samples with very low liquid level during sampling, especially when automatic sampling is likely to cause too little or no sample intake. There are several ways we can improve this problem without increasing the sample size.

  1. Select the right Insert

The cost of the insert is low, and there is no high requirement for the cleanliness of the vials, which improves the reuse rate of the vial and reduces the cost of the sample vials.

There are three types of common insert: flat bottom insert, conical base with polyspring insert, and conical base insert as shown below.

  • The flat bottom insert has a large dead volume at the bottom and a low liquid level, but its cost is low;
  • The bottom dead volume of the Conical base insert is small, the liquid level is high, and the cost is more expensive than that of the flat bottom;
  • The liquid level of the Conical base with polyspring is very high. The biggest function of the polyspring is to stabilize the insert to make the sampling more smoothly. An insert with polyspring can effectively solve this problem.

Although the insert has a good cost advantage, if it is not convenient to use, we have another option for you.

2. Welded vials with inserts

This product is an integrated structure of the inset and the sample vials, the outer shell of 9-425, and the insert is welded inside.

This kind of vial has the function of internal insert when using, and solves the difficult problem of using insert. However, its cost is higher than replacing a separate insert and has certain limitations.

3. High recovery vials

As the name implies, the high recovery sample bottle is characterized by high sample recovery rate. Although its main function is to recover the sample, the special structure in the bottle also makes the sample have a high liquid level, just like the product below.

However, this product will also have corresponding disadvantages. The special specification structure makes its cost much higher than that of ordinary sample vials; The dead volume space at the bottom is difficult to clean. Although we do not encourage cleaning the sample bottle, it is inevitable to consider reusing this high-value product rather than abandoning it directly.


In addition, there are full recovery vials with smaller theoretical dead volume space, which have stronger structural performance and higher cost than high recovery vials.

The above three types of products are the solutions recommended by Welch for you when there are few samples. You can choose according to your own experimental conditions and needs. Our product number is as follows:

P/NSpecifications
00821-709139mm Transparent High recovery 30 μL screw head sample vials, primary hydrolyzed glass, 100/box
00821-70935 9mm Amber High recovery 30 μL screw head sample vials, primary hydrolyzed glass, 100/box
DD11716*29mm Micro insert, Conical bottom with polyspring, 100 pcs/box
DD1172 6*31mm Micro insert, Conical bottom, 100 pcs/box
DD1173 6*31mm Micro insert, flat bottom, 100 pcs/box
DB11270.2mL Transparent Screw headspace vials without Scale, welded conical bottom insert, 100/box
DB1128 0.2mL Amber Screw headspace vials without Scale, welded conical bottom insert, 100/box

If you have any problem or require further information, please contact info@welchmat.com.

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