0.5mm Pathlength Disposable Vials for FOSS XDS RLA

dangdk's picture

We have a FOSS XDS Rapid Liquid Analyser. It currently has a spacer suitable for 4mm pathlength disposible vials installed. However, we want to analyse aquous solutions for sugars and this pathlength is too great. We need around 0.5mm pathlength but FOSS only sell spacers suitable for 2mm pathlength disposable vials.
Has anyone found a workaround for this? For example is it possible to buy a 0.5mm pathlength vial that fits into the slot of the 4mm FOSS spacer (i.e. is mostly glass so giving a smaller pathlength.
We do not want to have to use the non-disposable 0.5mm FOSS cuvette as we will be dealing with thousands of samples.
Any help would be greatly appreciated!

hlmark's picture

Dangdk - One way you can reduce the pathlength in the cell is to insert a piece of clear, non-absorbing material in the cell. This will displace some of the sample and reduce the pathlength that the raidation passes through. For NIR use, a small plate of NIR-quality quartz should do that admirably. You will need to obtain a piece of suitable thickness to control the ppathlength. For example, if the cell is 4 mm thick and you want the pathlength to be 1 mm, then you need to insert a piece of quartz 3 mm thick.

roireboredo's picture


I am currently using some quartz vials (0,5 mm and 1 mm) for FOSS XDS-RLA  to measuse vegetable oils. I have 3D printed an adaptor that perfectly matches this cell sizes at RLA, since I had some quartz cells left  from standard UV-VIS spectrometers. Maybe if you find some disposable cells (for NIR transmission) from other suppliers and uses you can tailor your own adaptor.