Humidity control for the 2LabsToGo-Eco

Abstract

Background: The sustainability of the miniaturized open-source 2LabsToGo-Eco is unbeaten, given the high degree of dematerialization and low consumption of resources. However, the relative humidity of the environment can have a great influence on the normal phase separation at ambient conditions. As climatized analytical laboratories are normally not given and the portable 2LabsToGo-Eco is intended for use in a variety of settings, a novel humidity control was developed to control the layer activity and to improve the reproducibility of analyses, including planar bioassays.

Results: The 2LabsToGo-Eco inside can now be regulated from 20 % to 80 % relative humidity, regardless of the ambient humidity. The newly developed humidity control included a humidity/temperature sensor and fan control by the 2LabsToGo-Eco software and custom G-codes in the Marlin firmware. It checked the actual relative humidity and automatically started and stopped the fan to guarantee a relative humidity at the set value. The improved reproducibility via a controlled relative humidity was demonstrated for the analysis of food thickening agents, known to be susceptible to humidity influence. After methanolysis, the obtained methyl glycosides were best separated at 20 % relative humidity. The good repeatability of the analysis (4.3 % each for fructose and a coeluting methyl glycoside in pectin or fucose in xanthan) and the good reproducibility (3.3 % for rhamnose in tragacanth and 2.6 % as mean hR_F deviation) successfully proved the proper functionality of the new 2LabsToGo-Eco humidity control unit. The methyl glycoside profiles of the food thickening agents were highly comparable for different plates/days/users.

Significance: The applicability of the quantitative and automated 2LabsToGo-Eco was expanded to ensure good reproducibility for differing research environments. For global research with analytical laboratories distributed across different climate zones, reproducible analytical methods are supported by the novel humidity control. It ensures data comparability, data significance in long-term screening projects, and correct interpretation of biological responses and high-resolution mass signal assignments.

Keywords: Dematerialization; Food thickening agent; Miniaturization; Planar chromatography; Reproducibility; Sustainability.