Low-Cost 3D-Printed Reactionware for the Determination of Fatty Acid Content in Edible Oils using a Base-Catalyzed Transesterification Method in Continuous Flow

Abstract

A low-cost flow system was designed, manufactured, and tested to perform automated base-catalyzed transesterification of triacylglycerols to determine the fatty acid content in edible oils. In combination with traditional gas chromatographic analysis (GC-FID), this approach provides a semi-automated process that requires minimal manual intervention. The main flow system components, namely syringe pumps, connectors (i.e., flangeless fittings), and reactors, were manufactured using 3D-printing technology, specifically fused deposition modeling (FDM). By fine-tuning 3D-printer settings, high-quality leak-tight fittings with standard threading were manufactured in polypropylene (PP), which reduced the overall cost of the flow system significantly. Due to the enhanced reactivity in flow, lower catalyst concentrations (≤ 1.5 wt.%) were needed compared to traditional batch reactions (5 wt.%). The suitability of the automated flow method was determined by comparing results with the certified fatty acid content in sunflower seed oil from Helianthus annuus. Acceptable levels of accuracy (relative errors < 5%) and precision (RSD values ≤ 0.02%) were achieved. The mostly 3D-printed flow system was successfully used to determine the fatty acid content of sunflower and other commercial edible oils, namely avocado oil, canola oil, extra virgin olive oil, and a canola and olive oil blend. Linoleic acid (C18:2) was the major component in sunflower oil, whereas all other oils consisted mainly of oleic acid (C18:1). The fatty acid content of the edible oils was comparable to certified and literature values.

Automated silylation of flavonoids using 3D printed microfluidics prior to chromatographic analysis: system development

“…2 ) was 30 × 20 mm ( l × b ), and had a channel size of 0.8 mm (ID). It is worth noting that this does not account for the PP shrinkage (≈ 20%), which is very common in 3D printing [ 32 ]. The mixing zone with 90° angles was moved to the middle section of the device to ensure improved mixing at constricted sizes [ 36 ]; this was necessary to promote diffusional mixing in laminar flow followed by rigorous mixing as reported by Ward and Fan (2015) that chaotic/rigorous mixing enhances mixing which results in faster reactions in microfluidics [ 37 ].…”

“…The benefits of 3D printed devices include rapid prototyping, customizability, reusability, low cost, and not requiring specialized skills [ 30 , 31 ]. These can then be combined with open-source pump-based flow equipment to build a low-cost flow system [ 28 , 32 ]. Commercial flow equipment is available but expensive and specialized.…”

A 3D Printer in the Lab: Not Only a Toy

“…[94] Another field that has greatly exploited 3D printing is catalysis (Figure 4b). [95][96][97][98][99][100] 3D printers, in this case, can be used not only to make (flow)reactors, mixers, [101,102] multi-material parts, [103] and so on, but also to embed catalysts directly in the 3D printed material. [104][105][106][107] FDM 3D printing has also been used in optics to make diffuse optics [96,97] and optic faceplates.…”

“…Another field that has greatly exploited 3D printing is catalysis (Figure 4b). [ 95–100 ] 3D printers, in this case, can be used not only to make (flow)reactors, mixers, [ 101,102 ] multi‐material parts, [ 103 ] and so on, but also to embed catalysts directly in the 3D printed material. [ 104–107 ]…”