https://www.selleckchem.com/products/1-nm-pp1.html 8 % - 118.0 % and RSDs less than 9.5 %. The results demonstrate that the SNW-1 shows great potential for the enrichment of trace SAs in complex matrices.Buffer preparation and storage requires a significant facility footprint in large scale bioprocessing and together with the costs of supply chain management can have a substantial economic impact. In-line buffer mixing in chromatography is commonly performed by blending different buffer solutions using at least two pumps and a static or dynamic mixer. We developed a device for an in-line gradient delivery of buffering agents directly from solids to be applied for chromatographic separation processes. A solid feeding device with a screw conveyor and a hold tank for the solids was designed and a miniaturized system was 3D printed. The coefficient of variation for the precision of the solid feeding of 5 different buffering agents was below 5% even for very small solid flow rates necessary for lab-scale chromatography. Stability was demonstrated by a constant linear solid feed at a very low dosing rate of 0.05 g.min-1 over 24 hours. We demonstrated the suitability for chromatography by directly connecting the system to a standard chromatography workstation for protein chromatography. The solids were fed into a miniaturized continuously stirred tank reactor connected to an ÄKTA purification system. The performance of the in-line gradient delivery of buffering agents directly from solids was compared to conventional in-line buffer mixing. We were able to achieve highly linear gradients for elution using only one pump of a chromatographic system, generating the gradient by the direct addition of solids avoiding the necessity of additional pumps and hold tanks. By direct conditioning of buffers and the addition of solids a simple, just in time, at site preparation of buffers was possible. The design of the feeding unit for solid addition for buffer preparation is easily sca