As demonstrated above, our microreactor setup allows for longtime measurements with low consumption of reactants and solvents and the reusability of our biocatalyst, making it an efficient and sustainable method. However, compared to the microreactor, using a commercially available C18-column in the online analytic setup still involves relatively high solvent consumption (600 µl•min -1 or approx. 864 ml•d -1 ). To further reduce solvent usage, we integrated a chipHPLC-setup as a modular alternative to the commercially used C18-column (Fig. A; the simplified setup is based on a joint publication ). Initially, the chipHPLC-setup was integrated, the injection principle visualised, and the duty cycle was automated similarly (detailed description in the ESI in section S3). The separation was optimized by sampling the reaction performed in batch through a syringe as sample feed. Subsequently, the chipHPLC was coupled to a packed-bed microreactor, as presented above. The achieved separation is presented in Fig. B. Herein, the chipHPLC system offered a significantly faster separation time below 2 min, leading to an increased acquisition frequency and, thus, faster real-time monitoring. In addition, such short acquisition times could be used in the future, for instance, in kinetic studies of the initial phase of a catalysed reaction. The system also demonstrated good operational stability with minimal solvent consumption down to 75 µl•min -1 or approx. 108 ml•d -1 , resulting in a reduction of >80%. The rapid analysis time with minimal consumption demonstrates this modular approach as optimal for analytical setup integration. Further information on the injection principle and conducted chipHPLC runs, including pressure data, a longterm stability test, and a detailed comparison of the different methods, can be found in the ESI in section S5.3.