Research Article An Environmentally Friendly Compact Microfluidic Hydrodynamic Sequential Injection System Using Curcuma putii Maknoi & Jenjitt. Extract as a Natural Reagent for Colorimetric Determination of Total Iron in Water Samples Maneerat Namjan , 1 Natcha Kaewwonglom , 2 Chonlada Dechakiatkrai Theerakarunwong , 1 Jaroon Jakmunee , 2,3 and Wanpen Khongpet 1 1 ProgramofChemistry,FacultyofScienceandTechnology,NakhonSawanRajabhatUniversity,NakhonSawan60000, Tailand 2 Laboratory for Analytical nstrumentation and Electrochemistry nnovation, Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Tailand 3 Environmental Science Research Center,and Center of Excellence for nnovation in Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Tailand Correspondence should be addressed to Wanpen Khongpet; wanpenkhongpet@gmail.com Received 23 July 2022; Revised 16 November 2022; Accepted 15 December 2022; Published 13 January 2023 Academic Editor: Leandro Wang Hantao Copyright © 2023 Maneerat Namjan et al. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Te miniaturization of analytical systems and the utilization of nontoxic natural extract from plants play signifcant roles for green analytical chemistry methodology. In this work, the microfuidic hydrodynamic sequential injection (HSI) with the LED• phototransistor colorimetric detection system has been proposed to create an ecofriendly and low•cost miniaturized analytical system for online determination of iron in water samples using Curcumaputii Maknoi & Jenjitt. extracts as high stability and good selectivity of a natural reagent. Te proposed method was designed for online solution mixing and colorimetric detection on a microfuidic platform. Te Curcumaputii Maknoi & Jenjitt. extracts and standard/samples were sequentially aspirated to fll the channel before entering the built•in fow cell. Te intensity of iron•Curcuma putii Maknoi & Jenjitt. extract complex was monitored under the optimum conditions of fow rate, sample volume, mixing zone length, and aspiration sequences, by altering the gain control of the colorimetric detector to achieve good sensitivity. Te results demonstrated a good performance of the green analytical systems. A linear calibration graph in the range of 0.5–6.0 mg L −1 was obtained with a limit of detection at an adequate level of 0.11 mg L −1 for water samples with a sample throughput of 30 h −1 . Te precise and accurate measurement results were achieved with relative standard deviations in the range of 1.61–1.72%, and percent recoveries were found in the range of 90.6–113.4. Te proposed method ofers cost•efective, easy operation over an appropriate analysis time (2min/injection) with good sensitivity and is environmentally friendly with low consumption of solutions and the use of high stability and good selectivity of nontoxic reagents. Te achieved method was demonstrated to be a good choice for routine analysis. 1. Introduction Iron is one of the most important metals in the environ• mental geochemical, industrial, and biological processes. It can be chemically combined with many other elements to form iron ores. Te natural deposits and refning of iron ores and industrial wastes are essential parameters for the exis• tence of iron in natural water such as rivers, lakes, and groundwater. Te iron level in groundwater can be increased by the dissolution of iron compounds in soils or ferrous boreholes and handpump components through leaching from home water drinking, cooking, washing, cleaning, and Hindawi Journal of Analytical Methods in Chemistry Volume 2023, Article ID 3400863, 13 pages https://doi.org/10.1155/2023/3400863