THAI NGUYEN UNIVERSITY UNIVERSITY OF AGRICULTURE AND FORESTRY TA THI VIET NGA RAPID DETERMINATION HEXAVALENT CHROMIUM IN TAP WATER BY USING A MICROFLUIDIC DILUTION CHIP BACHELOR THESIS Study Mode : Full-time Major : Environmental Science and Management Faculty : Internatinonal Training and Development Center Batch : 2011-2015 Thai Nguyen, September, 2015. n THAI NGUYEN UNIVERSITY UNIVERSITY OF AGRICULTURE AND FORESTRY TA THI VIET NGA Topic title: RAPID DETERMINATION HEXAVALENT CHROMIUM IN TAP WATER BY USING A MICROFLUIDIC DILUTION CHIP BACHELOR THESIS Study Mode : Full-time Major : Environmental Science and Management Faculty : Internatinonal Training and Development Center Batch : 2011-2015 Superviors : Prof. Yuh-Chang Sun Ph. Nguyen Huu Tho Thai Nguyen, September, 2015.
n DOCUMENTATION PAGE WITH ABSTRACT Thai Nguyen University of Agriculture and Forestry Degree Program Bachelor of Environmental Science and Management Student name Ta Thi Viet Nga Student ID DTN 1153180061 Rapid determination Hexavalent Chromium in tap Thesis Title water by using a Microfluidic dilution chip Prof. Yuh-Chang Sun Supervisor (s) Ph. Nguyen HuuTho Abstract: This study introduces about assessing the risk of tap water containing Chromium residuals, development a microfluidic dilution chip for rapid determination of Cr 6+ without the need of time-consuming and complex sample preparation procedures. Based on the obtained result, it is good research with the other conventional methods.
Because the chemical instrumentation or analytical methods require expensive equipment and troublesome manipulation, which is not suitable for detection in house. The study described a methodology of using a model of CO2-Laser Engraver to ablation in poly(methyl methacrylate) - PMMA based on the effects of laser power and processing speed on the depth and width of microchannels. Furthermore, successfully application Hexavalent Chromium in water – Colorimetric Method which can sense Cr6+ in stock solution of tap water with (R2 =0.9809) and determination Hexavalent Chromium in tap water was confirmed with 108 % (Spike 50 ppb) and 105 % ( Spike 100 ppb) showed that both of two volumes followed a positive direction for this research. i n Microfluidic dilution chip, dilution chip, Gradients, Keywords determination Hexavalent Chromium, tap water Number of pages 46 Date of Submision September 30th, 2015 Supervisor’s Signature ii n ACKNOWLEDGEMENT This thesis has been greatly conducted from the support as well as assistance of many people whom I would sincerely like to give deep thanks here.
First of all, I would like to express sincere thanks to the school board Thai Nguyen University of Agriculture and Forestry, Faculty of International Training and Development; Advanced Education Program, thank the teachers that have imparted to me the knowledge and valuable experience during the process of learning and researching here. In the process of implementing and completing thesis, I am deeply grateful to my supervisor, Prof. Yuh-Chang Sun at Department of Biomedical Engineering and Environmental Science, National Tsing Hua University (NTHU), Taiwan who has spent a lot of time, created favorable conditions, take care, generous and enthusiastic to guide me. In addition, I would like to say thanks to Ph.
Nguyen Huu Tho for his enthusiasm in guiding and correcting my report writing. I sincerely thank Ph. Tsung-Ting Shih, an enthusiastic guider, he was the one who has had a very positive influence on me and my orientation from the beginning on suggesting and assisting me this interesting topic during implementation of the study. I would gratefully like to thank Ping-Hung Chen, I couldn't gain new research experiences and noticeably involve in a variety of fantastic work by practicing in several new scientific instruments and chemically professional devices without him.
He continued to inspire along the way as well as his enthusiastic and responsibility. iii n I also want to thank Louise, Betty, Yuting-Luo and lovely friends in NTHU, all of your presences would help my little heart experience the second home with unforgettable memories and events. I would like to express my deep gratitude and motivation to my parents, my family and my all friends for their encouragement throughout my studies. Ultimately, in the process of implementing the project, due my time and research levels are limited so this project is inevitable shortcomings.
So, I would like to receive the attention and feedback from teachers and friends to this thesis is more complete. I sincerely thank you! Thai Nguyen, September 30th, 2015. Signature of Student: Ta Thi Viet Nga iv n TABLE OF CONTENTS LIST OF FIGURES .1 LIST OF TABLES .1 LIST OF ABBRIVIATIONS. Limitations of the study.
Microfluidic dilution chip. Microfluidic dilution chip. Hexavalent Chromium in water – Colorimetric Method. Design microchannel on AutoCAD software for Engraving on PMMA sheet.
Inspection of the channel. Creating the input on chip. NanoPort connections with microfluidic dilution chip. Verify of Microfluidic dilution chip operation with Rhodamine solution.
Determination HexavalentChromium in tap water. Fabrication microchannels on PMMA by CO2-Laser Engraver. Effect of Speed and Power of CO2 laser on microchannels of chip. Verify of Microfluidic dilution chip’s Channel.
Determination Hexavalent Chromium in tap water. DISCUSSION AND CONCLUSION .44 vi n LIST OF FIGURES Figure 2. Diagram of a dilution chip sample. Schematic demonstrating the application of the formulas.
Outlet Vertical Channel. Design microchannels on AutoCAD 2004 software. The complete designing microchannels on a PMMA sheet. Measuring channel by Power Image Analysis (PIA) systems.
Schematic illustration of image’s result of SS-50 lens. Checking distance between countersink and point on the chip. Schematic illustration of all of layers is submerged by. Transplantation chip’s layers for placing into.
Temperature control in Hot air circulation oven. NanoPort connections with microfluidic dilution chip of process. Verify of Microfluidic dilution chip’s Channel operation with. Schematic diagram of the photothermal ablation process.
Microchannels in PMMA have been engraved. Effect of the laser power on depth and width. Size microchannels with the constant power 95 (%) and. Microfluidic dilution chip's channel was examined .38 1 n LIST OF TABLES Table 3.1: Items with the their Speed and Power number of percentage .2: The Speed and Power numbers of percentage of channel.1: Examination of tap water concentration .2: Determination Hexavalent Chromium in tap water .40 1 n LIST OF ABBRIVIATIONS WHO : The World Health Organization EPA : United States Environmental Protection Agency MCL : Maximum contaminant level AAS : Atomic absorption spectrometry ICP-AES : inductively coupled plasma-atomic emission spectrometry ICP-MS : Inductively coupled plasma-mass spectrometry PMMA : Poly methyl methacrylate PIA : Power Image Analysis AVG : Average SD : Standard deviation 2 n I.
Research rationale Because of Industrialization, the World in general and Vietnam in particular is focused on wastewater problems. The main cause of heavy metal pollutants are dumped into the environmental process industrial waste water and toxic waste water untreated or treatment is not satisfactory. The phenomenon of water has been contaminated heavy metals in the water basin near industrial areas, big cities and mining areas. There is a growing public concern over the potential accumulation of heavy metals in water, owing to rapid industrial development.
Like all other forms of nature, water suffers from pollution. This problem definitely is very important to human in the world. The concern over heavy metal in the water contamination stems primarily from health risks, from direct contact with the contaminated water, and vapors from the contaminants. The World Health Organization (WHO) recommends a maximum allowable concentration of hexavalent chromium in drinking water is 0.05 milligrams per liter.
In a September 2010 draft human health assessment for hexavalent chromium, EPA proposed to classify hexavalent chromium as likely to be carcinogenic to humans when ingested. Hexavalent chromium is more toxic than trivalent chromium and poses potential health risks. People who use water containing total chromium in excess of the maximum contaminant level (MCL) over many years could experience skin rashes, upset stomachs and ulcers, respiratory problems, weakened immune systems, kidney and liver damage, alteration of genetic material, lung cancer or death. Based on the above, the mount of chromium concentration in water is likely to 3 n a serious problem for plant, organisms, environment, and etc.
However, the current methods for the detection of Chromium, which is nothing more than the use of atomic absorption spectrometer (atomic absorption spectrometry, AAS), Inductively Coupled Plasma Atomic Emission Spectrometer (inductively coupled plasma-atomic emission spectrometry, ICP-AES), inductively coupled plasma mass spectrometry (Inductively coupled plasma-mass spectrometry, ICP-MS) and fluorescence assay (fluorescent analysis), these methods often require expensive and bulky equipment. Not only that, the operator must receive professional training to operate. Therefore, establish simple and fast analytical techniques for the immediate detection at home, company on tap water that will be convenient and helpful. Thus, I propose Research: “Rapid determination Hexavalent Chromium in tap water by using a Microfluidic dilution chip”.
Research’s objectives To establish the simple and fast analytical techniques for the immediate detection Chromium element in water samples at home, company. Reducing the cost and investment in studies related detecting Hexavalent Chromium in tap water. To encourage further applicability of microfluidic dilution chip device to various fields, especially in environmental studies. Research questions Why does choice Poly (Methyl Methacrylate) (PMMA) sheet makemicrofluidic dilution chip? 4 n What is the effect of laser power and processing speed on the depth and width of microchannels from Poly methyl methacrylate (PMMA) for determining their percentage for creating microfluidic dilution chip? What is effect of microfluidic dilution chip with Hexavalent Chromium in tap water? 1.
Limitations of the study Accordingly, the main purpose of study is to combine efficiently simple-tech applications into scientific study at where we firstly focused on creating or producing scientific instruments, at least simple stuffs, in order to lower cost and expense in scientific researches to accelerate the possibilities and inspirations of study. Unfortunately, besides the possibility assessment of using microfluidic dilution chip is firstly focused on putting chips into the Temperature Control, people must graft chip carefully and correct techniques. The second, there is limited study time that is short. However, it is not influence significantly to the widely using for rapid production of microfluidic dilution chip with poly methyl methacrylate when successfully conducted.
Microfluidic Microfluidics is a multidisciplinary field intersecting engineering, physics, chemistry, biochemistry, nanotechnology, and biotechnology, with practical applications to the design of systems in which small volumes of fluids will be handled and controlled, usually in the range of microliters (10-6 ) to picoliters (10-12).At least 5 n one dimension of the channel is of the order of a micrometer or tens of micrometers in order to consider it microfluidics. Generally, when researchers speak of microfluidics, they refer to man-made channels. in networks of channels with lowest dimensions from tens to hundreds micrometers. Fluid flows in natural microchannels as blood vessels or plants capillaries are mostly excluded from microfluidics.
Microfluidic dilution chip A microfluidic dilution chip is a set of micro-channels etched or molded into a material (glass, silicon or polymer such as PDMS, PMMA). The micro-channels forming the microfluidic dilution chip are connected together in order to achieve a desired function (mix, pump, redirect and/or allow chemical reactions in a cell). This network of microchannels trapped in the microfluidic dilution chip is connected to the outside by inputs and outlets pierced through the chip, as an interface between the macro and micro-world. It is through these holes that the liquids (or gas) are injected and removed from the microfluidic dilution chip (through tubing, syringe adapters or even free holes in the chip).
Microfluidic dilution chip Over the period of two decades, scientists studied the microfluidic system and expanded its application in human life. At that time, creating a large number of silicon substrate (single-crystal silicon, glass, quartz, and so on) as material production wafer.