Comparison of solid phase extraction combined with vortex assisted liquid liquid micro extraction and vortex thesis title assisted liquid liquid micro extraction with increased

THAI NGUYEN UNIVERSITY UNIVERSITY OF AGRICULTURE AND FORESTRY NGO QUI TRUNG COMPARISON OF SPE-VALLME AND VALLME WITH INCREASED SAMPLE VOLUME FOR SENSITIVITY ENHANCEMENT IN DETERMINATION OF STRONTIUM BY ION CHROMATOGRAPHY BACHELOR THESIS Study Mode : Full-Time Major : Environmental Science and Management Faculty : International Programs Office Batch : 2013 – 2017 Thai Nguyen, 20/07/2017 DOCUMENTATION PAGE WITH ABSTRACT Thai Nguyen University Of Agriculture And Forestry Degree Program: Bachelor of Environmental Science and Management Student name: Ngo Qui Trung Student ID: DTN 1253060212 Comparison of solid phase extraction combined with vortex-assisted liquid-liquid micro-extraction and vortex- Thesis Title: assisted liquid-liquid micro-extraction with increased sample volume for sensitivity enhancement in the determination of strontium by ion chromatography Assoc Prof Dr Wu, Chien-Hou - National Tsing Hua Supervisor (s): University,Taiwan Assoc Prof Dr Nguyen The Hung - Thai Nguyen University of Agriculture and Forestry, Vietnam Abstract: Strontium compound that is considered a danger to human health If it absorb to much in the body, it will make some disease such as: lung cancer or bone cancer Many methods was found by difference scientists but the sensitivity quite low Therefore, in this research, we compared solid phase extraction and large sample volume (50 mL) combined with vortex-assisted liquid–liquid micro-extraction to test the sensitivity enhancement in the determination of strontium by ion chromatography According to VALLME, dispersion of micro-volumes of a low density extraction organic solvent into the water sample is achieved by using for the first time vortex mixing Strontium from the organic phase was stripped with nitric acid back to aqueous solution and determined by ion chromatography The optimum microextraction conditions were as follows: 50 mL aqueous samples with mL 50 mM TPB; 400 μL of 1-octanol as the extraction phase with 10 mM DtBuCH18C6 followed by sequential vortex 20s and manual shaking 10s The strontium-rich organic solvent was recovered by centrifugation at 3200 rcf for The calibration curve showed good linearity over the range between 0.01 and 0.1 mg L-1 with detector sensitivity was 0.7635 and a correlation coefficient higher than 0.9992 while the LOD was 8.74 µg L-1 Moreover, when we combined vortex-assisted liquid–liquid micro-extraction with solid phase extraction at the same linearity range, the detector sensitivity was 1.0671 and the correlation coefficient R2 was 0.9861 Therefore, SPE-VALLME methodology more effective than other methods (with highest detector sensitivity) when we increased sample volume Key-words: Strontium (Sr), solid-phase extraction (SPE), ion chromatography, vortex-assisted liquid–liquid microextraction (VALLME) Number of pages: 53 Date of submission: 20th September, 2017 Supervisor’s signature ACKNOWLEDGEMENT Firstly, I would like to express the deepest appreciation to teachers in faculty of International Training and Development as well as teachers in Thai Nguyen University of Agriculture and Forestry, who have dedicated teaching to me the valuable knowledge during study time in university and gave me a chance to my thesis oversea It is with immense gratitude that I acknowledge the support and help of Biomedical Engineering & Environmental Science Department, National Tsing Hua University for accepting me to working in this wonderful place Foremost, I would like to express my sincere gratitude and deep regards to my supervisor: Assoc Prof Dr Wu, Chien-Hou of National Tsing Hua University (Taiwan), who guidance, encouragement, suggestion and very constructive criticism have contributed immensely to the evolution of my ideas during the project Without his guidance, I may not have this thesis My special thanks go to Mr.Bill (Wang Chin Yi) Ph.D student-second supervisor - who offered me a warm welcome and provided the information and data necessary for my implementation process and helped me finish this thesis I sincerely thanks to Assoc Prof Dr Nguyen The Hung for his advices, assistance, sharing experiences before and after I went to Taiwan, helping me to understand and complete proposal and thesis My sincere thanks also go to all my classmates – K45 AEP for helping me finish the study C.33.44.55.54.78.65.5.43.22.2.4 22.Tai lieu Luan 66.55.77.99 van Luan an.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.33.44.55.54.78.655.43.22.2.4.55.22 Do an.Tai lieu Luan van Luan an Do an.Tai lieu Luan van Luan an Do an Special thanks to Lam, Tar Mivongsack, members in Chien’s laboratory who hearty help me a lot of when I work in there and all the people who helped me when I stayed in Hsinchu - Taiwan Finally, I would like to thank my family, for their love and supporting me throughout my life In the process of implementing the project, I know that my thesis report got many mistakes so this report is inevitable shortcomings So, I would like to receive the attention and feedback from teachers and friends to this thesis is more complete Hsinchu, April 2017 Student Ngo Qui Trung Stt.010.Mssv.BKD002ac.email.ninhd 77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77t@edu.gmail.com.vn.bkc19134.hmu.edu.vn.Stt.010.Mssv.BKD002ac.email.ninhddtt@edu.gmail.com.vn.bkc19134.hmu.edu.vn C.33.44.55.54.78.65.5.43.22.2.4 22.Tai lieu Luan 66.55.77.99 van Luan an.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.33.44.55.54.78.655.43.22.2.4.55.22 Do an.Tai lieu Luan van Luan an Do an.Tai lieu Luan van Luan an Do an TABLE OF CONTENT LIST OF FIGURES LIST OF TABLES LIST OF ABBREVIATIONS 10 PART I INTRODUCTION 11 1.1 Research rationale 11 1.2 Objectives of this research 12 1.3 Research questions and hypothesis 13 1.4 Limitation of this research 13 PART II LITERATURE REVIEW 14 2.1 The characteristics and health effects of strontium(Sr) 14 2.1.1 Characteristics of strontium 14 2.1.2 Applications 16 2.1.3 Origins of strontium in the environment 16 2.1.4 Health effects of strontium 16 2.1.5 Effects of strontium on the environment 18 2.2 Methods to determine strontium in the environmental sample 19 2.2.1 Solid-phase extraction (SPE) 19 2.2.2 Vortex-assisted liquid-liquid microextraction (VALLME) 23 2.2.3 Combination two methods: solid-phase extraction and vortex-assisted liquid-liquid microextraction (SPE-VALLME) 26 2.3 Crown ether 28 2.4 NaTPB (Sodium tetraphenylboron) 31 PART III.METHOD 32 3.1 Material 32 3.1.1 Chemical materials 32 3.1.2 Instrumentation 32 3.2 Method 34 3.2.1 Determine the optimum concentration 34 3.2.2 Solid-phase extraction (SPE) 36 3.2.3 Vortex-assisted liquid-liquid microextraction (VALLME) 37 4.1 Analysis 38 PART IV: RESULTS 39 Stt.010.Mssv.BKD002ac.email.ninhd 77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77t@edu.gmail.com.vn.bkc19134.hmu.edu.vn.Stt.010.Mssv.BKD002ac.email.ninhddtt@edu.gmail.com.vn.bkc19134.hmu.edu.vn C.33.44.55.54.78.65.5.43.22.2.4 22.Tai lieu Luan 66.55.77.99 van Luan an.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.33.44.55.54.78.655.43.22.2.4.55.22 Do an.Tai lieu Luan van Luan an Do an.Tai lieu Luan van Luan an Do an PART V: DISCUSSION AND CONCLUSION 47 4.2 Discussion 47 4.3 Conclusion 48 REFERENCES 49 Stt.010.Mssv.BKD002ac.email.ninhd 77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77t@edu.gmail.com.vn.bkc19134.hmu.edu.vn.Stt.010.Mssv.BKD002ac.email.ninhddtt@edu.gmail.com.vn.bkc19134.hmu.edu.vn C.33.44.55.54.78.65.5.43.22.2.4 22.Tai lieu Luan 66.55.77.99 van Luan an.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.33.44.55.54.78.655.43.22.2.4.55.22 Do an.Tai lieu Luan van Luan an Do an.Tai lieu Luan van Luan an Do an LIST OF FIGURES Figure 2.1 Solid phase extraction steps 22 Figure 2.2 Structures of common crown ether: 12-crown-4, 15-crown-5, 18-crown-6, dibenzo-18-crown-6 and diaza-18-crown-6 29 Figure 3.1 Ion chromatography system diagram 34 Figure 4.1 Recovery strontium of 100ml sample volume 3M HNO3 and chromatography graph of samples 39 Figure 4.2 Recovery strontium of 100ml sample volume 8M HNO3 and chromatography graph of samples 40 Figure 4.3 Calibration curve of concentration Sr (II) at low volume sample (2ml)415 Figure 4.4 Comparison 1-octanol recovery between solution sample with crown ether, TPB and without crown ether,TPB 37 Figure 4.5 Effect of volume of extraction solvent on the extraction efficiency of strontium Extraction condition: volume 50ml, Sr (II) concentration 50µg/L, 3ml TPB 38 Figure 4.6 Calibration curve of concentration Sr (II) at high volume sample (50ml) 39 Figure 4.7 Comparison solid phase extraction combined with vortex-assisted liquidliquid microextraction and vortex-assisted liquid-liquid microextraction at low and high volume 40 Stt.010.Mssv.BKD002ac.email.ninhd 77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77t@edu.gmail.com.vn.bkc19134.hmu.edu.vn.Stt.010.Mssv.BKD002ac.email.ninhddtt@edu.gmail.com.vn.bkc19134.hmu.edu.vn C.33.44.55.54.78.65.5.43.22.2.4 22.Tai lieu Luan 66.55.77.99 van Luan an.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.33.44.55.54.78.655.43.22.2.4.55.22 Do an.Tai lieu Luan van Luan an Do an.Tai lieu Luan van Luan an Do an LIST OF TABLES Table 2.1 Physical and chemical properties of strontium (A.crawford 1790) 15 Table 2.2 Properties of 4’,4”(5”)-di-tert-butyldicyclohexano 18-crown-6 30 Table 2.3 Properties of sodium tetraphenylboron (NaTPB) 31 Table 4.1 Comparison recoveries 1-octanol with and without crown ether and TPB 36 Stt.010.Mssv.BKD002ac.email.ninhd 77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77t@edu.gmail.com.vn.bkc19134.hmu.edu.vn.Stt.010.Mssv.BKD002ac.email.ninhddtt@edu.gmail.com.vn.bkc19134.hmu.edu.vn C.33.44.55.54.78.65.5.43.22.2.4 22.Tai lieu Luan 66.55.77.99 van Luan an.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.33.44.55.54.78.655.43.22.2.4.55.22 Do an.Tai lieu Luan van Luan an Do an.Tai lieu Luan van Luan an Do an LIST OF ABBREVIATIONS SPE Solid phase extraction Vortex-assisted liquid–liquid micro- VALLME extraction Solid phase extraction combined with SPE-VALLME vortex-assisted liquid–liquid microextraction PPB Part per billion PPM Part per million Sr Strontium IC Ion chromatography DIW Deionised water High Performance Liquid HPLC Chromatography Gas chromatography–mass GC-MS spectrometry Stt.010.Mssv.BKD002ac.email.ninhd 77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77t@edu.gmail.com.vn.bkc19134.hmu.edu.vn.Stt.010.Mssv.BKD002ac.email.ninhddtt@edu.gmail.com.vn.bkc19134.hmu.edu.vn 10 C.33.44.55.54.78.65.5.43.22.2.4 22.Tai lieu Luan 66.55.77.99 van Luan an.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.33.44.55.54.78.655.43.22.2.4.55.22 Do an.Tai lieu Luan van Luan an Do an.Tai lieu Luan van Luan an Do an PART IV: RESULTS In this study, we use two methods for determination strontium Firstly, solid phase extraction (SPE) and the results will be shown below:  100ml solution sample included: 1ppm Sr2+, 3M HNO3, DIW When we increased the sample volume (100ml), after heating ml solution divide bottle (#1 and #2) time and put in the IC machine We get the results: In chromatography graph, we can see that the signals at sample #1 and #2 are higher than sample #3 and #4 The peak areas of sample #1 and #2 are 88.55; 269.47 respectively While the number of #3 and #4 are 80.83 and respectively Therefore, when heating the solution to make sure pH of this solution increased, the peak area increased Following by the peak area, we calculate the total recovery of strontium when used 100ml 1ppm Sr2+ 3M HNO3 is approximately 81% This results is a reason explain why when we combination two methods SPE-VALLME we used 3M HNO3 Figure 4.1 Recovery strontium of 100ml sample volume 3M HNO3 and chromatography graph of samples Stt.010.Mssv.BKD002ac.email.ninhd 77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77t@edu.gmail.com.vn.bkc19134.hmu.edu.vn.Stt.010.Mssv.BKD002ac.email.ninhddtt@edu.gmail.com.vn.bkc19134.hmu.edu.vn 39 C.33.44.55.54.78.65.5.43.22.2.4 22.Tai lieu Luan 66.55.77.99 van Luan an.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.33.44.55.54.78.655.43.22.2.4.55.22 Do an.Tai lieu Luan van Luan an Do an.Tai lieu Luan van Luan an Do an  100ml solution sample included: 1ppm Sr2+, 8M HNO3, DIW When we increased the sample volume (100ml), after heating ml solution divide bottle (#1 and #2) time and put in the IC machine We get the results: In chromatography graph, we can see that the signals at sample #1 and #2 are higher than sample #3 and #4 The peak areas of sample #1 and #2 are 33.3; 119.66 respectively While the number of #3 and #4 are 76.12 and 13.12 respectively Therefore, when heating the solution to make sure pH of this solution increased, the peak area increased Following by the peak area, we calculate the total recovery of strontium when used 100ml 1ppm Sr2+ 8M HNO3 is approximately 45% Figure 4.2 Recovery strontium of 100ml sample volume 8M HNO3 and chromatography graph of samples Stt.010.Mssv.BKD002ac.email.ninhd 77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77t@edu.gmail.com.vn.bkc19134.hmu.edu.vn.Stt.010.Mssv.BKD002ac.email.ninhddtt@edu.gmail.com.vn.bkc19134.hmu.edu.vn 40 C.33.44.55.54.78.65.5.43.22.2.4 22.Tai lieu Luan 66.55.77.99 van Luan an.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.33.44.55.54.78.655.43.22.2.4.55.22 Do an.Tai lieu Luan van Luan an Do an.Tai lieu Luan van Luan an Do an Secondly, we used vortex-assisted liquid-liquid micro-extraction (VALLME) method was applied for the extraction of strontium (II) from the aqueous phase into the organic phase In the first experiment, we the calibration curve to make the linear range of we developed the method to determine strontium at low sample volume 2mL sample volume included : DIW, volume of each concentration strontium, crown ether and extraction solvent (TPB) In this experiment, the amount of TPB 15mM and crown ether in 1-octanol are always a constant; 400uL and 150uL respectively The linear range is 10, 25, 100, 500, 1000, 2000ppb; respectively And we get the results in the chart below (figure 4.3) The typical calibration curve of this figure was y = 0.1366x0.0457 and a corelation coefficient R2 = 0.9998 Peak area Linear Fit of Peak area 300 y = 136.65x - 0.0457 R² = 0.9998 250 Peak area (uS*sec) 200 150 100 50 0.0 0.5 1.0 1.5 2.0 Concentration Sr(II) (ppm) Figure 4.3 Calibration curve of concentration Sr (II) at low volume sample(2mL) Stt.010.Mssv.BKD002ac.email.ninhd 77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77t@edu.gmail.com.vn.bkc19134.hmu.edu.vn.Stt.010.Mssv.BKD002ac.email.ninhddtt@edu.gmail.com.vn.bkc19134.hmu.edu.vn 41 C.33.44.55.54.78.65.5.43.22.2.4 22.Tai lieu Luan 66.55.77.99 van Luan an.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.33.44.55.54.78.655.43.22.2.4.55.22 Do an.Tai lieu Luan van Luan an Do an.Tai lieu Luan van Luan an Do an  Before we experiment increasing sample volume to test the sensitivity of strontium, we found that the amount recoveries 1-octanol when we in solution sample with crown ether, TPB and without it are different The amount 1-octanol recoveries in the sample volume with crown ether, TPB are lower than sample volume without crown ether, TPB And the chart and the table below will be shown the results Table 4.1 Comparison recoveries 1-octanol with and without crown ether and TPB Volume recovery(µL) Volume(µL) With TPB and crown Without TPB and crown ether ether 250 50 65 300 45 85 350 80 90 400 100 210 450 130 250 Stt.010.Mssv.BKD002ac.email.ninhd 77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77t@edu.gmail.com.vn.bkc19134.hmu.edu.vn.Stt.010.Mssv.BKD002ac.email.ninhddtt@edu.gmail.com.vn.bkc19134.hmu.edu.vn 42 C.33.44.55.54.78.65.5.43.22.2.4 22.Tai lieu Luan 66.55.77.99 van Luan an.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.33.44.55.54.78.655.43.22.2.4.55.22 Do an.Tai lieu Luan van Luan an Do an.Tai lieu Luan van Luan an Do an  Without crown ether With crown ether Volume recoveries (uL) 250 200 150 100 50 250 300 350 400 450 Volume (uL) Figure 4.4 Comparison 1-octanol recoveries between solution sample with crown ether, TPB and without crown ether,TPB Stt.010.Mssv.BKD002ac.email.ninhd 77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77t@edu.gmail.com.vn.bkc19134.hmu.edu.vn.Stt.010.Mssv.BKD002ac.email.ninhddtt@edu.gmail.com.vn.bkc19134.hmu.edu.vn 43 C.33.44.55.54.78.65.5.43.22.2.4 22.Tai lieu Luan 66.55.77.99 van Luan an.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.33.44.55.54.78.655.43.22.2.4.55.22 Do an.Tai lieu Luan van Luan an Do an.Tai lieu Luan van Luan an Do an  Effect of volume of extraction solvent: volume of extraction solvent (DtBuCH18C6 in 1-octanol), also influences the extraction efficiency of VADLLME The volume of 4,4’(5’)-bis tert-butylcyclohexano-18-crown-6 in 1-octanol ranging from 10 to 100 µL was considered in the experiment design The change of extraction efficiency with different volume of extraction is show in Fig 4.5 Fig 4.5 showed that with the volume increasing DtBuCH18C6 in 1-octanol between 250-400 µL, the extraction efficiency of strontium (II) increased When the volume of extraction is more than 400 µL, the changes in the extraction efficiency of Sr (II) is decreased Therefore, 400 µL of DtBuCH18C6 in 1-octanol was applied in subsequent experiment Peak area 80 Peak area (uS*sec) 75 70 65 60 55 50 200 250 300 350 400 450 500 550 600 650 Volume extraction (uL) Figure 4.5 Effect of volume of extraction solvent on the extraction efficiency of strontium Extraction condition: volume 50ml, Sr (II) concentration 50 µg/L, 3ml TPB Stt.010.Mssv.BKD002ac.email.ninhd 77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77t@edu.gmail.com.vn.bkc19134.hmu.edu.vn.Stt.010.Mssv.BKD002ac.email.ninhddtt@edu.gmail.com.vn.bkc19134.hmu.edu.vn 44 C.33.44.55.54.78.65.5.43.22.2.4 22.Tai lieu Luan 66.55.77.99 van Luan an.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.33.44.55.54.78.655.43.22.2.4.55.22 Do an.Tai lieu Luan van Luan an Do an.Tai lieu Luan van Luan an Do an  In this experiment, we use the result of previous experiment As we said above, the volume extraction at 400 µL get a highest peak area It’s mean we can get good results at this volume extraction Therefore, when we the calibration curve at high sample volume (50ml), 47 mL of sample solution containing strontium in water was delivered to 50 mL conical bottomed tube, then mL of 50 mM TPB solution and 400 μL of 1-octanol containing 10 mM DtBuCH18C6 were injected And we get the regression analysis for the calibration curves showed a good linear correlation over the range from 0.01 to 0.1 mg L-1, with a coefficient of determination (r2) being better than 0.9993 The enrichment factor (EF) and the extraction recovery (R%) were calculated based on the ratio of slopes of calibration curve before and after VALLME (Wang et al., 2016) Peak area Linear Fit of Peak area 80 70 y = 763.54x - 1.6261 R² = 0.9993 Peak area (uS*sec) 60 50 40 30 20 10 0.00 0.02 0.04 0.06 0.08 0.10 Concentration Sr(II) (ppm) Figure 4.6 Calibration curve of concentration Sr (II) at high volume sample (50mL) Stt.010.Mssv.BKD002ac.email.ninhd 77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77t@edu.gmail.com.vn.bkc19134.hmu.edu.vn.Stt.010.Mssv.BKD002ac.email.ninhddtt@edu.gmail.com.vn.bkc19134.hmu.edu.vn 45 C.33.44.55.54.78.65.5.43.22.2.4 22.Tai lieu Luan 66.55.77.99 van Luan an.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.33.44.55.54.78.655.43.22.2.4.55.22 Do an.Tai lieu Luan van Luan an Do an.Tai lieu Luan van Luan an Do an  This experiment, we will combined two methods: solid phase extraction and vortex-assisted liquid-liquid micro-extraction to test the sensitivity of strontium and then compare with VALLME at low volume sample (2 mL) and high volume sample (50 mL) The results presented in the chart below As we know, the sensitivity and slope of calibration curve are related The sensitivity increased when the slope of calibration curve of this chemical was increased and vice versa Therefore, when we saw in the chart, the slope calibration curve of SPE-VALLME method was highest It was 1.0671 with a correlation coefficient R2= 0.9861 Followed by, the slope of calibration curve when we at high volume sample was 0.7635 with a correlation coefficient R2= 0.9993 and then 0.1366 was the number of the slope when we at low volume sample, a correlation coefficient R2= 0.9998 300 VALLME 50ml SPE-VALLME VALLME 2ml Linear Fit of VALLME 50ml Linear Fit of SPE-VALLME Linear Fit of VALLME 2ml 250 y = 0.1366x - 0.0457 R² = 0.9998 Peak area (uS*sec) 200 150 y = 1.0671x + 13.998 R² = 0.9861 100 y = 0.7635x - 1.6261 R² = 0.9993 50 0 500 1000 1500 2000 Concentration Sr(II) (ppb) Figure 4.7 Comparison solid phase extraction combined with vortex-assisted liquid-liquid micro-extraction and vortex-assisted liquid-liquid micro-extraction at low and high volume Stt.010.Mssv.BKD002ac.email.ninhd 77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77t@edu.gmail.com.vn.bkc19134.hmu.edu.vn.Stt.010.Mssv.BKD002ac.email.ninhddtt@edu.gmail.com.vn.bkc19134.hmu.edu.vn 46 C.33.44.55.54.78.65.5.43.22.2.4 22.Tai lieu Luan 66.55.77.99 van Luan an.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.33.44.55.54.78.655.43.22.2.4.55.22 Do an.Tai lieu Luan van Luan an Do an.Tai lieu Luan van Luan an Do an PART V: DISCUSSION AND CONCLUSION 4.2 Discussion In this study, 47 mL of sample solution containing strontium in water was delivered to 50 mL conical bottomed tube, then mL of 50 mM TPB solution and 400 μL of 1-octanol containing 10 mM DtBuCH18C6 were injected to test the sensitivity enhancement of strontium at high volume sample (50 mL) by ion chromatography machine Although time has been a limit to test but this application was successfully at high sample volume (50 mL) with the detector sensitivity for determination strontium = 0.7635 Base on the results of comparison between the slope of calibration curve and correlation coefficient in figure 4.7 The main advantages of this method high sensitivity, low sample volume and selectivity, save time But the disadvantages of VALLME is not suitable for complex matrixes (namely highly saline solution) while the advantages of SPE are trace enrichment (pre-concentration), matrix simplification (sample clean-up) and medium exchange Therefore, in this study, we already combined two methods SPE-VALLME and the result also showed in figure 10 In this figure, the slope of SPE-VALLME was highest (1.0671), it means we can get good result for determination strontium by ion chromatography Although SPE-VALLME might have some negative point made the results of solution not clear enough and our skills was very important when we this method because of the amount of substance used in the experiment is very small (normally using µL unit) Stt.010.Mssv.BKD002ac.email.ninhd 77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77t@edu.gmail.com.vn.bkc19134.hmu.edu.vn.Stt.010.Mssv.BKD002ac.email.ninhddtt@edu.gmail.com.vn.bkc19134.hmu.edu.vn 47 C.33.44.55.54.78.65.5.43.22.2.4 22.Tai lieu Luan 66.55.77.99 van Luan an.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.33.44.55.54.78.655.43.22.2.4.55.22 Do an.Tai lieu Luan van Luan an Do an.Tai lieu Luan van Luan an Do an 4.3 Conclusion In conclusion, in this research, we have successfully examined the sensitivity enhancement of strontium by ion chromatography with SPE and large sample volume combined with VALLME The main advantages of vortex-assisted liquid-liquid microextraction method are high sensitivity, low cost, simplicity of operation and it has the inherent advantage of achieving equilibrium conditions within only a few minutes To avoid the interference of complex matrixes, combined SPE-VALLME to reduce this restriction of VALLME method Stt.010.Mssv.BKD002ac.email.ninhd 77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77t@edu.gmail.com.vn.bkc19134.hmu.edu.vn.Stt.010.Mssv.BKD002ac.email.ninhddtt@edu.gmail.com.vn.bkc19134.hmu.edu.vn 48 C.33.44.55.54.78.65.5.43.22.2.4 22.Tai lieu Luan 66.55.77.99 van Luan an.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.33.44.55.54.78.655.43.22.2.4.55.22 Do an.Tai lieu Luan van Luan an Do an.Tai lieu Luan van Luan an Do an REFERENCES Bagchi, R., & Haddad, P (1986) Contamination sources in the clean-up of samples for inorganic ion analysis Journal of Chromatography A, 351, 541-547 Barceló, D (1997) Trace Determination of Pesticides and their Degradation Products in Water (BOOK REPRINT) (Vol 19): Elsevier Barceló, D., & Hennion, M.-C (1995) On-line sample handling strategies for the trace-level determination of pesticides and their degradation products in environmental waters Analytica Chimica Acta, 318(1), 1-41 Berrueta, L., Gallo, B., & Vicente, F (1995) A review of solid phase extraction: basic principles and new developments Chromatographia, 40(7-8), 474-483 Brinkman, U T (1994) On-line sample treatment for or via column liquid chromatography Journal of Chromatography A, 665(2), 217-231 Brouwer, E., Kofman, S., & Brinkman, U T (1995) Selected procedures for the monitoring of polar pesticides and related microcontaminants in aquatic samples Journal of Chromatography A, 703(1-2), 167-190 Bruland, K., Middag, R., & Lohan, M (2013) Controls of trace metals in seawater Chen, H., Chen, H., Ying, J., Huang, J., & Liao, L (2009) Dispersive liquid–liquid microextraction followed by high-performance liquid chromatography as an efficient and sensitive technique for simultaneous determination of chloramphenicol and thiamphenicol in honey Analytica Chimica Acta, 632(1), 80-85 Chiron, S., Fernandez Alba, A., & Barcelo, D (1993) Comparison of on-line solid-phase disk extraction to liquid-liquid extraction for monitoring selected pesticides in environmental waters Environmental science & technology, 27(12), 2352-2359 Stt.010.Mssv.BKD002ac.email.ninhd 77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77t@edu.gmail.com.vn.bkc19134.hmu.edu.vn.Stt.010.Mssv.BKD002ac.email.ninhddtt@edu.gmail.com.vn.bkc19134.hmu.edu.vn 49 C.33.44.55.54.78.65.5.43.22.2.4 22.Tai lieu Luan 66.55.77.99 van Luan an.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.33.44.55.54.78.655.43.22.2.4.55.22 Do an.Tai lieu Luan van Luan an Do an.Tai lieu Luan van Luan an Do an De Castro, M L., & Priego-Capote, F (2007) Ultrasound-assisted preparation of liquid samples Talanta, 72(2), 321-334 De Rosa, C., El-Masri, H., Pohl, H., Cibulas, W., & Mumtaz, M (2004) Implications of chemical mixtures in public health practice Journal of Toxicology and Environmental Health, Part B, 7(5), 339-350 Ding, S., Yang, Y., Huang, H., Liu, H., & Hou, L.-a (2015) Effects of feed solution chemistry on low pressure reverse osmosis filtration of cesium and strontium Journal of hazardous materials, 294, 27-34 Du, J., Yan, H., She, D., Liu, B., & Yang, G (2010) Simultaneous determination of cypermethrin and permethrin in pear juice by ultrasound-assisted dispersive liquidliquid microextraction combined with gas chromatography Talanta, 82(2), 698-703 Fattahi, N., Samadi, S., Assadi, Y., & Hosseini, M R M (2007) Solid-phase extraction combined with dispersive liquid–liquid microextraction-ultra pre-concentration of chlorophenols in aqueous samples Journal of Chromatography A, 1169(1–2), 63-69 doi: https://doi.org/10.1016/j.chroma.2007.09.002 Font, G., Manes, J., Molto, J., & Pico, Y (1993) Solid-phase extraction in multi-residue pesticide analysis of water Journal of Chromatography A, 642(1-2), 135-161 Fritz, J S., Dumont, P J., & Schmidt, L W (1995) Methods and materials for solid-phase extraction Journal of Chromatography A, 691(1-2), 133-140 Geerdink, R., Niessen, W., & Brinkman, U T (2002) Trace-level determination of pesticides in water by means of liquid and gas chromatography Journal of Chromatography A, 970(1), 65-93 Hennion, M.-C., Cau-Dit-Coumes, C., & Pichon, V (1998) Trace analysis of polar organic pollutants in aqueous samples: Tools for the rapid prediction and optimisation of the solid-phase extraction parameters Journal of Chromatography A, 823(1), 147-161 Stt.010.Mssv.BKD002ac.email.ninhd 77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77t@edu.gmail.com.vn.bkc19134.hmu.edu.vn.Stt.010.Mssv.BKD002ac.email.ninhddtt@edu.gmail.com.vn.bkc19134.hmu.edu.vn 50 C.33.44.55.54.78.65.5.43.22.2.4 22.Tai lieu Luan 66.55.77.99 van Luan an.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.33.44.55.54.78.655.43.22.2.4.55.22 Do an.Tai lieu Luan van Luan an Do an.Tai lieu Luan van Luan an Do an Horwitz, E., Dietz, M., & Fisher, D (1990) Extraction of stoontium from nitric acid solutions using dicyclohexano-18-crown-5 and its derivatives Solvent Extraction and Ion Exchange, 8(4-5), 557-572 Horwitz, E P., Dietz, M L., & Fisher, D E (1991) Separation and pre-concentration of strontium from biological, environmental, and nuclear waste samples by extraction chromatography using a crown ether Analytical Chemistry, 63(5), 522-525 Jia, C., Zhu, X., Wang, J., Zhao, E., He, M., Chen, L., & Yu, P (2010) Extraction of pesticides in water samples using vortex-assisted liquid–liquid microextraction Journal of Chromatography A, 1217(37), 5868-5871 Lerouge, C., Gaucher, E C., Tournassat, C., Négrel, P., Crouzet, C., Guerrot, C., Buschaert, S (2010) Strontium distribution and origins in a natural clayey formation (Callovian-Oxfordian, Paris Basin, France): A new sequential extraction procedure Geochimica et Cosmochimica Acta, 74(10), 2926-2942 Liu, X., Li, J., Zhao, Z., Zhang, W., Lin, K., Huang, C., & Wang, X (2009) Solid-phase extraction combined with dispersive liquid-liquid microextraction for the determination for polybrominated diphenyl ethers in different environmental matrices Journal of Chromatography A, 1216(12), 2220-2226 doi: 10.1016/j.chroma.2008.12.092 Mohite, B., & Khopkar, S (1987) Solvent extraction separation of strontium as 18-crown-6 complex with picrate ion Analytical Chemistry, 59(8), 1200-1203 Montes, R., Rodríguez, I., Ramil, M., Rubí, E., & Cela, R (2009) Solid-phase extraction followed by dispersive liquid-liquid microextraction for the sensitive determination of selected fungicides in wine Journal of Chromatography A, 1216(29), 5459-5466 doi: 10.1016/j.chroma.2009.05.048 Stt.010.Mssv.BKD002ac.email.ninhd 77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77t@edu.gmail.com.vn.bkc19134.hmu.edu.vn.Stt.010.Mssv.BKD002ac.email.ninhddtt@edu.gmail.com.vn.bkc19134.hmu.edu.vn 51 C.33.44.55.54.78.65.5.43.22.2.4 22.Tai lieu Luan 66.55.77.99 van Luan an.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.33.44.55.54.78.655.43.22.2.4.55.22 Do an.Tai lieu Luan van Luan an Do an.Tai lieu Luan van Luan an Do an Pena-Pereira, F., Lavilla, I., & Bendicho, C (2010) Liquid-phase microextraction techniques within the framework of green chemistry TrAC Trends in Analytical Chemistry, 29(7), 617-628 doi: http://dx.doi.org/10.1016/j.trac.2010.02.016 Regueiro, J., Llompart, M., Garcia-Jares, C., Garcia-Monteagudo, J C., & Cela, R (2008) Ultrasound-assisted emulsification–microextraction of emergent contaminants and pesticides in environmental waters Journal of Chromatography A, 1190(1), 27-38 Rezaee, M., Assadi, Y., Milani Hosseini, M R., Aghaee, E., Ahmadi, F., & Berijani, S (2006) Determination of organic compounds in water using dispersive liquid-liquid microextraction J Chromatogr A, 1116(1-2), 1-9 doi: 10.1016/j.chroma.2006.03.007 Sanchez-Prado, L., Barro, R., Garcia-Jares, C., Llompart, M., Lores, M., Petrakis, C., Psillakis, E (2008) Sonochemical degradation of triclosan in water and wastewater Ultrasonics sonochemistry, 15(5), 689-694 Sha, Y., Deng, C., & Liu, B (2008) Development of C18-functionalized magnetic silica nanoparticles as sample preparation technique for the determination of ergosterol in cigarettes by microwave-assisted derivatization and gas chromatography/mass spectrometry J Chromatogr A, 1198-1199, 27-33 doi: 10.1016/j.chroma.2008.05.049 Vajda, N., & Kim, C.-K (2010) Determination of radiostrontium isotopes: a review of analytical methodology Applied Radiation and Isotopes, 68(12), 2306-2326 Wang, C.-Y., Tung, S.-Y., Lo, Y.-S., Huang, H.-L., Ko, C.-H., & Wu, C.-H (2016) Sensitivity enhancement in the fluorometric determination of aliphatic amines using naphthalene-2, 3-dicarboxaldehyde derivatization followed by vortex-assisted liquid– liquid microextraction Talanta, 152, 475-481 Wu, Q., Wang, C., Liu, Z., Wu, C., Zeng, X., Wen, J., & Wang, Z (2009) Dispersive solidphase extraction followed by dispersive liquid-liquid microextraction for the determination of some sulfonylurea herbicides in soil by high-performance liquid Stt.010.Mssv.BKD002ac.email.ninhd 77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77t@edu.gmail.com.vn.bkc19134.hmu.edu.vn.Stt.010.Mssv.BKD002ac.email.ninhddtt@edu.gmail.com.vn.bkc19134.hmu.edu.vn 52 C.33.44.55.54.78.65.5.43.22.2.4 22.Tai lieu Luan 66.55.77.99 van Luan an.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.33.44.55.54.78.655.43.22.2.4.55.22 Do an.Tai lieu Luan van Luan an Do an.Tai lieu Luan van Luan an Do an Stt.010.Mssv.BKD002ac.email.ninhd 77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77t@edu.gmail.com.vn.bkc19134.hmu.edu.vn.Stt.010.Mssv.BKD002ac.email.ninhddtt@edu.gmail.com.vn.bkc19134.hmu.edu.vn