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Analytical Chemistry (II)

Analytical Chemistry (II) ---------------------------------------------------------------------------------- Instructor: 魏國佐 Office: 數學館 524 (x-66406)Lab: 化學館 424 (x-661406) --------------------------------------------------------------------------------- Course contents:

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Analytical Chemistry (II)

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  1. Analytical Chemistry (II) ---------------------------------------------------------------------------------- Instructor: 魏國佐 Office:數學館524 (x-66406)Lab: 化學館424 (x-661406) --------------------------------------------------------------------------------- Course contents: Basic concepts of instrumental analysis (R1;ch. 5; R2:ch. 1) Analytical separations (R1:ch. 23-26; R2: ch. 26-30) Mid-term 5/4 19:00 50% 3. Spectrochemical analysis (R1;ch. 19-22; R2: ch. 6-10, ch. 13-14) Final exam. 6/22 19:00 40% References: Quantitative chemical analysis 6th ed.by Daniel C. Harris. Principles of instrumental analysis th ed. By Skoog/Holler/Crouch

  2. The Twelve Principles of Green Chemistry* • Prevention: It is better to prevent waste than to treat or clean up waste after it has been created. • 預防：防止廢棄物的產生比在廢棄物被產生之後的再處理或是清理更有效。 • 2. Atom Economy: Synthetic methods should be designed to maximize the incorporation of all materials used in the process into the final product. • 原子效率：合成方法的設計，應該使得生產過程中所採用的原料能最大量地轉換成產物 • 3. Less Hazardous Chemical Syntheses: Wherever practicable, synthetic methods should be designed to use and generate substances that possess little or no toxicity to human health and the environment. • 減少有害的化學合成：在考量合成方法的設計時，僅可能讓所使用或產生的物質對於人類的健康和整個環境具有最少甚至沒有毒害。 • 4. Designing Safer Chemicals: Chemical products should be designed to effect their desired function while minimizing their toxicity. • 設計較安全的化學製品：化學產品的設計，應該考量具有高效的功能同時使其毒害最小化。 What Is Green Chemistry? Green chemistry is the design of chemical products and processes that reduce or eliminate the use and generation of hazardous substances.

  3. 5. Safer Solvents and Auxiliaries: The use of auxiliary substances (e.g., solvents, separation agents, etc.) should be made unnecessary wherever possible and innocuous when used. 安全的溶劑和輔助劑：儘可能的避免使用輔助物質(如:溶劑、分離試劑等)，假如無法避免，也要選用無毒害的。 6. Design for Energy Efficiency: Energy requirements of chemical processes should be recognized for their environmental and economic impacts and should be minimized. If possible, synthetic methods should be conducted at ambient temperature and pressure. 能源效益的設計：在化學的製程中所需的能源，應該考慮其對環境和經濟的影響，並且設法降低耗能，僅可能採用在常溫常壓下的合成方法。 • Use of Renewable Feedstocks: A raw material or feedstock should be renewable rather than depleting whenever technically and economically practicable. 使用可再生資源：在技術和經濟可行的前題之下，要採用可再生代替消耗性的原料。 8. Reduce Derivatives: Unnecessary derivatization (use of blocking groups, protection/ deprotection, temporary modification of physical/chemical processes) should be minimized or avoided if possible, because such steps require additional reagents and can generate waste. 減少衍生物：儘量別使用不必要的衍生物，例如：保護或去保護作用、改變物理或化學特牲的臨時修飾。因為這些步驟需要額外的試劑並且可能產生廢棄物。

  4. 9. Catalysis: Catalytic reagents (as selective as possible) are superior to stoichiometric reagents. 催化作用：具有高選擇性的催化試劑比起化學計量助劑更佳。 10. Design for Degradation: Chemical products should be designed so that at the end of their function they break down into innocuous degradation products and do not persist in the environment. 產品遞降分解：化學產品應該設計在當它們功能結束後，可分解或可降解成無害產物，並且不會永存於環境中。 11. Real-time analysis for Pollution Prevention: Analytical methodologies need to be further developed to allow for real-time, in-process monitoring and control prior to the formation of hazardous substances. 對於汙染預防的即時處理分析：更進一步發展分析的方法，使其能進行線上即時監控，以便在有害物質形成之前加以控制。 12. Inherently Safer Chemistry for Accident Prevention: Substances and the form of a substance used in a chemical process should be chosen to minimize the potential for chemical accidents, including releases, explosions, and fires. 意外事故的預防：選擇化學生產過程的物質，將化學意外事故(滲透、爆炸、火災等)的危險性降低至最小程度。

  5. Extraction of Metal Ions with RTIL • 利用RTIL在重金屬離子之萃取,實驗時使用金屬螯合物, RTIL(在此選用不溶於水的1-butyl-3-methylimidazolium hexafluorophosphate , [BMIM][PF6]) 當有機層進行金屬離子的萃取，以便探討RTIL取代揮發性溶劑於金屬離子之萃取的可行性. • Guor-Tzo Wei*, Zusing Yang, Chao-Jung Chen, Anal. Chimica, Acta 2003, 488(2), 183. • Guor-Tzo Wei*, Jin-Chu Chen, Zusing Yang, J. Chin. Chem. Soc. 2003, 50, 1123.

  6. 傳統液-液相萃取: 需使用大量有毒、易燃、高揮發性的有機溶劑. 近代液-液相萃取: a.使用supercritical fluid CO2萃取 b.使用不具揮發性、不可燃、毒性較低的ionic liquid(IL) ，且可回收使用。

  7. Presidential Green Chemistry Challenge Awardshttp://www.epa.gov/greenchemistry/ Mission:To promote innovative chemical technologies that reduce or eliminate the use or generation of hazardous substances in the design, manufacture, and use of chemical products. 1996: Alternative Synthetic Pathways Award: Monsanto Company, The Catalytic Dehydrogenation of Diethanolamine Alternative Solvents/Reaction Conditions Award: Dow Chemical The Development and Commercial Implementation of 100 Percent Carbon Dioxide as an Environmentally Friendly Blowing Agent f or the Polystyrene Foam Sheet Packaging Market Designing Safer Chemicals Award: Rohm and Haas Designing an Environmentally Safe Marine Antifoulant Small Business Award: Donlar Corporation Production and Use of Thermal Polyaspartic Acid Academic Award : Prof. Mark Holtzapple, Texas A&M Univ. Conversion of Waste Biomass to Animal Feed, Chemicals, and Fuels

  8. What is a Room Temperature Ionic Liquid (RTIL)?(Room Temperature Molten Salt) • Liquid salt consisting of at least one organic component (cation or anion) with melting pointbelow room temperature • Properties: • Negligible vapor pressure • High thermal stability (~250-400°C) • High viscosity • Hydrophobic or hydrophilic • Dissolve many organic, organometallic, and inorganic compounds RTILs are regarding as “Green solvents”

  9. Ethyl ammonium nitrate (EtNH+3)(NO-3), which has a melting point of 12°C, was first described in 1914. P. Walden, Bull. Acad. Imper. Sci. (St. Petersburg) 1800 (1914). Osteryoung & Wilks, late1970, chloroaluminate salts in electrochemistry Sneddon & Hussey, 1980, groups chloroaluminate salts in electrochemistry and organometallic researches. After 1990, used as solvents for synthesis Late 2000, the application in separation

  10. Pure Appl. Chem., 2000, 72, 2275–2287

  11. RTIL Structures • Cations • Anions • PF6-SbF6- • BF4-CF3SO3- (TfO) • Cl-N(CF3SO2)2- (NTf2) R: methyl; R’: n-butyl 1-butyl-3-methylimidazolium, BMIM, C4MIM 1-butyl-3-methylimidazolium hexafluorophosphate [BMIM][PF6] 1-octyl-3-methylimidazotetrafluoroborate [OMIM][BF4]

  12. General syntheses of ionic liquid: Green Chemistry, 2003. 5. 181-186.

  13. Effect of the nature of anion on physical properties of BMIM salt ----------------------------------------------------------------------------------- Anion m.p. d Viscosity Conductivity oC g/cm3 cP (20oC) S/m ---------------------------------------------------------------------------------- BF4- -82(g) 1.17 233 0.17 PF6- -8 1.36 312 0.14 Cl- 65 1.10 solid solid CF3COO- ~-40(g) 1.21 73 0.32 CF3SO3- 16 1.29 90 0.37 (CF3SO2)N- -4 1.43 52 0.39 C3F7COO- ~-40(g) 1.33 182 0.10 C4F9SO3- 20 1.47 373 0.045 ---------------------------------------------------------------------------------- (g) Glass transition P.S. viscosity of water 1 cP.

  14. Dissolution of Cellulose with Ionic Liquids R.P. Swatloski, R.D. Rogers, et al. J.A.C.S. 124 (2002) 4974.

  15. Room-temperature ionic liquids: a novel versatile lubricantChengfeng Ye , Weimin Liu , Yunxia Chen and Laigui Yu, Chem. Commun., 2001, (21), 2244 - 2245 Alkylimidazolium tetrafluoroborates are promising versatile lubricants for the contact of steel/steel, steel/aluminium, steel/copper, steel/SiO2, Si3N4/SiO2, steel/Si(100), steel/sialon ceramics and Si3N4/sialon ceramics; they show excellent friction reduction, antiwear performance and high load-carrying capacity

  16. Uses of RTILs in Anal. Chem. • Novel solvents in liquid-liquid or micro extractions • Run buffer additives in CE • Matrixes in Matrix-Assisted Laser Desorption Ionization (MALDI) mass spectrometry • Stationary phases in gas-liquid chromatography

  17. Extraction of Metal Ions with RTIL Illustration of various equilibra involved in metal ion extraction with ionic liquid .

  18. 鉛與dithizone結合示意圖 colorless metal complex (red)

  19. + + 2 Cu2+ 2H+ Dithizone Blue Green Violet + + Cu2+ 2 2H+ Oxine Blue Yellow + 2 2H+ + Cu2+ PAN Blue Orange Red

  20. The pH value effect on the extraction of lead ion with dithizone in ( ) ionic liquid, ( ) chloroform.

  21. Comparing the extraction of copper ions with ionic liquid and dichloromethane with PAN

  22. The effect of pH value on the extraction efficiencies of metal ions with dithizone by IL.

  23. The effect of pH value on the extraction efficiencies of metal ions with PAN by IL.

  24. Hg2+ Zn2+ Pb2+ Ca2+ Cr3+ Mn2+ Cd2+ As5+Co2+ Ag+ The effect of 100 ppm cation on the extraction of 5 ppm Cu2+ with dithizone

  25. SCN- citrate Cl- CO32- PO43- CH3COO- The effect of 100 ppm anion on the extraction of 5 ppm Cu2+ with dithizone

  26. SCN- citrate Cl- CO32- PO43- CH3COO- The effect of 100 ppm anion on the extraction of 5 ppm Cu2+ with PAN

  27. Preconcentration of Pb2+

  28. (a) Separation of different metal ions; (b) Reproducibility of Cadmium ions with reusal [C4MIM][PF6] Average = 43.31% RSD = 5.69% (a) (b)

  29. 1. (10%) A least square linear regression of the standards for an instrument obtained : Y = 2.70 + 5.23 X, where X is the concentration (in ng/mL) of an analyte. The standard deviation of determination S is 0.043. Find the limit of detection. 2. (10 %) A known mixture of compounds A and B gave the following HPLC results: Compound Conc. (mg/mL in mixture) Peak area (cm2) A 1.03 10.86 B 1.16 4.37 A solution was prepared by mixing 12.29 mg of B plus 10.00 mL of unknown containing just A, and diluting to 25.00 mL. Peak area of 5.79 and 6.28 cm2 were observed for A and B, respectively. Find the concentration of A (mg/mL) in the unknown.

  30. 1. (10 %) A known mixture of compounds A and B gave the following HPLC results: Compound Conc. (mg/mL in mixture) Peak area (cm2) A 1.03 10.86 B 1.16 4.37 A solution was prepared by mixing 12.29 mg of B plus 10.00 mL of unknown containing just A, and diluting to 25.00 mL. Peak area of 5.79 and 6.28 cm2 were observed for A and B, respectively. Find the concentration of A (mg/mL) in the unknown.

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