摘要
随着科学技术的发展,在进行地质、生物、环境等样品的分析时,经常要求测定ng/mL甚至pg/mL级的痕量元素,虽然原子光谱分析技术具有很高的灵敏度,但要直接测定这些试样中的痕量组分往往会遇到困难,有时甚至是不可能的,这是因为,一方面,样品本身的物理化学状态有的不适合直接测定,或者分析方法对极低含量的组分灵敏度不够;另一方面是存在基体干扰,或者缺乏相应的校正标准和试剂。因此需要借助于分离富集技术来提高分析方法的灵敏度和选择性。
浊点萃取是近年来出现的一种新兴的液-液萃取技术,它不使用挥发性有机溶剂,不影响环境。它以中性表面活性剂胶束水溶液的溶解性和浊点现象为基础,通过改变实验参数引发相分离,将疏水性物质与亲水性物质分离。作为一种分离富集的手段,因其具有萃取效率高、富集因子大、操作简便、安全、经济、便于实现联用化等优点,受到人们的极大关注与重视,并在生物大分子的分离纯化、有机小分子的分离测定及金属离子的分离富集等方面得到广泛的应用。
浊点萃取技术已被用于痕量元素的分离富集和形态分析中,它能够与多种检测技术联用,其中分光光度法一直是与之联用的主要检测手段之一,这种联用技术又被称为析相光度法。由于需要将胶束相稀释到一定体积进行吸光度测定,故该法的富集倍数受到一定限制。而在与原子光谱检测技术联用时,为了降低表面活性剂相的粘度,常规的处理是用一定体积的含稀酸的甲醇溶液稀释表面活性剂相。有机溶剂和表面活性剂的引入会对测定产生影响,特别是在ICP-AES分析中,有机物的引入一方面对光谱信号有一定的增敏效应,另一方面有机物分解时吸收较大能量,会导致ICP放电不稳定甚至熄灭。因此将CPE与ICP-AES联用时,多采用一些特殊的进样技术,如电热蒸发、超声雾化、氢化物发生等,在进入等离子体前将有机物除去。迄今为止,采用常规的气动雾化进样CPE-ICP-AES进行痕量金属元素分离分析的报道尚不多见。
⑥
硕士学位论文
MASTER’5 THESIS
本论文的目的是,以原子光谱分析技术为检测手段,对影响金属离子浊点
萃取效率的主要因素进行系统地研究,并将其应用于实际样品中痕量金属离子
的分离富集及形态分析。主要研究内容概括如下:
(l)采用ICP一AES作为检测手段,系统地研究影响过渡金属离子铬和铜浊
点萃取效率的各种因素,确定最佳的萃取条件,并将其应用于环境水样中上述
痕量元素的分离和测定:
(2)采用FAAS作为检测手段,对影响金属离子钻的浊点萃取效率的各种
因素进行研究,确定最佳的萃取条件,并将其应用于环境水样中痕量钻的分离
和测定;
(3)将浊点萃取技术应用于铬的形态分析,采用ICP一AES作为检测手段,
以PMBP为络合剂,根据PMBP对cr(m)和Cr(VI)络合性能的差异,在选定的
pH值条件下实现了对两者的选择性分离测定,建立了一种铬的形态分析的新
方法。
Sensitive, rapid, reproducible, simple and accurate analytical methods are required for the determination of trace elements in geological, biological and environmental samples. The direct determination of extremely low concentrations of trace elements by modern atomic spectroscopic methods, such as atomic absorption spectrometry (AAS) and inductively coupled plasma atomic emission spectrometry (ICP-AES) is often difficult. The limitations are associated not only with the insufficient sensitivity of these techniques but also with matrix interference. For this reason, the separation and preconcentration of trace elements is often required.
Cloud point extraction (CPE) is a kind of new environmentally benign liquid-liquid extraction method. The technique is based on the property of most non-ionic surfactants in aqueous solutions to form micelles and become turbid when heated to a temperature known as the cloud point temperature. Above the cloud point, the micellar solution separates into a surfactant-rich phase of a small volume and a diluted aqueous phase, in which the surfactant concentration is close to the critical micellar concentration (CMC). Any analyte solubilized in the hydrophobic core of the micelles will separate and become concentrated in the small volume of the surfactant-rich phase. The small volume of the surfactant-rich phase obtained with this methodology permits the design of extraction schemes that are simple, economical, highly efficient, speedy, and of lower toxicity to the environment than those extractions that use organic solvents. Separation and preconcentration based on cloud point extraction is becoming an important and practical application in the use of surfactants in analytical chemistry. It's widely used in the separation and purification of bio-molecules and extraction of organic compounds and metal ions.
This sort of extraction can be implemented in conjunction with different
analytical detection systems. Cloud point extraction in connection with spectrophotometry can emerge as a powerful analytical technique for metal preconcentration and determination. CPE has also been the subject of study in metal analysis in connection with atomic spectrometry. The addition of a diluting solution in the surfactant-rich phase is always indispensable in order to obtain a clear and homogenous solution of low viscosity compatible with the requirements of flame and plasma nebulizers. However, the presence of methanol and surfactant in the flame of AAS and plasma have effects on various parameters, such as excitation conditions, plasma stability, nebulizer flows and so on. It was recently proposed to use it in conjunction with detection by electrothermal vaporization, ultrasonic nebulization or hydride generation ICP-AES for the determination of metal ions. According to our knowledge, up to now, applications based on CPE-ICP-AES, along with conventional pneumatic nebulization of the developed methods in trace analysis have seldom been reported.
The aim of this dissertation is to systematically study on the cloud-point extraction and its application to the separation/preconcentration and speciation of metal ions. The major contents are described as follows:
1. A new method for the determination of trace chromium and copper in water samples by inductively coupled plasma optical emission spectrometry after cloud point extraction was proposed. The effect of experimental conditions such as pH, concentration of chelating agent and surfactant, equilibration temperature and time on cloud point extraction was studied. The. chemical variables affecting the separation and extraction recovery were optimized. The proposed method was applied to the simultaneous determination of these elements in real samples.
2. A new method for the determination of trace cobalt in water samples by flame atomic absorption spectrometry after cloud point extraction was proposed. The effect of experimental conditions such as pH, concentration of chelating agent and surfactant, equilibration temperature and time on cloud point
引文
[1] 谷学新,邹洪,朱若华,分析试验室,2001,20(3):96-108
[2] Watanabe H, Tanaka H, Talanta, 1978, 25:585-589
[3] Bordier T M, Biol. Chem., 1981, 256:1604-1607
[4] Quina F H, Hinze W L, Ind. Eng. Chem. Res., 1999, 38:4150-4168
[5] 莫小刚,刘尚营,化学通报,2001,(8):483-487
[6] Pramauro E, In Ordered Media in Chemical Separations, ACS Symposiam Series, Washington, 1987: Chpt 7
[7] Minuth T, Thommes J, Kula M R, Biotechnol. Appl. Biochem., 1996, 23: 107-116
[8] Chiang C L, J. Chin. Inst. Chem. Eng., 1999, 30(2): 171-176
[9] Bompensieri S, Gonzalez R, Kok R, Miranda M V, Nutgeren-Roodzant I, Hellingwerf K J, Cascone O, Nudel B C, Biotechnol. Appl. Biochem., 1996, 23: 77-81
[10] Heegaard N H H, Jakobsen D R, Klattschou D, Anal: Biochem., 1997, 153: 259-262
[11] Tani H, Ooura T, Kamidate T, Damataki T, Watanabe H, J. Chromatogr. B, 1998, 708:294-298
[12] Sirimanne S R, Jr D G P, Ma L, Jr J B J, J. Chromatogr. B, 1998, 716:129-137
[13] Cordero B M, Pavon J L P, Pinto C G; Laespada M E F, Talanta, 1993, 40(11): 1703-1710
[14] Sutcliffe I C, Hogg S D, J. Microbio. Methods, 1993, 17:215-225
[15] Sojo M M, Nunez-Delicado E, Garcia-Carmona F, Sanchez-Ferrer A, J. Agric. Food Chem., 1998, 46:4924-4930
[16] Nunez-Delicado E, Bru R, Sanchez-Ferrer A, Gareia-Carmona F, J. Chromatogr. B, 1996, 680:105
[17] Andersen M D, Moller B L, Protein Expression and Purification, 1998, 13: 366-372
[18] Ko Y G, Thompson G A, Anal. Biochem., 1995, 224:166-172
[19] Lee C K, Su W D, Sep. Sci. Technol., 1998, 33(7): 1003-1012
[20] Schwarz A, Terstappen G C, Futerman A H, Anal. Biochem., 1997, 254: 221-225
[21] Saltoh T, Hinze W L, Talanta, 1995, 42(1): 119-127
[22] Liu C L, Kamei D T, King J A, Wang D I C, Blankschtein D, J. Chromatogr. B, 1998, 711:127-138
[23] Nikas Y J, Liu C L, Srivastava T, Abbott N L, Blankschtem D, Macromolecules, 1992, 25:4797-4806
[24] Liu C L, Nikas Y J, Biotechnol. Bioeng., 1996, 52:185-192
[25] Sivars U, Bergfeldt K, Piculell L, Tjerneld F, J. Chromatogr. B, 1996, 680: 43-53
[26] Garg N, Galaev I Y, Biotechnol. Appl. Biochem, 1994, 20:199
[27] Pinto C G, Pav(?)n J L P, Cordero B M, Anal. Chem., 1994, 66(6): 874-881
[28] Ferrer R, Beltr(?)n J L, Guiteras J, Anal. Chim. Acta, 1996, 330:199-206
[29] Pino V, Ayala J H, Afonso A M, Gonz(?)lez V, Fresenius' J. Anal. Chem., 2001, 371:526-531
[30] Merino F, Rubio S, P(?)rez-Bendito D, J. Chromatogr. A, 2002, 962:1-8
[31] Sicilia D, Rubio S, P(?)rez-Bendito D, Maniasso N, Zagatto E A G, Anal. Chim. Acta, 1999, 392:29-38
[32] Sirimanne S R, Barr J R, Patterson D G, J. Microcolumn Sep., 1999, 11(2): 109-116
[33] Fern(?)ndez A E, Ferrera Z S, Rodriguez J J S, Anal. Chim. Acta, 1998, 358:
145-155
[34] Fern(?)ndez A E, Ferrera Z S, Rodriguez J J S, Analyst, 1999, 124, 487-491
[35] Sanz C P, Ferrera Z S, Rodr(?)guez J J S, Anal. Chim. Acta, 2002, 470:205-214
[36] Pinto C G; Pav(?)n J L P, Cordero B M, Anal. Chem., 1995, 67(15): 2606-2612
[37] Martinez R C, Gonzalo E R, Jim(?)nez M G G, Pinto C G, Pav(?)n J L P, M(?)ndez J H, J. Chromatogr. A, 1996, 754:85-96
[38] Evdokimov E, Wandruszka R V, Anal. Lett., 1998, 31(13): 2289-2298
[39] Frankewich R P, Hinze W L, Anal. Chem., 1994, 66(7): 944-954
[40] Seronero L C, Laespada M E F, Pav(?)n J L P, Cordero B M, J. Chromatogr. A, 2000, 897:171-176
[41] Materna K, Szymanowski J, J. Colloid and Interface Science, 2002, 255: 195-201
[42] Wang Z L, Zhao F S, Li D T, Colloids and Surfaces A: Physicochem. Eng. Aspects, 2003, 216:207-214
[43] Wu Y C, Huang S D, Anal. Chim. Acta, 1998, 373:197-206
[44] Wu Y C, Huang S D, Analyst, 1998, 123:1535-1539
[45] Revia R L, Makharadze G A, Talanta, 1999, 48:409-413
[46] Tang A N, Jiang D Q, Yah XP, Anal. Chim. Acta, 2004, 507:199-204
[47] Tang A N, Jiang D Q, Jiang Y, Wang S W, Yan X P, J. Chromatogr. A, 2004, 1036:183-188
[48] 曾锋,崔昆燕,分析化学,1996,24(3):372
[49] 唐辉,周发连,罗明标,邹悦,分析试验室,2004,23(1):23-25
[50] Sombra L, Luconi M, Silva M F, Olsina R A, Fernandez L, Analyst, 2001, 126: 1172-1176
[51] 王广健,郭晏仙,冶金分析,1998,18(4):3-6
[52] 王广健,朱瑞涛,分析化学,2000,28(3):385
[53] 汤桂娜,于薇,王保宁,分析化学,1993,21(5):544-546
[54] 曾锋,崔昆燕,路伟,理化检验-化学分册,1997,33(2):57-58
[55] 周之荣,张劲松,中国环境监测,1998,14(6):9-10
[56] 周之荣,费忠明,胡凯,光谱实验室,2000,17(4):425-427
[57] 王玉枝,周毅刚,陈进新,罗明辉,曾鸽鸣,分析试验室,2000,19(6):24-26
[58] 郭亚杰,张建芸,王广健,冶金分析,2001,21(2):4-6
[59] 王广健,解世峰,郭亚杰,尚德库,理化检验-化学分册,2001,37(6):247-249
[60] Silva M F,Fernandez L,Olsina R A,Stacchiola D,Anal.Chim.Acta,1997, 342:229-238
[61] 曾锋,崔昆燕,梁品梅,理化检验-化学分册,1994,30(1):204-205
[62] Silva M F, Fernandez L, Olsina R A, Analyst, 1998, 123: 1803-1807
[63] 邱凤仙,冶金分析,1999,19(6):47-49
[64] 何巧红,朱有瑜,毛雪琴,理化检验-化学分册,1998,34(3):109-110
[65] 周发连,黄晓峰,岩矿测试,1993,12(2):119-121
[66] Laespada M E F, Pav(?)n J L P, Cordero B M, Analyst, 1993, 118:209-212
[67] 曾锋,崔昆燕,分析化学,1995,23(11):1323
[68] 崔昆燕,曾锋,分析试验室,2000,19(5):34-36
[69] Jin G, Kan J Y, Zhu Y R, Lei N, Chen B, Microchem. J., 2000, 64:111-118
[70] 周发连,高艳明,华东地质学院学报,1992,15(2):180-185
[71] 周发连,高艳明,分析化学,1995,23(4):423-425
[72] 曾锋,崔昆燕,应敏,王良清,分析化学,1996,24(6):736
[73] 曾锋,崔昆燕,王良清,理化检验-化学分册,1997,33(1):9-11
[74] Paleologos E K, Koupparis M A, Karayannis M I, Veltsistas P G, Anal. Chem., 2001, 73:4428-4433
[75] Igarashi S, Endo K, Anal. Chim. Acta, 1996, 320:133-138
[76] Paleologos E K, Vlessidis A G; Karayannis M I, Evmiridis N P, Anal. Chim. Acta, 2003, 477:223-231
[77] 杨祥,汤志勇,陈飞,韩丽荣,牛进龙,金泽祥,贵金属,2000,21(2):43-45
[78] 杨祥,马艳芳,王丽,王小强,汤志勇,金泽祥,国外分析仪器,2000,(1):71-73
[79] Pinto C G, Pavon J L P, Cordero B M, Sanchez S G, J. Anal. At. Spectrom., 1996, 11:37-40
[80] Manzoori J L, Karim-Nezhad G; Anal. Sci., 2003, 19:579-583
[81] Nascentes C C, Arruda M A Z, Talanta, 2003, 61:759-768
[82] Manzoori J L, Bavili-Tabrizi A, Microchem. J., 2002, 72:1-7
[83] 陈建荣,林建军,分析试验室,2002,21(5):86-89
[84] 杨祥,陈飞,窦希波,汤志勇,金泽祥,鲁群苟,理化检验-化学分册,2002,38(7):355-356
[85] Giokas D L, Paleologos E K, Veltsistas P G. Karayannis M I, Talanta, 2002, 56: 415-424
[86] Teo K C, Chen J, Analyst, 2001, 126:534-537
[87] Bezerra M A, Cencelcao A L B, Ferreira S L C, Anal. Bioanal. Chem., 2004, 378:798-803
[88] Luconi M O, Silva M F, Olsina R A, Fern(?)ndez L P, Talanta, 2000, 51:123-129
[89] 杨祥,韩鸿印,陈文武,张新华,汤志勇,金泽祥,光谱学与光谱分析,2004,24(3):363-365
[90] Kulichenko S A, Doroshchuk V A, J. Anal. Chem., 2003, 58(6): 524-527
[91] Chen J R, Teo K C, Anal. Chim. Acta, 2001, 434:325-330
[92] Manzoori J L, Bavili-Tabrizi A, Microchim. Acta, 2003, 141:201-207
[93] Oliveros M C C, Blas O J, Pav(?)n J L P, Cordero B M, J. Anal. At. Spectrom., 1998, 13:547-550
[94] Manzoori J L, Bavili-Tabrizi A, Anal. Chim. Acta, 2002, 470:215-221
[95] Silva M A M, Frescura V L A, Curtius A J, J. Anal. At. Spectrom., 1998, 13:1369-1373
[96] Giokas D L, Paleologos E K, Tzouwara-Kamyanni S M, Karayannis M I, J. Anal. At. Spectrom., 2001, 16:521-526
[97] Chen J R, Teo K C, Anal. Chim. Acta, 2001, 450:215-222
[98] B(?)y(?)kbayram A E, Volkan M, Spectrochirn. Acta, Part B, 2000, 55:1073-1080
[99] Borges D L G; Veiga M A M S, Frescura V L A, Welz A, Curtius A J, J. Anal. At. Spectrom., 2003, 18:501-507
[100] Nan J, Jiang Y, Yan X P, J. Anal. At. Spectrom., 2003, 18:946-950
[101] Sombra L L, Luconi M O, Fernandez L P, Olsina R A, Silva M F, Martinez L D, J. Pharm. Biomed. Anal., 2003, 30:1451-1458
[102] Ortega C, Cerutti S, Olsina R A, Silva M F, Martinez L D, Anal. Bioanal. Chem., 2003, 375:270-274
[103] Ortega C, Gomez M R, Olsina R A, Silva M F, Martinez L D, J. Anal. At. Spectrom., 2002, 17:530-533
[104] Wuilloud G M, Wuilloud J C A, Wuilloud R G; Silva M F, Olsina R A, Martinez L D, Yalanta, 2002, 58:619-627
[105] Wuilloud J C A, Wuilloud R G, Silva M F, Olsina R A, Martinez L D, Spectrochim. Acta, Part B, 2002, 57:365-374
[106] Silva M A M, Frescura V L A, Curtius A J, Spectrochim. Acta, Part B,.2001, 56:1941-1949
[107] Silva M A M, Frescura V L A, Curtius A J, Spectrochim. Acta, Part B, 2000, 55:803-813
[108] Templeton D, Ariese F, Comelis R, Pure Appl. Chem., 2000, 72:1453-1462
[109] 周发连,高艳明,分析化学,1992,20(7):806-809
[110] Paleologos E K, Stalikas C D, Tzouwara-Karayanni S M, Pilidis G A, Karayannis M I, J. Anal. At. Spectrom., 2000, 15:287-291
[111] Paleologos E K, Stalikas C D, Karayannis M I, Analyst, 2001, 126:389-393
[112] 朱霞石,江祖成,胡斌,李铭芳,分析化学,2003,31(11):1312-1316
[113] Paleologos E K, Stalikas C D, Tzouwara-Karayanni S M, Karayannis M I, Anal. Chim. Acta, 2001, 436:49-57
[114] Giokas D L, Antelo J, Paleologos E K, Arce F, Karayannis M I, J. Environ. Monit., 2002, 4:505-510
[115] Giokas D L, Paleologos E K, Karayannis M I, Anal. Bioanal. Chem., 2002, 373:237-243
[116] Paleologos E K, Giokas D L, Tzouwara-Karayanni S M, Karayannis M I, Anal. Chim. Acta, 2002, 458:241-248