Determination of trace elements in vegetable oils and biodiesel by atomic spectrometric techniques - A review

Applied Spectroscopy Reviews

Volumn 46, Issue 3, 2011, Pages 175-206

  Lepri, Fábio G ^a   Chaves, Eduardo S ^a   Vieira, Mariana A ^b   Ribeiro, Anderson S ^b   Curtius, Adilson J ^a   De Oliveira, Lígia C C ^c   De Campos, Reinaldo C ^c  

^a FEDERAL UNIVERSITY OF SANTA CATARINA   (Brazil)

^b FEDERAL UNIVERSITY OF PELOTAS   (Brazil)

^c PONTIFICAL CATHOLIC UNIVERSITY OF RIO DE JANEIRO   (Brazil)

Author keywords

atomic spectrometry techniques; biodiesel; Trace elements; vegetable oil

Indexed keywords

ATOMIC SPECTROMETRIC TECHNIQUES; ATOMIC SPECTROMETRY TECHNIQUES; EDIBLE OIL; INDUCTIVELY COUPLED PLASMA-OPTICAL EMISSION SPECTROMETRY; OPTICAL EMISSION SPECTROMETRY; RECENT TRENDS; SAMPLE INTRODUCTION; SAMPLE MANIPULATION; SAMPLE PRETREATMENT; SPECTROMETRIC METHODS; TRACE METAL;

ABSORPTION SPECTROSCOPY; AGRICULTURAL CHEMICALS; ATOMIC ABSORPTION SPECTROMETRY; ATOMIC SPECTROSCOPY; ATOMS; BIODIESEL; FLUORINE; INDUCTIVELY COUPLED PLASMA; LIGHT EMISSION; LUBRICATING OILS; MASS SPECTROMETRY; OPTICAL EMISSION SPECTROSCOPY; PLASMA DIAGNOSTICS; TRACE ANALYSIS; VEGETABLE OILS;

TRACE ELEMENTS;

EID: 79953104169     PISSN: 05704928     EISSN: 1520569X     Source Type: Journal    
DOI: 10.1080/05704928.2010.529628     Document Type: Article

References (107)

1. Balat, M. (2007) Production of biodiesel from vegetable oils: A survey. Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 29: 895-913. (Pubitemid 46933338)
2. Demirbas, A. (2007) Recent developments in biodiesel fuels. Int. J. Green Energ., 4: 15-26. (Pubitemid 46978820)
3. Pinto, A.C., Guarieiro, L.L.N., Rezende, M.J.C., Ribeiro, N.M., Torres, E.A., Lopes, W.A., Pereira, P.A.P., and De Andrade, J.B. (2005) Biodiesel: An overview. J. Braz. Chem. Soc., 16: 1313-1330. (Pubitemid 43104509)
4. Demirbas, A. (2002) Biodiesel from vegetable oils via transesterification in supercritical methanol. Energ. Conservat. Manag., 43: 2349-2356. (Pubitemid 34772396)
5. Ramadhas, A.S., Jayaray, S., andMuraleedharam, C. (2004) Use of vegetable oils as I.C. engine fuels-A review. Renew. Energ., 29: 727-742. (Pubitemid 38003044)
6. Bozbas,K. (2008) Biodiesel as an alternative motor fuel: Production and policies in the European Union. Renew. Sustain. Energ. Rev., 12: 542-552. (Pubitemid 350214539)
7. Knothe, G., Gerpen, J.V., and Krahl, J. (2005) The Biodiesel Handbook. AOCS Books: Champaign, IL.
8. Cordella, C., Moussa, I., Martel, A.C., Sbirrazzuoli, N., and Lizzani-Cuvelier, L. (2002) Recent developments in food characterization and adulteration detection: Technique-oriented perspectives. J. Agric. Food. Chem., 50: 1751-1764. (Pubitemid 34259964)
9. Mittelbach, M. and Schober, S. (2003) The influence of antioxidants on the oxidation stability of biodiesel. J. Am. Oil Chem. Soc., 80: 817-823.
10. Woods,G.D. and Fryer, F.I. (2007) Direct elemental analysis of biodiesel by inductively coupled plasma-mass spectroscopy. Anal. Bioanal. Chem., 389: 753-761. (Pubitemid 47462444)
11. Garrido, M.D., Frias, I., Diaz, C., and Hardisson, A. (1994) Concentrations of metals in vegetable edible oils. Food Chem., 50: 237-243. (Pubitemid 24156981)
12. U.S. Department of Energy. (2004) Biodiesel Handling and Use Guidelines. National Renewable Energy Laboratory. DOE/GO-102004-1999.
13. Kowalewska, Z., Izgi, B., Saracogulo, S., and Gucer, S. (2005) Application of liquid-liquid extraction and adsorption on activated carbon of the determination of different forms of metals present in edible oils. Chem. Anal., 50: 1007-1019. (Pubitemid 43128444)
14. Pinto, P.C.A.G., Sariava, M.L.M.F.S., and Lima, J.L.F.C. (2006) A flow sampling strategy for the analysis of oil samples without pre-treatment in a sequential injection analysis system. Anal. Chim. Acta, 555: 377-383. (Pubitemid 41828172)
15. Deck, R.E. and Kaiser, K.K. (1970) Analytical method for determining copper in edible shortenings and oils. J. Am. Oil Chem. Soc., 47: 126-128.
16. Lo Coco, F., Ceccon, L., Ciraolo, L., and Novelli, V. (2003) Determination of cadmium(II) and zinc(II) in olive oils by derivative potentiometric stripping analysis. Food Contr., 14: 55-59. (Pubitemid 35469309)
17. Cypriano, J.C., Matos, M.A.C., and Matos, R.C. (2008) Ultrasound-assisted treatment of palm oil samples for the determination of copper and lead by stripping chronopotentiometry. Microchem. J., 90: 26-30.
18. Amini, M.K., Momeni-Isfahani, T., Khorasani, J.H., and Pourhossein, M. (2004) Development of an optical chemical sensor based on 2-(5-bromo-2- pyridylazo)-5-(diethylamino)phenol in Nafion for determination of nickel ion. Talanta, 63: 713-720.
19. Prasad,N.B.L., Reddy, K.H., and Reddy, T.S. (2003) Analytical properties of 2-acetylthiophene- 4-phenyl-3-thiosemicarbazone spectrophotometry determination of copper(II) in edible oils and seeds. Indian J. Chem. Inorg. Phys. Theor. Anal. Chem., 42: 112-115.
20. Obi, A.L., Jonah, S.A., and Umar, I. (2001) Determination of trace elements in some Nigerian vegetable based oils by neutron activation analysis. J. Radioanal. Nucl. Chem. 249: 669-671. (Pubitemid 32800059)
21. Buldina, P.L., Ferrib, D., and Sharmac, J.L. (1997) Determination of some inorganic species in edible vegetable oils and fats by ion chromatography. J. Chrom., 789: 549-555.
22. Black, L.T. (1975) Comparison of 3 atomic absorption techniques for determining metals in soybean oil. J. Am. Oil Chem. Soc., 52: 88-91.
23. Sneddon, J., Hardaway, C., Bobbadi, K.K., and Reddy, A.K. (2006) Sample preparation of solid samples for metal determination by atomic spectroscopy-An overview and selected recent applications. Appl. Spectros. Rev., 41 (1): 1-14. (Pubitemid 43090655)
24. Korn,M.G.A., Mort, E.S.B., Dos Santos, D.C.M.B., Castro, J.T., Barbosa, J.T.P., Teixeira, A.P., Fernandes, A.P., Welz, B., Dos Santos, W.P.C., Dos Santos, E.B.G.N., and Korn, M. (2008) Sample preparation for the determination of metals in food samples using spectroanalytical methods-A review. Appl. Spectros. Rev., 43 (2): 67-92.
25. Bizzi, C.A., Flores, E.M.M., Picoloto, R.S., Barin, J.S., and Nobrega, J.A. (2010) Microwaveassisted digestion in closed vessels: Effect of pressurization with oxygen on digestion process with diluted nitric acid. Anal. Methods, 2 (6): 734-738.
26. Duyck, C., Miekeley, N., Da Silveira, C.L.P., Auçelio, R.Q., Campos, R.C., Grinberg, P., and Brandão, G.P. (2007) The determination of trace elements in crude oil and its heavy fractions by atomic spectrometry. Spectrochim. Acta, 62B (9): 939-951. (Pubitemid 47407799)
27. Lan, G., Ming-Yong, X., Ai-Ping, Y., and Jian-Yun, X. (2007) Simultaneous analysis of multielements in vegetation oils by inductively coupled plasma atomic emission spectrometry. Spectroscopy and Spectral Analysis, 27 (11): 2345-2348.
28. Zhen-Lin, W., Lin, S., Yu-Kui, R., and Chuan-Zhen, J. (2008) Application of ICP-MS to the direct detection of 22 elements in transgenic soybean oil. Spectroscopy and Spectral Analysis, 28 (6): 1398-1399.
29. Saleh, M.I., Murray, R.S., and Chin, C. N. (1988) Ashing techniques in the determination of iron and copper in palm oil. J. Am. Oil Chem. Soc., 65: 1767-1770.
30. Sun, H.J. (1989) A rapid method for the determination of trace Cu and Fe in edible salad oil by graphite furnace atomic absorption spectroscopy. J. Am. Oil Chem. Soc., 66: 549-552.
31. Kolasa, D., Arndt, B., Jedras, C., and Zorawska, K. (1999) Determination of copper by atomic absorption spectrometry in studying copper migration from food-packaging plastic materials. Polimery, 44: 614-617. (Pubitemid 129652643)
32. Carbonell, V., Mauri, A.R., Salvador, A., and De la Guardia, M. (1991) Direct determination of copper and iron in edible oils using flow-injection flame atomic absorption spectrometry. JAAS: Journal of Analytical Atomic Spectrometry, 6: 581-584.
33. Kubrakova, I.V., Kudinova, T.F., Stavnivenk, E.B., and Kuzmin, N.M. (1997) Microwave radiation as a factor intensifying sample preparation: Analysis of samples with an organic matrix. J. Anal. Chem., 52 (6): 522-527. (Pubitemid 127725965)
34. Burguera, M. and Burguera, J.L. (1996) Microwave sample pretreatment in analytical systems. A review. Quim. Anal., 15 (2): 112-122. (Pubitemid 126107247)
35. Allen, L.B., Siitonen, P.H., and Thompson, H.C. (1998) Determination of copper, lead and nickel in edible oils by plasma and furnace atomic spectroscopies. J. Am. Oil Chem. Soc., 75: 477-481. (Pubitemid 128562381)
36. Cindric, I.J., Zeiner, M., and Steffan, I. (2007) Trace elemental characterization of edible oils by ICP-AES and GF AAS. Microchem. J., 85: 136-139.
37. Gonzálvez, A., Ghanjaoui, M.E., El Rhazi, M., and De la Guardia, M. (2010) Inductively coupled plasma optical emission spectroscopy determination of trace element composition of argan oil. Food Sci. Tech. Int., 16: 65-71.
38. Juranovic, I.,Breinhoelder, P., and Steffan, I. (2003) Determination of trace elements in pumpkin seed oils and pumpkin seeds by ICP-AES. JAAS: Journal of Analytical Atomic Spectrometry, 18: 54-58.
39. Benincasa, C., Lewis, J., Perri, E., Sindona, G., and Tagarelli, A. (2007) Determination of trace element in Italian virgin olive oils and their characterization according to geographical origin by statistical analysis. Anal. Chim. Acta, 585: 366-370. (Pubitemid 46188426)
40. Mendil, D., Oluozlu, O.D., Tuzen, M., and Soylak, M. (2009) Investigation of the levels of some element in edible oil samples produced in Turkey by atomic absorption spectrometry. J. Hazard. Mater., 165: 724-728.
41. Zeiner, M., Steffan, I., and Cindric, I.J. (2005) Determination of trace elements in olive oil by ICP-AES and ETA-AAS: A pilot study on the geographical characterization. Microchem. J., 81: 171-176. (Pubitemid 41058995)
42. Bakkali, K., Ballesteros, E., Souhail, B., and Martos, N.R. (2009) Determination of metal traces in vegetable oils from Spain andMorocco by graphite chamber atomic absorption spectroscopy following microwave digestion. Grasas y Aceites, 60: 490-497.
43. Ansari, R., Kazi, T.G., Jamali, M.K., Arain, M.B., Wagan, M.D., Jalbani, N., Afridi, H.I., and Shah, A.Q. (2009) Variation in accumulation of heavy metals in different verities of sunflower seed oil with the aid of multivariate technique. Food Chem., 115: 318-323.
44. Llorent-Martínez, E.J., Ortega-Barrales, P., Fernández-de çordova, M.L., and Ruiz-Medina, A. (2010) Analysis of the legislated metals in different categories of olive and olive-pomace oils. Food Control. In Press. doi:10.1016/j.foodcont.2010.07.002
45. Joebstl, D., Bandoniene, D., Meisel, T., and Chatzistathis, S. (2010) Identification of the geographic origin of pumpkin seed oil by the use of rare earth elements and discriminant analysis. Food Chem., 123 (4): 1303-1309.
46. Reyes, M.N.M. and Campos, R.C. (2006) Determination of copper and nickel in vegetable oils by direct sampling graphite furnace atomic absorption spectrometry. Talanta, 70: 929-932. (Pubitemid 44693594)
47. De Oliveira, A.P., Villa, R.D., Antunes, K.C.P., De Magalhães, A., and Castro e Silva, E. (2009) Determination of sodium in biodiesel by flame atomic emission spectrometry using dry decomposition for the sample preparation. Fuel, 88: 764-766.
48. Cheng, L.J., Zheng, L.Y., Zhao, D.S., and Sun, H.W. (2004) Determination of trace copper and zinc in vegetable oils by derivative flame atomic absorption spectrometry combined with flow-injection technique. Spectroscopy and Spectral Analysis, 24: 1013-1015.
49. Zalts, A., Troccoli, O.E., and Possidoni de Albirati, J.F. (1986) Determination of microamounts of Cu and Fe in edible oils by atomic absorption spectroscopy. Anales de La Asociacion Argentina, 74: 55-60.
50. Sun, J.M., Lin, L.X., and Sun, H.W. (2003) Determination of lead and zinc in oil plant seeds by F AAS with micro injection and derivative signal processing. Spectroscopy and Spectral Analysis, 23 (6): 1197-1198.
51. Fischer, J.L. and Rademeyer, C.J. (1994) Direct determination of metals in oils by inductively coupled plasma atomic emission spectrometry using high temperature nebulization. JAAS: Journal of Analytical Atomic Spectrometry, 9: 623-628.
52. Martin-Polvillo, M., Albi, T., and Guinda, A. (1994) Determination of trace elements in edible vegetable oils by atomic absorption spectrophotometry. J. Am. Oil Chem. Soc., 71: 347-353.
53. Zakharov, Y.A., Motyguilin, E.K., and Gilḿutdinov, A.K. (2000) Direct determination of phosphorus in vegetable oils by electrothermal atomic absorption spectrometry. J. Anal. Chem., 55 (7): 723-727.
54. Lyra, F.H., Carneiro, M.T.W.D., Brandão, G.P., Pessoa, H.M., and Castro, E.V.R. (2009) Direct determination of phosphorus in biodiesel samples by graphite furnace atomic absorption spectrometry using a solid sampling accessory. JAAS: Journal of Analytical Atomic Spectrometry, 24: 1262-1266.
55. BS EN 14107. (2003) Fat and Oil Derivatives-Fatty Acid Methyl Esters (FAME), Determination of Phosphorus Content by Inductively Coupled Plasma (ICP) Emission Spectrometry.
56. Karadjova, I., Zachariadis, G., Boskou, G., and Stratis, J. (1998) Electrothermal atomic absorption spectrometric determination of aluminum, cadmium, chromium, copper, iron, manganese, nickel and lead in olive oil. JAAS: Journal of Analytical Atomic Spectrometry, 13: 201-204. (Pubitemid 128593928)
57. Bozhanov, S.R. and Karadjova, I.B. (2008) Determination of trace metals in Bulgarian lavender oil by electrothermal atomic absorption spectrometry. J. Essent. Oil Res., 20: 549-555.
58. Chen, S.S., Cheng, C.C., and Chou, S.S. (2003) Determination of arsenic in edible oils by direct graphite furnace atomic absorption spectrometry. J. Food Drug Anal., 11: 214-219.
59. Chen, S.S., Chen, C.M., Cheng, C.C., and Chou, S.S. (1999) Determination of copper in edible oils by direct graphite furnace atomic absorption spectrometry. J. Food Drug Anal., 7: 207-214.
60. Canário, C.M. and Katskov, D.M. (2005) Direct determination of Cd and Pb in edible oils by atomic absorption spectrometry with transverse heated filter atomizer. JAAS: Journal of Analytical Atomic Spectrometry, 20: 1386-1388. (Pubitemid 41784458)
61. Marfil, R., Cabrera-Vique, C., Giménez, R., Bouzas, P.R., Martinez, O., and Sánchez, J.A. (2008) Metal content and physicochemical parameters used as quality criteria in virgin argan oil: Influence of the extraction method. J. Agr. Food Chem., 56: 7279-7284.
62. Dijkstra, A.J. and Meert, D. (1982) Determination of trace elements in oils by plasma emission spectroscopy. J. Am. Oil Chem. Soc., 59: 199-204. (Pubitemid 12518867)
63. Kassa, P. and Bogdanor, J.M. (1987) Phosphorus and trace metal analysis by ICP. J. Am. Oil Chem. Soc., 64 (5): 656.
64. Von Piechowski, K., Massop, K., Pyrlik, H., and Slickers, K. (1991) Analysis of trace-elements in oil and fat processing by ICP-AES (inductively coupled plasma emission-spectrometry). Alimenta, 30 (4): 63-67.
65. Monteiro, M.R., Ambrozin, A.R.P., Lião, L.M., and Ferreira, A.G. (2008) Critical review on analytical methods for biodiesel characterization. Talanta, 77: 593-605.
66. ASTM D5863-00a. (2005) Standard TestMethods for Determination of Nickel, Vanadium, Iron, and Sodium in Crude Oils and Residual Fuels by Flame Atomic Absorption Spectrometry.
67. BS EN 14109. (2003) Fat and Oil Derivatives-Fatty Acid Methyl Esters (FAME), Determination of Potassium Content by Atomic Absorption Spectrometry.
68. BS EN 14108. (2003) Fat and Oil Derivatives-Fatty Acid Methyl Esters (FAME), Determination of Sodium Content by Atomic Absorption Spectrometry.
69. ABNT NBR 15554:2008. Produtos derivados de óleos e gorduras. Ésteres metílicos/etílicos de ácidos graxos. Determinação do teor de sódio por espectrometria de absorção atǒmica. Fat oil and derivatives. Fatty acid methyl esters. Determination of the sodium, potassium, calcium and magnesium contents by atomic absorption spectrometry.
70. ABNT NBR 15555:2008. Produtos derivados de óleos e gorduras. Ésteres metílicos/etílicos de ácidos graxos. Determinação do teor de potássio por espectrometria de absorção atǒmica. Fat oil and derivatives. Fatty acid methyl esters. Determination of the sodium, potassium, calcium and magnesium contents by atomic absorption spectrometry.
71. ABNT NBR 15556:2008. Produtos derivados de óleos e gorduras. Ésteres metílicos/etílicos de ácidos graxos. Determinação do teor de sódio, potássio, çalcio e magnésio por espectrometria de absorção atǒmica. Fat oil and derivatives. Fatty acid methyl esters. Determination of the sodium, potassium, calcium and magnesium contents by atomic absorption spectrometry.
72. DIN EN 14538. (2006) Fat and Oil Derivatives-Fatty Acid Methyl Esters (FAME), Determination of Ca, K, Mg and Na Content by Optical Emission Spectral Analysis with Inductively Coupled Plasma (ICP OES).
73. Edlund, M., Visser, H., and Heitland, P. (2002) Analysis of biodiesel by argon-oxygen mixedgas inductively coupled plasma optical emission spectrometry. JAAS: Journal of Analytical Atomic Spectrometry, 17: 232-235. (Pubitemid 34476531)
74. Santos, E.J., Herrmann, A.B., Chaves, E.S., Vechiatto,W.W.D., Schoemberger, A.C., Frescura, V.L.A., and Curtius, A.J. (2007) Simultaneous determination of Ca, P, Mg,KandNa in biodiesel by axial view inductively coupled plasma optical emission spectrometry with internal standardization after multivariate optimization. JAAS: Journal of Analytical Atomic Spectrometry, 22: 1300-1303. (Pubitemid 47519774)
75. Pelizzeti, E. and Pramauro, E. (1985) Analytical applications of organized molecular assemblies. Anal. Chim. Acta, 169: 1-29.
76. Benzo, Z., Zoltan, T., Murillo, M., Quintal, M., Salas, J., Marcano, E., and Gomez, C. (2006) Determination of trace manganese and Ni in neem oil by ETA-AAS with emulsion sample introduction. J. Am. Oil Chem. Soc., 83(5): 401-405. (Pubitemid 43966358)
77. Jimenez, M.S., Lopez, A., and Castillo, J.R. (2002) Automatic emulsion formation as a sample introduction system for the GF AAS determination of iron in edible and mineral oils. Atom. Spectros., 23(6): 183-189.
78. De Souza, R.M., Mathias, B.M., da Silveira, C.L.P., and Auçelio, R.Q. (2005) Inductively coupled plasma optical emission spectrometry for trace multi-element determination in vegetable oils, margarine and butter after stabilization with propan-1-ol and water. Spectrochim. Acta, 60B: 711-715. (Pubitemid 40743839)
79. Murillo, M., Benzo, Z., Marcano, E., Gomez, C., Garaboto, A., and Marin, C. (1999) Determination of copper, iron and nickel in edible oils using emulsified solutions by ICP-AES. JAAS: Journal of Analytical Atomic Spectrometry, 14: 815-820.
80. Benzo, Z., Murillo, M., Marcano, E., Gomez, C., Garaboto, A., and Espinoza, A. (2000) Determination of phosphorus in edible oils by inductively coupled plasma-atomic emission spectrometry and oil-in-water emulsion of sample introduction. J. Am. Oil Chem. Soc., 77: 997-1000.
81. Ibrahim, H. (1991) Determination of lead in frying oils by direct-current plasma atomic emission-spectrometry. J. Am. Oil Chem. Soc., 68: 678-679. (Pubitemid 21722958)
82. Anthemidis, A., Arvanitidis, V., and Stratis, J.A. (2005) On-line emulsion formation and multielement analysis of edible oils by inductively coupled plasma atomic emission spectrometry. Anal. Chim. Acta, 537: 271-278.
83. Chang, Y.T. and Jiang, S.J. (2008) Determination of As, Cd and Hg in emulsified vegetable oil by flow injection chemical vapor generation inductively coupled plasma mass spectrometry. JAAS: Journal of Analytical Atomic Spectrometry, 23: 140-144.
84. Jimenez, M.S., Velarte, R., Gomez, M.T., and Castillo, J.R. (2004) Multielement determination using on-line emulsion formation and ICP-MS/FAAS for the characterization of virgin olive oils by principal component analysis. Atom. Spectros., 25: 1-12.
85. Jiménez, M.S., Velarte, R., and Castilho, J.R. (2003) On-line emulsions of olive oil samples and ICP-MS multi-elemental determination. JAAS: Journal of Analytical Atomic Spectrometry, 18: 1154-1162.
86. Castillo, J.R., Jimenez, M.S., and Ebdon, L. (1999) Semiquantitative simultaneous determination of metal in olive oil using direct emulsion nebulization. JAAS: Journal of Analytical Atomic Spectrometry, 14: 1515-1518.
87. Huang, S.J. and Jiang, S.J. (2001) Determination of Zn, Cd and Pb in vegetable oil by electrothermal vaporization inductively coupled plasma mass spectrometry. JAAS: Journal of Analytical Atomic Spectrometry, 16: 664-668.
88. Vieira, M.A., Oliveira, L.C.C., Gonçalves, R.A., Souza, V., and Campos, R.C. (2009) Determination of As in vegetable oil and biodiesel by graphite furnace atomic absorption spectrometry. Energ. Fuel., 23: 5942-5946.
89. De Jesus, A., Silva, M.M., and Vale,M.G.R. (2008) The use of microemulsion for determination of sodium and potassium in biodiesel by flame atomic absorption spectrometry. Talanta, 74: 1378-1384.
90. De Jesus, A., Zmozinski, A.V., and Barbará, J.A. (2010) Determination of calcium and magnesium in biodiesel by flame atomic absorption spectrometry using microemulsions as sample preparation. Energ. Fuel., 24: 2109-2112.
91. Chaves, E.S., Saint'Pierre, T.D., Santos, E.J., Tormen, L., Frescura, V.L.A., and Curtius, A.J. (2008) Determination of Na and K in biodiesel by flame atomic emission spectrometry and microemulsion sample preparation. J. Braz. Chem. Soc., 19: 856-861.
92. De Souza, R.M., Leocadio, L.G., and Silveira, C.L.P. (2008) ICP OES simultaneous determination of Ca, Cu, Fe, Mg, Mn, Na, and P in biodiesel by axial and radial inductively coupled plasma-optical emission spectrometry. Anal. Lett., 41: 1614-1621.
93. Chaves, E.S., Lepri, F.G., Silva, J.S.A., Quadros, D.P.C., Saint'Pierre, T.D., and Curtius, A.J. (2008) Determination of Co, Cu, Fe, Mn, Ni and V in diesel and biodiesel samples by ETVICP- MS. J. Environ. Monit., 10: 1211-1216.
94. Silva, J.A.S., Chaves, E.S., Santos, E.J., Saint'Pierre, T.D., Frescura, V.L.A., and Curtius, A.J. (2010) Calibration techniques and modifiers for the determination of Cd, Pb and Tl in biodiesel as microemulsion by graphite furnace atomic absorption spectrometry. J. Braz. Chem. Soc., 21: 620-626.
95. Amais, R.S., Garcia, E.E., Monteiro, M.R., Nogueira, A.R.A., and Nóbrega, J.A. (2010) Direct analysis of biodiesel microemulsions using an inductively coupled plasma mass spectrometry. Microchem. J., 96: 146-150.
96. Aranda, R.P., Pacheco, H.P., Olsina, A.R., Martinez, D.L., and Gil, A.R. (2009) Total and inorganic mercury determination in biodiesel by emulsion sample introduction and FI-CVAFS after multivariate optimization. JAAS: Journal of Analytical Atomic Spectrometry, 24: 1441-1445.
97. Lobo, F.A., Goveia, D., De Oliveira, A.P., Pereira-Filho, E.R., Fraceto, L.F., Filho, N.L.D., and Rosa, A.H. (2009) Comparison of the univariate and multivariate methods in the optimization of experimental conditions for determining Cu, Pb, Ni and Cd in biodiesel by GF AAS. Fuel, 88: 1907-1914.
98. Lyra, H.F., Carneiro, D.W.T.M., Brandão, P.G., Pessoa, M.H., and Castro, V.E. (2010) Determination of Na, K, Ca and Mg in biodiesel samples by flame atomic absorption spectrometry (F AAS) using microemulsion as sample preparation. Microchem. J., 96: 180-185.
99. Luque de Castro, M.D. and Priego-Capote, F. (2007) Ultrasound-assisted preparation of liquid samples. Talanta, 72: 321-334. (Pubitemid 46550612)
100. Abe, Y., Fujiura, K., Togawa, N., Morita, H., and Shimomura, S. (1993) Simultaneous multielement analysis of so-called health foods by inductively coupled plasma atomic emission spectroscopy. Jpn. J. Toxicol. Environ. Health, 39 (4): 356-367. (Pubitemid 23288061)
101. Ansari, R., Kazi, T.G., Jamali, M.K., Arain, M.B., Sherazi, S.T., Jalbani, N., and Afridi, H.I. (2008) Improved extraction method for the determination of iron, copper, and nickel in new varieties of sunflower oil by atomic absorption spectroscopy. J. Am. Oil Chem. Soc., 91: 400-407. (Pubitemid 351667411)
102. Anwar, F., Kazi, T.G., Saleem, R., and Bhanger, M.I. (2004) Rapid determination of some trace metals in several oils and fats. Grasas y Aceites, 55: 160-168. (Pubitemid 40360651)
103. De Leonardis, A., Macciola, V., and De Felice, M. (2000) Copper and iron determination in edible vegetable oils by graphite furnace atomic absorption spectrometry after extraction with diluted nitric acid. Int. J. Food Sci. Tech., 35: 371-375.
104. Bati, B. and Cesur, H. (2002) Determination of copper in edible oils by atomic absorption spectrometry after lead piperazinedithiocarbamate solid-phase extraction and potassium cyanide back-extraction. Anal. Sci., 18: 1273-1274.
105. Asci, M.Y., Efendioglu, A., and Bati, B. (2008) Solid-phase extraction of cadmium in edible oils using zinc piperazinedithiocarbamate and its determination by flame atomic absorption spectrometry. Turk. J. Chem., 32: 431-440.
106. Ooms, R. and Pee, W.V. (1983) Determination of trace-metal content in corn-oil by atomicabsorption spectroscopy. J. Am. Oil Chem. Soc., 60: 957-960. (Pubitemid 13542840)
107. Pehlivan, E., Arslan, G., Gode, F., Altun, T., and Ozcan, M.M. (2008) Determination of some inorganic metals in edible vegetable oils by inductively coupled plasma atomic emission spectroscopy (ICP-AES). Grasas y Aceites, 59: 239-244.