Optimization of acid digestion conditions on the extraction of fatty acids from stalagmites

Abstract

Lipids in stalagmites have been shown the potential for the paleoclimate reconstruction. However, the low lipid content leads to the difficulty in gaining high resolution lipid record in stalagmites because large mass of samples are required. Previous studies have validated that the acid digestion can improve the yield of lipids, especially fatty acids (FAs) and 3-hydroxy fatty acids (3-OH-FAs). In order to obtain more content of FAs and 3-OH-FAs with limited stalagmite sample weight, we investigate here how the acid digestion conditions (HCl concentration, heating temperature and time duration) could affect the yields of FAs and 3-OH-FAs. Under different concentration of HCl, from 2.0 to 6.0 mol/L, the FAs keep the same step in content variation with 3-OH-FAs, and the highest yields of both two appeared under the 3 mol/L HCl. The content of 3-OH-FAs increases positively with the heating temperature from 80°C to 150°C, while FAs showed the highest content at 130°C. Both of FAs and 3-OH-FAs firstly increased to a high content and then decreased as the heating time duration varies from 1.0 to 4.0 h, with the highest yields of both two being at 3.0 h. Consequently, we suggest the optimized acid digestion condition is under 3 mol/L HCl, heating at 130°C for 3 h and 5 g of each stalagmite sample are sufficient for the lipid analysis.

Keywords

stalagmite / lipids / acid digestion / optimization

References

[1] Blyth A J, Asrat A, Baker A, Gulliver P, Leng M J, Genty D (2007). A new approach to detecting vegetation and land-use change using high-resolution lipid biomarker records in stalagmites. Quaternary Research, 68(3): 314–324

[2] Blyth A J, Baker A, Collins M J, Penkman K E H, Gilmour M A, Moss J S, Genty D, Drysdale R N (2008). Molecular organic matter in speleothems and its potential as an environmental proxy. Quaternary Science Reviews, 27(9–10): 905–921

[3] Blyth A J, Farrimond P, Jones M (2006). An optimised method for the extraction and analysis of lipid biomarkers from stalagmites. Organic Geochemistry, 37(8): 882–890

[4] Dyk M, Kock J, Botha A (1994). Hydroxy long-chain fatty acids in fungi. World Journal of Microbiology and Biotechnology, 10(5): 495–504

[5] Edlund A, Nichols P D, Roffey R, White D C (1985). Extractable and lipopolysaccharide fatty acid and hydroxy acid profiles from Desulfovibrio species. Journal of Lipid Research, 26(8): 982–988

[6] Fairchild I J, Smith, C L, Baker A, Fuller L, Spötl C, Mattey D, McDermott F (2006). Modification and preservation of environmental signals in speleothems. Earth Science Reviews, 75: 105–153

[7] Hellstrom J, McCulloch M, Stone J (1998). A detailed 31000-year record of climate and vegetation change, from the isotope geochemistry of two New Zealand speleothems. Quaternary Research, 50(2): 167–178

[8] Henderson G M (2006). Caving in to new chronologies. Science, 313(5787): 620–622

[9] Hu C, Henderson G M, Huang J, Xie S, Sun Y, Johnson K R (2008). Quantification of Holocene Asian monsoon rainfall from spatially separated cave records. Earth and Planetary Science Letters, 266(3–4): 221–232

[10] Huang X, Cui J, Pu Y, Huang J, Blyth A J (2008). Identifying “free” and “bound” lipid fractions in stalagmite samples: an example from Heshang Cave, southern China. Applied Geochemistry, 23(9): 2589–2595

[11] Kaneda T (1967). Fatty acids in the genus Bacillus I. Iso- and anteiso-fatty acids as characteristic constituents of lipids in 10 species. Journal of Bacteriology, 93(3): 894–903

[12] Keinänen M M, Korhonen L K, Martikainen P J, Vartiainen T, Miettinen I T, Lehtola M J, Nenonen K, Pajunen H, Kontro M H (2003). Gas chromatographic-mass spectrometric detection of 2- and 3-hydroxy fatty acids as methyl esters from soil, sediment and biofilm. Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Science, 783(2): 443–451

[13] Lawrence E R, Chen J, Wasserburg G (1987). ²³⁸U-²³⁴U-²³⁰Th-²³²Th systematics and the precise measurement of time over the past 500000 years. Earth and Planetary Science Letters, 81(2–3): 175–192

[14] Lewis S C, Gagan M K, Ayliffe L K, Zhao J, Hantoro W S, Treble P C, Hellstrom, J C, LeGrande A N, Kelley M, Schmidt G A (2011). High-resolution stalagmite reconstructions of Australian-Indonesian monsoon rainfall variability during Heinrich stadial 3 and Greenland interstadial 4. Earth and Planetary Science Letters, 303(1–2):133–142

[15] Li X, Wang C, Huang J, Hu C, Xie S (2011). Seasonal variation of fatty acids from drip water in Heshang Cave, Central China. Applied Geochemistry, 26(3): 341–347

[16] Mendoza Y A, Gülacar F O, Buchs A (1987). Comparison of extraction techniques for bound carboxylic acids in recent sediments: 2. β-Hydroxyacids. Chemical geology, 62(3–4): 321–330

[17] Mielniczuk Z, Mielniczuk E, Larsson L (1993). Gas chromatography-mass spectrometry methods for analysis of 2- and 3-hydroxylated fatty acids: application for endotoxin measurement. Journal of Microbiological Methods, 17(2): 91–102

[18] Pausata F S R, Battisti D S, Nisancioglu K H, Bitz C M (2011). Chinese stalagmite δ¹⁸O controlled by changes in the Indian monsoon during a simulated Heinrich event. Nature Geoscience, 4(7): 474–480

[19] Szponar B, Larsson L (2001). Use of mass spectrometry for characterising microbial communities in bioaerosols. Annals of Agricultural and Environmental Medicine, 8(2): 111–117

[20] Volkman J K, Barrett S M, Blackburn S I (1999). Fatty acids and hydroxy fatty acids in three species of freshwater eustigmatophytes. Journal of Phycology, 35(5): 1005–1012

[21] Wakeham S G (1999). Monocarboxylic, dicarboxylic and hydroxy acids released by sequential treatments of suspended particles and sediments of the Black Sea. Organic Geochemistry, 30(9): 1059–1074

[22] Wang Y, Liu X, Herzschuh U (2010). Asynchronous evolution of the Indian and East Asian Summer Monsoon indicated by Holocene moisture patterns in monsoonal central Asia. Earth Science Reviews, 103(3–4): 135–153

[23] Wollenweber H, Rietschel E T, Hofstad T, Weintraub A, Lindberg A (1980). Nature type of linkage, quantity and absolute configuration of (3-hydroxy) fatty acids in lipopolysaccharides from bacteroides fragilis NCTC 9343 and related strains. Journal of Bacteriology, 144(3): 898–903

[24] Xie S, Chen F, Wang Z, Wang H, Gu Y, Huang Y (2003). Lipid distributions in loess-paleosol sequences from Northwest China. Organic Geochemistry, 34(8): 1071–1079

[25] Zhao J, Yu K, Feng Y (2009). High-precision ²³⁸U-²³⁴U-²³⁰Th disequilibrium dating of the recent past: a review. Quaternary Geochronology, 4(5): 423–433

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