Comparison of smoking-related DNA methylation between newborns from prenatal exposure and adults from personal smoking
Sikdar, Sinjini ; Joehanes, Roby ; Joubert, Bonnie R. ; Xu, Cheng Jian ; Vives-Usano, Marta ; Rezwan, Faisal I. ; Felix, Janine F. ; Ward, James M. ; Guan, Weihua ; Richmond, Rebecca C. ; Brody, Jennifer A. ; Küpers, Leanne K. ; Baïz, Nour ; Håberg, Siri E. ; Smith, Jennifer A. ; Reese, Sarah E. ; Aslibekyan, Stella ; Hoyo, Cathrine ; Dhingra, Radhika ; Markunas, Christina A. ; Xu, Tao ; Reynolds, Lindsay M. ; Just, Allan C. ; Mandaviya, Pooja R. ; Ghantous, Akram ; Bennett, Brian D. ; Wang, Tianyuan ; Consortium, The Bios ; Bakulski, Kelly M. ; Melen, Erik ; Zhao, Shanshan ; Jin, Jianping ; Herceg, Zdenko ; Meurs, Joyce Van; Taylor, Jack A. ; Baccarelli, Andrea A. ; Murphy, Susan K. ; Liu, Yongmei ; Munthe-Kaas, Monica Cheng ; Deary, Ian J. ; Nystad, Wenche ; Waldenberger, Melanie ; Annesi-Maesano, Isabella ; Conneely, Karen ; Jaddoe, Vincent W.V. ; Arnett, Donna ; Snieder, Harold ; Kardia, Sharon L.R. ; Relton, Caroline L. ; Ong, Ken K. ; Ewart, Susan ; Moreno-Macias, Hortensia ; Romieu, Isabelle ; Sotoodehnia, Nona ; Fornage, Myriam ; Motsinger-Reif, Alison ; Koppelman, Gerard H. ; Bustamante, Mariona ; Levy, Daniel ; London, Stephanie J. - \ 2019
Epigenomics 11 (2019)13. - ISSN 1750-1911 - p. 1487 - 1500.
cigarette smoking - epigenetics - infant - maternal exposure - methylation
Aim: Cigarette smoking influences DNA methylation genome wide, in newborns from pregnancy exposure and in adults from personal smoking. Whether a unique methylation signature exists for in utero exposure in newborns is unknown. Materials & methods: We separately meta-analyzed newborn blood DNA methylation (assessed using Illumina450k Beadchip), in relation to sustained maternal smoking during pregnancy (9 cohorts, 5648 newborns, 897 exposed) and adult blood methylation and personal smoking (16 cohorts, 15907 participants, 2433 current smokers). Results & conclusion: Comparing meta-analyses, we identified numerous signatures specific to newborns along with many shared between newborns and adults. Unique smoking-associated genes in newborns were enriched in xenobiotic metabolism pathways. Our findings may provide insights into specific health impacts of prenatal exposure on offspring.
Structural features and water holding capacities of pressed potato fibre polysaccharides
Ramasamy, U. ; Kabel, M.A. ; Schols, H.A. ; Gruppen, H. - \ 2013
Carbohydrate Polymers 93 (2013)2. - ISSN 0144-8617 - p. 589 - 596.
cell-wall material - sugar-beet pulp - solanum-tuberosum - nonstarch polysaccharides - aspergillus-aculeatus - nmr characterization - purification - xyloglucan - methylation - conversion
Pressed potato fibre (PPF) has a high water holding capacity (WHC) affecting its processing as an animal feed. The aim of this study was to characterize cell wall polysaccharides (CWPs) in PPF and investigate their WHC. This was done via sequential extractions. Half of all CWPs were recovered in the hot buffer soluble solids extract as pectins (uronic acid and rhamnose) and galactans wherein most pectins (76%) from PPF were water soluble. Most likely, the network of CWPs is loosened during processing of potatoes. PPF showed a WHC of 7.4 expressed as the amount of water held per g of dry matter (mL/g). Reconstituting hot buffer soluble solids with buffer insoluble solids in water gave a WHC comparable to that of PPF. Removal of alkali soluble solids, which mainly comprised xyloglucans, lowered the WHC of the final residue. The results indicated that interactions between CWPs could affect the WHC of PPF.
Transgenerational Effects of Stress Exposure on Offspring Phenotypes in Apomictic Dandelion
Verhoeven, K.J.F. ; Gurp, T.P. van - \ 2012
PLoS ONE 7 (2012)6. - ISSN 1932-6203
arabidopsis-thaliana - trichome density - mimulus-guttatus - plants - responses - methylation - plasticity - herbivory - consequences - inheritance
Heritable epigenetic modulation of gene expression is a candidate mechanism to explain parental environmental effects on offspring phenotypes, but current evidence for environment-induced epigenetic changes that persist in offspring generations is scarce. In apomictic dandelions, exposure to various stresses was previously shown to heritably alter DNA methylation patterns. In this study we explore whether these induced changes are accompanied by heritable effects on offspring phenotypes. We observed effects of parental jasmonic acid treatment on offspring specific leaf area and on offspring interaction with a generalist herbivore; and of parental nutrient stress on offspring root-shoot biomass ratio, tissue P-content and leaf morphology. Some of the effects appeared to enhance offspring ability to cope with the same stresses that their parents experienced. Effects differed between apomictic genotypes and were not always consistently observed between different experiments, especially in the case of parental nutrient stress. While this context-dependency of the effects remains to be further clarified, the total set of results provides evidence for the existence of transgenerational effects in apomictic dandelions. Zebularine treatment affected the within-generation response to nutrient stress, pointing at a role of DNA methylation in phenotypic plasticity to nutrient environments. This study shows that stress exposure in apomictic dandelions can cause transgenerational phenotypic effects, in addition to previously demonstrated transgenerational DNA methylation effects.
Single-tube linear DNA amplification for genome-wide studies using a few thousand cells
Shankaranarayanan, P. ; Mendoza-Parra, M.A. ; Gool, W. van; Trindade, L.M. ; Gronemeyer, H. - \ 2012
Nature protocols 7 (2012)2. - ISSN 1754-2189 - p. 328 - 339.
t7 rna-polymerase - chip-seq - displacement amplification - limited numbers - chromatin - methylation - challenges - principles - samples - domain
Linear amplification of DNA (LinDA) by T7 polymerase is a versatile and robust method for generating sufficient amounts of DNA for genome-wide studies with minute amounts of cells. LinDA can be coupled to a great number of global profiling technologies. Indeed, chromatin immunoprecipitation coupled to massive parallel sequencing (ChIP-seq) has been achieved for transcription factors and epigenetic modification of chromatin histones with 1,000 to 5,000 cells. LinDA largely simplifies reChIP-seq experiments to monitor co-binding at chromatin target sites. The single-tube design of LinDA is ideal for handling ultrasmall amounts of DNA (
A maternal dietary pattern characterised by fish and seafood in association with the risk of congenital heart defects in the offspring
Obermann-Borst, S.A. ; Vujkovic, M. ; Vries, J.H.M. de; Wildhagen, M.F. ; Looman, C.W. ; Jonge, R. de; Steegers, E.A.P. ; Steegers-Theunissen, R.P.M. - \ 2011
BJOG : an international journal of obstetrics and gynaecology 118 (2011)10. - ISSN 1470-0328 - p. 1205 - 1215.
folic-acid supplements - neural-tube defects - nutritional-status - gene-expression - energy-intake - homocysteine - methylation - pregnancy - methionine - period
Objective To identify maternal dietary patterns related to biomarkers of methylation and to investigate associations between these dietary patterns and the risk of congenital heart defects (CHDs) in the offspring. Design Case–control study. Setting Western part of the Netherlands, 2003–08. Population One hundred and seventy-nine mothers of children with CHD and 231 mothers of children without a congenital malformation. Methods Food intake was obtained by food frequency questionnaires. The reduced rank regression method was used to identify dietary patterns related to the biomarker concentrations of methylation in blood. Main outcome measures Dietary patterns, vitamin B and homocysteine concentrations, biomarkers of methylation (S-adenosylmethionine [SAM] and S-adenosylhomocysteine [SAH]) and the risk of CHD estimated by odds ratios and 95% confidence intervals. Results The one-carbon-poor dietary pattern, comprising a high intake of snacks, sugar-rich products and beverages, was associated with SAH (ß = 0.92, P <0.001). The one-carbon-rich dietary pattern with high fish and seafood intake was associated with SAM (ß = 0.44, P <0.001) and inversely with SAH (ß = -0.08, P <0.001). Strong adherence to this dietary pattern resulted in higher serum (P <0.05) and red blood cell (P <0.01) folate and a reduced risk of CHD in offspring: odds ratio, 0.3 (95% confidence interval, 0.2–0.6). Conclusions The one-carbon-rich dietary pattern, characterised by the high intake of fish and seafood, is associated with a reduced risk of CHD. This finding warrants further investigation in a randomised intervention trial.
BrFLC2 (flowering locus C) as a candidate gene for a vernalization response QTL in Brassica rapa
Jianjun Zhao, Jianjun ; Kulkarni, V. ; Liu, Nini ; Pino del Carpio, D. ; Bonnema, A.B. - \ 2010
Journal of Experimental Botany 61 (2010)6. - ISSN 0022-0957 - p. 1817 - 1825.
quantitative trait loci - arabidopsis-thaliana - flc homologs - time genes - expression - plants - methylation - epigenetics - mechanisms - repressor
Flowering time is an important agronomic trait, and wide variation exists among Brassica rapa. In Arabidopsis, FLOWERING LOCUS C (FLC) plays an important role in modulating flowering time and the response to vernalization. Brassica rapa contains several paralogues of FLC at syntenic regions. BrFLC2 maps under a major flowering time and vernalization response quantitative trait locus (QTL) at the top of A02. Here the effects of vernalization on flowering time in a double haploid (DH) population and on BrFLC2 expression in selected lines of a DH population in B. rapa are descibed. The effect of the major flowering time QTL on the top of A02 where BrFLC2 maps clearly decreases upon vernalization, which points to a role for BrFLC2 underlying the QTL. In all developmental stages and tissues (seedlings, cotyledons, and leaves), BrFLC2 transcript levels are higher in late flowering pools of DH lines than in pools of early flowering DH lines. BrFLC2 expression diminished after different durations of seedling vernalization in both early and late DH lines. The reduction of BrFLC2 expression upon seedling vernalization of both early and late flowering DH lines was strongest at the seedling stage and diminished in subsequent growth stages, which suggests that the commitment to flowering is already set at very early developmental stages. Taken together, these data support the hypothesis that BrFLC2 is a candidate gene for the flowering time and vernalization response QTL in B. rapa
Chromatin immunoprecipitation (ChIP) of plant transcription factors followed by sequencing (ChIP-SEQ) or hybridization to whole genome arrays (ChIP-CHIP)
Kaufmann, K. ; Muiño, J.M. ; Østerås, M. ; Farinelli, L. ; Krajewski, P. ; Angenent, G.C. - \ 2010
Nature protocols 5 (2010)3. - ISSN 1754-2189 - p. 457 - 472.
cross-linking - arabidopsis-thaliana - wide analysis - dna - protein - binding - genes - identification - association - methylation
Chromatin immunoprecipitation (ChIP) is a powerful technique to study interactions between transcription factors (TFs) and DNA in vivo. For genome-wide de novo discovery of TF-binding sites, the DNA that is obtained in ChIP experiments needs to be processed for sequence identification. The sequences can be identified by direct sequencing (ChIP-SEQ) or hybridization to microarrays (ChIP-CHIP). Given the small amounts of DNA that are usually obtained in ChIP experiments, successful and reproducible sample processing is challenging. Here we provide a detailed procedure for ChIP of plant TFs, as well as protocols for sample preparation for ChIP-SEQ and for ChIP-CHIP. Our ChIP procedure is optimized for high signal-to-noise ratio starting with tissue fixation, followed by nuclei isolation, immunoprecipitation, DNA amplification and purification. We also provide a guide for primary data analysis of ChIP-SEQ data. The complete protocol for ChIP-SEQ/ChIP-CHIP sample preparation starting from plant harvest takes ~7 d
Tissue methionine cycle activity and homocysteine metabolism in female rats: impact of dietary methionine and folate plus choline
Wilson, F.A. ; Borne, J.J.G.C. van den; Calder, A.G. ; O'Kennedy, N. ; Holtrop, G. ; Rees, W.D. ; Lobley, G.E. - \ 2009
American Journal of Physiology. Endocrinology and Metabolism 296 (2009)4. - ISSN 0193-1849 - p. E702 - E713.
amino-acids - plasma homocysteine - kinetics - methylation - insulin - disease - humans - deficiency - liver - methyltransferase
Impaired transfer of methyl groups via the methionine cycle leads to plasma hyperhomocysteinemia. The tissue sources of plasma homocysteine in vivo have not been quantified nor whether hyperhomocysteinemia is due to increased entry or decreased removal. These issues were addressed in female rats offered diets with either adequate or excess methionine (additional methyl groups) with or without folate and choline (impaired methyl group transfer) for 5 wk. Whole body and tissue metabolism was measured based on isotopomer analysis following infusion with either [1-13C,methyl-2H3]methionine or [U-13C]methionine plus [1-13C]homocysteine. Although the fraction of intracellular methionine derived from methylation of homocysteine was highest in liver (0.18–0.21), most was retained. In contrast, the pancreas exported to plasma more of methionine synthesized de novo. The pancreas also exported homocysteine to plasma, and this matched the contribution from liver. Synthesis of methionine from homocysteine was reduced in most tissues with excess methionine supply and was also lowered in liver (P <0.01) with diets devoid of folate and choline. Plasma homocysteine concentration (P <0.001) and flux (P = 0.001) increased with folate plus choline deficiency, although the latter still represented
Comparative expression analysis of isolated human adipocytes and the human adipose cell lines LiSa-2 and PAZ6
Beek, E.A. van; Bakker, A.H. ; Kruyt, P.M. ; Vink, C. ; Saris, W.H. ; Keijer, J. - \ 2008
International Journal of Obesity 32 (2008)6. - ISSN 0307-0565 - p. 912 - 921.
differential gene-expression - brown adipocytes - tissue - white - fat - methylation - alpha - mouse - thiazolidinediones - preadipocytes
Objective: To obtain insight in the extent to which the human cell lines LiSa-2 and PAZ6 resemble isolated primary human adipocytes. Design: A combination of cDNA subtraction (representative difference analysis; RDA) and cDNA microarray analysis was used to select adipose specific genes to compare isolated (pre-)adipocytes with (un)differentiated LiSa-2 and PAZ6 cells. Measurements: RDA was performed on adipose tissue against lung tissue. A total of 1400 isolated genes were sequenced and cDNA microarray technology was used for further adipose related gene selection. 30 genes that were found to be enriched in adipose tissue were used to compare isolated human adipocytes and LiSa-2 and PAZ6 cells in the differentiated and undifferentiated states. Results: RDA and microarray analysis resulted in the identification of adipose enriched genes, but not in adipose specific genes. Of the 30 most differentially expressed genes, as expected, most were related to lipid metabolism. The second category consisted of methyltransferases, DNMT1, DNMT3a, RNMT and SHMT2, of which the expression was differentiation dependent and higher in differentiated adipocytes. Using the 30 adipose expressed genes, it was found that isolated adipocytes on one hand, and PAZ6 and LiSa-2 adipocytes on the other, differ primarily in lipid metabolism. Furthermore, LiSa-2 cells seem to be more similar to isolated adipocytes than PAZ6 cells. Conclusion: The LiSa-2 cell line is a good model for differentiated adipocytes, although one should keep in mind that the lipid metabolism in these cells deviates from the in vivo situation Furthermore, our results imply that methylation may have an important function in terminal adipocyte differentiation.
Eight-fold increased risk for congenital heart defects in children carrying the nicotinamide N-methyltransferase polymorphism and exposed to medicines and low nicotinamide
Driel, L.M.J.W. van; Smedts, H.P.M. ; Helbing, W.A. ; Isaacs, A. ; Lindemans, J. ; Uitterlinden, A.G. ; Duijn, C.M. van; Vries, J.H.M. de; Steegers, E.A.P. ; Steegers-Theunissen, R.P.M. - \ 2008
European Heart Journal 29 (2008)11. - ISSN 0195-668X - p. 1424 - 1431.
plasma homocysteine - gene - pregnancy - malformations - multivitamin - association - methylation - supplements - folate - bias
Aims: Congenital heart defects (CHDs) have a multifactorial origin, in which subtle genetic factors and peri-conception exposures interact. We hypothesize that derangements in the homocysteine and detoxification pathways, due to a polymorphism in the nicotinamide N-methyltransferase (NNMT) gene, low maternal dietary nicotinamide intake, and medicine use in the peri-conception period, affect CHD risk. Methods and results: In 292 case and 316 control families, maternal peri-conception medicine use and low dietary intake of nicotinamide (13.8 mg/day) were independently associated with CHD risk [odds ratio (95% confidence interval) 1.6 (1.1¿2.3) and 1.5 (1.03¿2.3), respectively]. No significant association was found for the NNMT AG/AA genotype in mothers [0.9 (0.7¿1.3)], fathers [1.1 (0.8¿1.6)], or children [1.1 (0.8¿1.6)]. However, the combination of peri-conception medicine use, low dietary nicotinamide intake, and the NNMT AG/AA genotype in mothers or children showed risk of 2.7 (1.02¿8.1) and 8.8 (2.4¿32.5), respectively. Conclusion: Children carrying the NNMT A allele face additional CHD risk in combination with peri-conception exposure to medicines and/or a low dietary nicotinamide intake. These findings provide a first set of data against which future studies with larger sample sizes can be compared with.
Fruits, vegetables and hMLH1 protein-deficient and-proficient colon cancer: the Netherlands Cohort Study
Wark, P.A. ; Weijenberg, M.P. ; Veer, P. van 't; Wijhe, G. van; Luchtenborg, M. ; Muijen, G.N.P. van; Goeij, A.F.P.M. de; Goldbohm, R.A. ; Brandt, P.A. van den - \ 2005
Cancer Epidemiology Biomarkers and Prevention 14 (2005)7. - ISSN 1055-9965 - p. 1619 - 1625.
sporadic colorectal-cancer - food frequency questionnaire - defective mismatch repair - scale prospective cohort - microsatellite instability - promoter region - proximal colon - methylation - diet - hypermethylation
Clinical and pathologic differences exist between colon carcinomas deficient and proficient in the mismatch repair protein hMLH1. Animal and in vitro studies suggest that fruits, vegetables, folate, and antioxidants are associated with colonic expression of mismatch repair genes.METHODS: Associations between consumption of fruits and vegetables and hMLH1 protein-deficient and -proficient colon cancer were evaluated in the Netherlands Cohort Study on diet and cancer using a case-cohort approach. A self-administered food frequency questionnaire was completed, in 1986, by 120,852 individuals ages 55 to 69 years. Using immunohistochemistry, hMLH1 protein expression was assessed in colon cancer tissue obtained from 441 patients who were identified over 7.3 years of follow-up excluding the initial 2.3 years. Incidence rate ratios (RR) were estimated for hMLH1 protein-deficient and -proficient colon cancer.RESULTS: hMLH1 protein expression was absent in 54 tumors (12.2%) and present in 387 tumors. Fruit consumption was associated with hMLH1 protein-deficient colon cancer [highest versus lowest tertile, RR, 0.46; 95% confidence interval (95% CI), 0.23-0.90; P(trend) = 0.029] but not with hMLH1 protein-proficient tumors (highest versus lowest tertile, RR, 1.03; 95% CI, 0.78-1.35; P(trend) = 0.81). Total consumption of vegetables was not associated with either type of tumor (hMLH1 protein deficient: RR, 0.86; 95% CI, 0.45-1.65; P(trend) = 0.67; hMLH1 protein proficient: RR, 0.94; 95% CI, 0.72-1.23; P(trend) = 0.72). No associations were observed for folate, fiber, antioxidants, or subgroups of vegetables.CONCLUSION: These analyses indicate that an inverse association between consumption of fruits and colon cancer may be confined to the subgroup of tumors with a deficient mismatch repair system.
Possible mechanisms behind the differential effects of soy protein and casein feedings on colon cancer biomarkers in the rat
Vis, E.H. ; Geerse, G.J. ; Klaassens, E.S. ; Boekel, M.A.J.S. van; Alink, G.M. - \ 2005
Nutrition and Cancer 51 (2005)1. - ISSN 0163-5581 - p. 37 - 44.
dietary soybean protein - bile-acids - cell-proliferation - saponin content - carcinogenesis - methionine - calcium - 1,2-dimethylhydrazine - methylation - consumption
In the present studies, several hypotheses were tested to explain previously reported differential effects of soy and casein on colon cancer biomarkers like cell proliferation, fecal fat, fecal bile acid, alkaline phosphatase, and magnesium excretion in rats. In Study 1, the effect of methionine, a limiting amino acid in soy protein and an amino acid that is thought to have a marked effect on colonic cell proliferation, was tested. It was concluded that methionine up to 1% in the diet had no effect on cell proliferation, using the 3H-thymidine assay. The same study revealed that fecal alkaline phosphatase excretion is a good marker for colonic epithelial damage and fecal magnesium excretion is not. In Study 2, the hypothesis was tested that soy fractions enriched with isoflavones and saponins may increase fat excretion and so influence colonic cell proliferation in rats. It was indeed shown that soy protein isolate and an ethanolic extract from soy protein isolate slightly increased fecal fat excretion (up to 1.7-fold). However, fecal water bile acid and free fatty acid concentrations were decreased after feeding soy protein-based diets compared with casein, and no difference in fecal alkaline phosphatase excretion was observed. In Study 3, the lytic potential of soy saponins and the interaction between saponins and some lytic bile acids were tested in vitro. Data suggest a protective effect from soy saponins by reducing lytic activity of cholic acid. The overall conclusion is that soy protein compared with casein influences several colon cancer risk parameters, indicating a more protective rather than a stimulating effect on colon cancer risk.
Validation of the high-throughput marker technology DArT using the model plant Arabidopsis thaliana
Wittenberg, A.H.J. ; Lee, T.A.J. van der; Cayla, C. ; Kilian, A. ; Visser, R.G.F. ; Schouten, H.J. - \ 2005
Molecular Genetics and Genomics 274 (2005)1. - ISSN 1617-4615 - p. 30 - 39.
single-nucleotide polymorphisms - large-scale identification - map-based cloning - primer extension - genome sequence - dna - methylation - arrays - information - inheritance
Diversity Arrays Technology (DArT) is a microarray-based DNA marker technique for genome-wide discovery and genotyping of genetic variation. DArT allows simultaneous scoring of hundreds of restriction site based polymorphisms between genotypes and does not require DNA sequence information or site-specific oligonucleotides. This paper demonstrates the potential of DArT for genetic mapping by validating the quality and molecular basis of the markers, using the model plant Arabidopsis thaliana. Restriction fragments from a genomic representation of the ecotype Landsberg erecta (Ler) were amplified by PCR, individualized by cloning and spotted onto glass slides. The arrays were then hybridized with labeled genomic representations of the ecotypes Columbia (Col) and Ler and of individuals from an F2 population obtained from a Col × Ler cross. The scoring of markers with specialized software was highly reproducible and 107 markers could unambiguously be ordered on a genetic linkage map. The marker order on the genetic linkage map coincided with the order on the DNA sequence map. Sequencing of the Ler markers and alignment with the available Col genome sequence confirmed that the polymorphism in DArT markers is largely a result of restriction site polymorphisms
Mode of action of Fusarium moniliforme endopolygalacturonase towards acetylated pectin.
Bonnin, E. ; Alebeek, G.J.W.M. van; Voragen, A.G.J. ; Thibault, J.F. - \ 2003
Carbohydrate Polymers 52 (2003). - ISSN 0144-8617 - p. 381 - 388.
aspergillus-niger - endo-polygalacturonase - methylation - acid - degradation - hydrolysis
Endopolygalacturonase from Fusarium moniliforme was used to degrade acetylated homogalacturonan previously prepared from sugar beet pulp. The initial velocity and the final percentage of hydrolysis decreased-very rapidly with increasing degree of acetylation, showing that acetyl substitution markedly affected the enzymatic activity. MALDI-TOF mass spectrometry was used to analyse the reaction products and to show acetyl groups on the oligogalacturonates. The results demonstrated that the enzyme was able to accommodate acetyl groups in its active site cleft. The influence of acetyl groups on the mode of action of the enzyme was discussed and compared to the influence of methyl groups. (C) 2003 Elsevier Science Ltd. All rights reserved.
Methylerings-methode volgens Christopherson & Glass
Rutjes, B.P.M. ; Muuse, B.G. - \ 1980
Wageningen : RIKILT (Verslag / RIKILT 80.48) - 3
vetzuren - methylering - gas-vloeistofchromatografie - dunnelaagchromatografie - fatty acids - methylation - gas liquid chromatography - thin layer chromatography
Vergelijkend onderzoek naar de methyleringsmethoden van vetzuren met KOH/MeOH en NaOMe volgens Christopherson en Glass. Middels DLC en GLC werden beide methyleringsmethoden van Christopherson & Glass getoetst op een aantal produkten. Daarbij werd onderzocht welke methode het meest geschikt is bij gebruik van het automatisch injectie-systeem GLC.
|On the methylation of inorganic mercury and the decomposition of organo-mercury compounds : a review
Lexmond, T.M. ; Haan, F.A.M. de; Frissel, M.J. - \ 1976
Wageningen : Institute for Land and Water Management Research (Technical bulletin / Institute for Land and Water Management Research no. 100) - 19
methylering - kwik - kwikverbindingen - anorganische verbindingen - organische kwikverbindingen - metabolisme - methylation - mercury - mercury compounds - inorganic compounds - organomercurial compounds - metabolism