High-resolution Gas-liquid Chromatography Research Articles

Analysis of Polybrominated Diphenyl Ethers and Lipid Composition in Human Breast Milk and Their Correlation with Infant Neurodevelopment.

Breastfeeding is recommended over formula feeding, but human breast milk (HBM) composition varies and can be affected by food additives. Whether flame-retardant polybrominated diphenyl ethers (PBDEs) found in HBM interact with lipid components of HBM to impede infant neurodevelopment is a critical public health issue. Using lipidomic analysis, we examined the association of PBDEs in HBM and HBM lipid components with infant neurodevelopment. HBM samples (n = 100) were collected at the beginning stage of breastfeeding and analyzed for 30 PBDE congeners as well as a group of lipid components by using high-resolution gas chromatography, mass spectrometry, and liquid chromatography time-of-flight mass spectrometry. Infants were examined at 8 to 12 months of age by using the Bayley-III to assess neurodevelopment. A total of seven PBDEs, 35 lipids, and 27 fatty acids in HBM showed significant associations with Bayley-III scores. Multivariate analysis confirmed that these candidate PBDEs and lipid components were significant predictors of infant neurodevelopment. Eicosapentaenoic acid and docosapentaenoic acid in HBM showed no association with infant neurodevelopment in the general Taiwanese population. While certain PBDEs may play a role, our findings indicate that the lipid components of HBM are directly important for infant neurodevelopment.

The Chemical Composition and Biological Activities of Essential Oil from the Leaves of Philadelphus x purpureomaculatus Lemoine

The essential oil from the leaves of Philadelphus x purpureomaculatus Lemoine was obtained by hydrodistillation and analyzed by high-resolution gas-liquid chromatography - mass spectrometry (GLC-MS). The essential oil of P. x purpureomaculatus leaves was dominated by terpenoids containing hydroxyl and carbonyl groups. The major components of P. x purpureomaculatus essential oil were viridiflorol (44.4%), manool (31.2%), pentadecanal (5.4%), and borneol (4.9%). Antioxidant capacity and cytotoxicity of methanol extracts and essential oil of P. x purpureomaculatus were evaluated by using DPPH-, ABTS-, FRAP- and MTTassays. Extracts from P. x purpureomaculatus have shown weak antioxidant activity compare with positive control (caffeic acid). The highest cytotoxicity effect was observed with methanol leave extract on CCRF-CEM cells with IC50 value 38.5 μg/ml.

Genderspecific differences of homocysteinemia and its influence on oxidative stress parameters and endothelial function in patients with stable forms of coronary heart disease

One of the early manifestations of atherosclerotic lesions is endothelial dysfunction developing under conditions of reduced nitric oxide production, hyperhomocysteinemia, and oxidative stress. Bearing in mind high interest shown to gender-specific peculiarities of cardiovascular diseases, it appears important to study the relationship between these features in men and women with stable forms of coronary heart disease (CHD). Material and methods. The study included 102 patients with sable COPD divided into 2 groups (men and women) and 40 practically healthy subjects. Plasma homocysteine levels were measured by high-resolution gas-liquid chromatography with fluorescent detector with the use of Eko-Novo Milikhrom A-02 apparatus (Russia). Standard methods were used to measure plasma lipids, products of their peroxidation (dienic conjugates and products reacting with 2-thibarbituric acid), antioxidant enzymes (glutathioneperoxidase, and superoxide dismutase in erythrocytes), activity of the ceruloplasmin-transferrin system (by electron paramagnetic resonance method), final metabolites of nitric oxide using the Gries reaction. The endothelial function was studies by ultrasound with the evaluation of endothelium-dependent vasodilation. Results. The mean levels of homocystein and final NO metabolites in men with stable CHD were 1.5 times higher (р=0,01) and 12% lower (р = 0,03) than in women. Endothelial dysfunction was more pronounced in men (р< 0,05). Conclusion. Patients with CHD exhibit significant gender-specific differences in blood levels of of homocystein and final NO metabolites as well as in endothelium-dependent vasoreactivity associated with intensification of lipid peroxidation and impairment of antioxidative protection.

Teneurs en acides gras polyinsaturés essentiels du lait maternel en France : évolution des teneurs en acides linoléique et alpha-linolénique

Background: Long-chain polyunsaturated fatty acids (LC-PUFA) are nutritionally important constituents of breast milk to support normal growth, immune function and central nervous system development of newborn infants. Both linoleic acid (18:2 n-6; LA) and alpha-linolenic acid (18:3 n-3; ALA), the essential fatty acids, precursors of n-6 and n-3 LC-PUFA, are also present in breast milk. Although the total amount of fat in human milk is fairly constant, the fatty acid composition can vary substantially depending on the diet of the mother. Large variations in the LA, ALA and DHA (22:6 n-3) contents are observed among countries. As reported by previous studies, the ALA consumption of the French population was 2-3 times lower than the recommended value. Since this period, the food industry offers more food products enriched in n-3 fatty acids. Objective: The present study aimed to investigate whether nutritional recommendations and the improvement of the n-3 PUFA content of foodstuffs have contributed to an improvement of the PUFA composition of human milk. For this purpose, the PUFA content of a large number of human milk samples collected in 2007 in different French regions were compared with previous data obtained in studies conducted in the nineties years (1993-1998).Study design and methods: Mature (postpartum day ≥ 30) human milk samples (n = 145) were provided in 2007 by eight French regional human milk banks (Bordeaux: n = 20; Dijon: n = 21; Ile-de-France: n = 18; Lyon: n = 20 ; Montpellier: n = 18 ; Nantes: n = 21 ; St Etienne: n = 6 ; Tours: n = 21), from healthy women volunteers with no particular health history. The fatty acid composition of breast milk was analyzed by high-resolution gas-liquid chromatography. Statistical analysis was performed with Kruskall Wallis and Mann and Whitney U tests (p Fatty acid composition of human milk samples did not differ significantly among the eight French regions. The proportions of saturated fatty acids were similar (means ranging from 44.9% to 48.7% of total fatty acids). Monounsaturated fatty acids also varied little, from 36.9% to 39.7%. Total n-6 and n-3 PUFA accounted for 12.5%-15.2%, with the n-6/n-3 PUFA ratio value close to 10, similar among the collect centers. Considering the overall results, LA ranged from 10.4% to 12.7%, and ALA from 0.72% to 0.95%. Comparison of previous data (1993-1998) to the present results showed opposite changes in both LA and ALA contents. Between the two periods, the LA level decreased by 17%, whereas the ALA level increased by 45%, and consequently the LA/ALA ratio value favorably decreased from 24 to 15. The LC-PUFA content remained unchanged.Conclusion: Basing on the PUFA composition of human milk, this large French study has showed favourable changes in consumption of both omega-6 and omega-3 fatty acid precursors.

Teneurs en acides gras polyinsaturés essentiels du lait maternel en France : évolution du contenu en acides linoléique et alphalinolénique au cours des 10 dernières années

Background: Long-chain polyunsaturated fatty acids (LC-PUFA) are nutritionally important constituents of breast milk to support normal growth, immune function and central nervous system development of newborn infants. Both linoleic acid (18:2 n-6; LA) and alpha-linolenic acid (18:3 n-3; ALA), the essential fatty acids, precursors of n-6 and n-3 LC-PUFA, are also present in breast milk. Although the total amount of fat in human milk is fairly constant, the fatty acid composition can vary substantially depending on the diet of the mother. Large variations in the LA, ALA and DHA (22:6 n-3) contents are observed among countries. As reported by previous studies (1993-2001), the ALA consumption of the French population was 2-3 times lower than the recommended value. Since this period, the food industry offers more food products enriched in n-3 fatty acids. Objective: The present study aimed to investigate whether current recommendations and improved n-3 PUFA content of food products comply with the actual breast-milk PUFA composition. For this purpose, the PUFA content of a large number of human milk samples collected in 2007 in different French regions were compared with previous data obtained in studies conducted in the nineties years (1993-1998). Moreover, this study aimed to confirm expected reduction of the trans fatty acid (TFA) intake resulting from decreased level of TFA in margarine and other dietary fats during the same period. Study design and methods: Mature (postpartum day ≥ 30) human milk samples (n = 145) were provided in 2007 by eight French regional human milk banks (Bordeaux : n = 20; Dijon: n = 21; Ile-de-France: n = 18; Lyon: n = 20; Montpellier: n = 18; Nantes: n = 21; St Etienne: n = 6; Tours: n = 21), from healthy women volunteers with no particular health history. The fatty acid composition of breast milk was analysed by high-resolution gas-liquid chromatography. Statistical analysis was performed with Kruskall Wallis and Mann and Whitney U tests (p < 0.05). Results: Fatty acid composition of human milk samples did not differ significantly among the eight French regions. The proportions of saturated fatty acids were relatively similar (means ranging from 44.9% to 48.7% of total fatty acids). Monounsaturated fatty acids also varied little, from 36.9% to 39.7%. Total n-6 and n-3 PUFA accounted for 12.5%-15.2%, with an n-6/n-3 PUFA ratio close to 10, similar among the collect centers. Considering the overall results, LA represented between 10.4% and 12.7%, and ALA varied from 0.72% to 0.95%. Comparison of our results to previous data (1993-1998) showed opposite changes for LA and ALA. During the last decade, the LA level has decreased by 17%, whereas the ALA level has increased by 45%, and hence in 2007, the LA/ ALA ratio was close to 14 versus 24 in 1993-1998. The LC-PUFA content remained unchanged. Concerning total TFA, their content was lower (– 37%; p < 0.0001) in 2007 than in 1997, respectively 1.3% and 2.1% of total fatty acids of breast milk. Conclusion: Basing on the PUFA composition of human milk, this large French study shows favourable changes in consumption of both omega-6 and omega-3 fatty acid precursors, and in TFA, in the course of last decade.

Analytical Methods for Quantification of Modified Fatty Acids and Sterols Formed as a Result of Processing

Fats and oils are often submitted to technological treatments before being consumed. Some treatments like refining, hydrogenation, and frying often lead to the formation of modified fatty acids such as cyclic fatty acid monomers (CFAM), geometrical fatty acid isomers, and/or oxidized fatty acids and sterols (cholesterol and phytosterols). Both cholesterol oxidation products (COP) and phytosterol oxidation products (POP), may be present in foods. As some of the newly formed components may present some adverse effects upon consumption, methods have been developed to analyze these compounds in food products and biological samples. Gas liquid chromatography (GC) on long polar columns (100m) is a good choice to quantify trans mono- and poly-unsaturated fatty acids. In some cases a pre-fractionation step using silver nitrate thin layer chromatography (AgNO3-TLC) may be necessary to avoid GC overlapping of cis and trans isomers. Analysis of CFAM usually involves transformation of the sample in fatty acid methyl esters (FAME) which after addition of an internal standard (IS) are further hydrogenated. An enrichment step using reverse phase high performance liquid chromatography (RP-HPLC) permits to obtain a fraction which consists of a mixture of CFAM and the IS. This fraction is further analyzed by GC on a polar column. The analysis of oxidized triacylglycerol monomers (oxTG) as a group was feasible by a combination of adsorption and size-exclusion chromatography. Quantification in used frying fats and oils around the limit of rejection for human consumption (25% polar compounds) has shown that the amount of oxTG range 5.9–9.4% expressed on fat or oil weight. In foods and biological tissues, the level of oxidized sterols (SOP) is often a very small fraction of their unoxidized forms. Analysis of SOP involved extraction of lipids, saponification or transesterification, enrichment, and subsequent qualitative and quantitative determination by GC and GC-MS, or HPLC and HPLC-MS. In addition, enrichment of SOP requires complete separation from the unoxidized sterols in order to separate these compounds even by high resolution GC capillary columns.

Heteroallyl-containing 5-nitrofuranes as new anti- Trypanosoma cruzi agents with a dual mechanism of action

New heteroallyl-containing 5-nitrofuranes were synthesized as potential anti- Trypanosoma cruzi agents with a dual mechanism of action, oxidative stress and inhibition of membrane sterol biosynthesis. Some of the derivatives were found to have high and selective activity against the proliferative stages of the parasite, with IC 50 values against the clinically relevant intracellular amastigote forms in the low micromolar to sub-micromolar range. Oxidative stress was verified measuring cyanide dependent respiration. Inhibition of the de novo sterol biosynthesis at the level of squalene epoxidase was confirmed, using high-resolution gas–liquid chromatography coupled to mass spectrometry, by the disappearance of the parasite’s mature sterols and the concomitant accumulation of squalene. The in vitro activities of these novel compounds were superior to that of nifurtimox, a nitrofuran currently used in the treatment of human Chagas’ disease, and terbinafine, a commercially available allylamine-based squalene epoxidase inhibitor. The results support further in vivo studies of some of these nitrofuran derivatives.

Dietary supplementation of obese children with 1000 mg alpha-linolenic acid per day: a placebo-controlled double blind study

Enhanced dietary intake of omega-3 fatty acids may benefit persons with increased cardiovascular risk, among them obese subjects. Incorporation of omega-3 fatty acids into the plasma lipids is a prerequisite to achieve the favorable effects; however, only very few data are available on the dose of omega-3 fatty acid supplementation in children. The aim of our study was to examine the effects of the consumption of a diet supplemented with 1000 mg alpha-linolenic acid daily on plasma lipids in obese children. In this two times six-week-long, placebo-controlled, crossover study, 9 obese children (age: 13.1 [2.5] years, body mass index: 31.2 [6.2] kg/m 2 ), median [IQR]) incorporated into their diet one egg and one meatball (50 g) per day from hens fed diets containing flaxseed oil, i.e. supplementary dietary intake of 1000 mg alpha-linolenic acid per day was provided. The fatty acid composition of plasma lipids was determined by high-resolution gas-liquid chromatography. Tendencies of increase were observed in the alpha-linolenic acid content of plasma lipids in the phospholipid, triacyl-glycerine and sterol-ester fractions after the supplementation with alpha-linolenic acid. In the non-esterified fatty acid fraction, the values of alpha-linolenic acid were significantly higher after the supplementation (0.11 [0.08] versus 0.14 [0.20], % weight/weight, p < 0.05), indicating the beginning of the accumulation of alpha-linolenic acid in plasma lipids. In obese children a six-week-long supplementation of the diet with 1000 mg alpha-linolenic acid per day increased significantly the contribution of omega-3 fatty acids only to the non-esterified fatty acids of plasma lipids, but had no significant effect on the esterified fractions. Increase of the dose of supplementation may be needed to influence omega-3 fatty acid status in obese children.

Analysis of α-Linolenic Acid Biohydrogenation Intermediates in Milk Fat with Emphasis on Conjugated Linolenic Acids

Ruminal biohydrogenation of α-linolenic acid is not fully understood compared with that of linoleic acid. Some hypothetical intermediates, that is, conjugated isomers of α-linolenic acid (cis-9,trans-11,cis-15 and cis-9,trans-13,cis-15 18:3) have never been reported to occur in ruminant fat. Therefore, milk fat was analyzed using a combination of techniques to characterize α-linolenic acid biohydrogenation intermediates. Tandem off-line argentation thin-layer chromatography and high-resolution gas-liquid chromatography using a 120-m highly polar, open tubular capillary column coated with 70% cyanoalkyl polysiloxane equivalent material was used for quantification. Structural characterization of fatty acids was achieved by gas-chromatography mass-spectrometry after synthesis of specific azo-derivatives. This study confirmed that minute amounts of α-linolenic acid biohydrogenation intermediates are present in milk fat. Routes involved in biohydrogenation of linoleic and α-linolenic acids in the rumen and subsequent endogenous metabolism of related biohydrogenation products are discussed.

Gas-Liquid Chromatography를 이용한 사과 및 배 중의 농약 다성분 잔류분석법

A rapid analytical method was developed to determine multiple pesticide residues in apples and pears using gas-liquid chromatography (GLC). The samples were extracted with water-miscible solvents and purified by cleanup procedures serially comprising liquid-liquid partition and solid-phase extraction (SPE). Each analyte was separated and determined by a high-resolution GLC equipped with electron-capture detector (ECD) and nitrogen-phosphorous detector (NPD). A total of 196 pesticides, which were previously classified into 5 groups each for ECD and NPD based on their retention behaviors on the capillary column and responses to the detector, were subjected to the recovery experiment. In compliance with the analytical criteria, 70 to 120% of recovery and less than 20% relative standard deviation the proposed method could be successfully applied to analyze 136 and 133 pesticide residues in apples and pears, respectively, which enabled not only rapid screening but quantitation of the residues. Even though less reliability was resulted from unacceptable recovery range, rest of pesticides including 43 and 45 analyzes in apples and pears, could be also detected for their identity. The proposed method fliled to cover 17 and 18 pesticides for apples and pears, which mostly showed high polarity or heat-lability but could be suitable far fast surveilance or monitoring of fruit harvests.

Abnormal fatty acid composition in umbilical cord blood of infants at high risk of atopic disease

It is well known that patients with atopic disease have anomalies of fatty acid composition in their blood. The aim of the present study was to evaluate whether infants from atopic families also have abnormal cord blood levels of long-chain polyunsaturated fatty acids (LC-PUFA) in plasma and red blood cells. The levels of LC-PUFA in umbilical cord blood of 50 healthy, full-term infants with a hereditary risk of atopic disease were analysed and compared with a control group of 50 infants from families without a history of atopic disease. The atopy group was comprised of children from families suffering from atopic dermatitis, allergic rhinitis, asthma bronchiale and food allergy. Within this group, a group (n = 11) was formed in which the risk was determined only by paternal atopy. Fatty acids of plasma and red blood cell phospholipids, triglycerides and sterol esters were separated by high-resolution gas-liquid chromatography. In particular, the levels of arachidonic acid (C20:4n-6) and docosatetraenoic acid (C22:4n-6) were significantly lower in infants at risk of atopic disease than in infants not at risk. Interestingly, there were more significant differences shown between the control group and the paternal atopy group than between the control group and the entire atopy group. The results of this study could be due to a genetic influence of fatty acid metabolism or could reflect the different dietary behaviours of the mothers during pregnancy.

Abnormal fatty acid composition in umbilical cord blood of infants at high risk of atopic disease

It is well known that patients with atopic disease have anomalies of fatty acid composition in their blood. The aim of the present study was to evaluate whether infants from atopic families also have abnormal cord blood levels of long-chain polyunsaturated fatty acids (LC-PUFA) in plasma and red blood cells. The levels of LC-PUFA in umbilical cord blood of 50 healthy, full-term infants with a hereditary risk of atopic disease were analysed and compared with a control group of 50 infants from families without a history of atopic disease. The atopy group was comprised of children from families suffering from atopic dermatitis, allergic rhinitis, asthma bronchiale and food allergy. Within this group, a group (n= 11) was formed in which the risk was determined only by paternal atopy. Fatty acids of plasma and red blood cell phospholipids, triglycerides and sterol esters were separated by high-resolution gas-liquid chromatography. In particular, the levels of arachidonic acid (C20:4n-6) and docosatetraenoic acid (C22:4n-6) were significantly lower in infants at risk of atopic disease than in infants not at risk. Interestingly, there were more significant differences shown between the control group and the paternal atopy group than between the control group and the entire atopy group. Conclusion: The results of this study could be due to a genetic influence of fatty acid metabolism or could reflect the different dietary behaviours of the mothers during pregnancy.

Lipids in human milk.

I have reviewed recent (March 1995-December 1997) papers on human milk lipids including many on fatty acid (FA) composition. The effects of maternal diets on the profiles are apparent. However, more data on the composition of milk lipids are needed. It is noteworthy that so few papers on milk FA composition have reported analyses using high-resolution gas-liquid chromatography columns. Two of these were on milk from women in North America. The diets in North America are varied and the number of analyses few. We do not have a reliable data base showing the ranges of biologically important acids. Except for the gangliosides, few new data on the other lipids appeared during this period.

PSYCHOMOTOR DEVELOPMENT OF TERM INFANTS RECEIVING LC-PUFA-ENRICHED FORMULA IN A PROSPECTIVE, RANDOMIZED, DOUBLE BLIND STUDY

Aims: Recent clinical studies have shown the importance of dietary LC-PUFA supplementation in preterm infants. Our current study evaluates whether n-3 and n-6 LC-PUFA are required in formula-fed term infants for psychomotor development in the first 18 months of life. We report the first results of 2, 4 and 9 months of age. Methods: A total of 85 healthy term infants were included in the study. They received human milk (HM) or were randomized to a conventional formula (FM-) or LC-PUFA enriched formula (FM+) (docosahexaenoic acid, DHA: 0.5%; arachidonic acid, AA: 0.11% of total lipids). For psychomotor development the Griffiths developmental test was used. Fatty acids of red blood cells (RBC) and plasma phospholipids (PL), plasma triglycerides and sterol esters were seperated by high-resolution gas-liquid chromatography. Results: Psychomotor development, body weight, heigth, head circumferences and skin fold measurements were not significantly different among the dietary groups at 2, 4 and 9 months. The levels (%(wt/wt), medians, interquartile ranges) of selected fatty acids found in umbilical cord blood (UCB) and at 2 and 4 mon of age are shown in the table. Conclusions: Supplementation of formula with 0.5% DHA and 0.11% AA of total lipids caused significantly higher levels of DHA in RBC-PL in term infants in comparison to breast-fed infants and conventional formula fed infants. In plasma lipids AA content was significantly lower. Psychomotor development was not affected by LC-PUFA supplementation.

Fatty acid composition of human milk during the 1st month after term and preterm delivery.

The fatty acid composition of human breast milk was determined longitudinally after term and preterm delivery by high resolution gas liquid chromatography. Milk samples were obtained at days 5, 10, 20 and 30 after term (n = 38) or preterm (n = 19) delivery. The saturated fatty acids C10:0 and C12:0 and the polyunsaturates linoleic acid (C18:2 omega-6) and alpha-linolenic acid (C18:3 omega-3) increased significantly from day 5 to day 10, whereas arachidonic acid (C20:4 omega-6), total omega-6 long-chain polyunsaturates (LCP), docosahexaenoic acid (C22:6 omega 3) and total omega-3 LCP decreased significantly. Term and preterm milk did not differ in percentage content of linoleic acid, alpha-linolenic acid and LCP at any time point. Preterm milk contained significantly more medium and intermediate chain fatty acids (C10:0, C12:0 and C14:0) than term milk on days 5 (12.28 vs 9.78%; P > 0.05), 10 (16.25 vs 12.62%; P > 0.05) and 20 (17.29 vs 13.47%; P > 0.005). The milk of mothers of preterm infants is not better suited to meet the high LCP requirements of their infants during the first weeks after birth. The slightly higher proportion of medium and intermediate chain fatty acids in preterm milk during the 1st month after birth might be advantageous for the fat and calcium absorption of preterm infants.

Gas chromatographic determination of muramic acid, glucosamine, mannosamine, and galactosamine in soils

Muramic acid, glucosamine, mannosamine and galactosamine in soils may be useful for elucidating the microbial origin of soil organic nitrogen. Therefore, a method was developed to determine the aldononitrile acetate derivatives of the four amino sugars simultaneously in the 6 m HCl hydrolysates of soil samples by means of high resolution gas liquid chromatography. This method was sensitive enough to detect less than 10 μg muramic acid ml −1 and less than 20 μg ml −1 of the other three amino sugars. The maximum release of amino sugars was found after 6 to 8 h hydrolysis at 105°C. Impurities in the acidic hydrolysates were removed simply by neutralisation with KOH solution. The recovery of amino sugars after hydrolysis and purification was more than 90% on average. The method was applied to determine amino sugars in eight soils with different properties. The coefficients of variation averaged 6.1% for glucosamine and galactosamine and 10.9% for muramic acid and mannosamine.

Analysis of several pesticides along the unsaturated zone in an experimental citrus grove of Castellon (Spain)

A study was carried out in an experimental citrus grove in order to determine the presence and movement of pesticides along the unsaturated zone before reaching the aquifer. Several pesticides widely used in the area (dicofol, tetradifon, dimethoate, fenitrothion, methidathion and MCPA) were spread on the grove at their recommended doses. Samples of soil solution were collected at several depths (0.2, 0.5, 1.5, 2.5 and 3.4 m) by using pressure-vacuum soil water samplers. Analysis of pesticides in water samples were carried out by high resolution gas-liquid chromatography using a dual detection system with ECD and NPD, capillary column (Ultra 2, Hewlett-Packard, 25 m, 0.20 mm i.d., 0.33 μm film thickness) and splitless injection system. High performance liquid chromatography with UV-Vis detection and reversed phase column was used for the determination of MCPA. Sampling and analysis were performed monthly, starting in December 1990. Samples of groundwater from several wells in an area within 5 km around the experimental grove were also analyzed for pesticides in order to complete data from this study. Preliminary results obtained in the analysis of soil solution water from unsaturated zone and groundwater samples are presented in this paper.

Gas-Liquid Chromatographic Analysis of Cellular Fatty Acid Methyl Esters in Aeromonas Species

The cellular fatty acids of 39 strains belonging to the genus Aeromonas (Aeromonas hydrophila, Aeromonas caviae, Aeromonas sobria, Aeromonas media, Aeromonas schubertii, Aeromonas veronii) were determined by high resolution gas-liquid chromatography. The fatty acid profiles were characterized by major amounts (60% or more) of one saturated (hexadecanoic acid = 16:0) and two unsaturated (hexadecenoic acid = 16:1 and octadecenoic acid = 18:1) acids. While the majority of the strains of the six species exhibited, qualitatively, very similar fatty acid compositions, only minor and inconsistent differences could be observed which would be useful for a distinction of the different taxons. The following fatty acids were qualitatively identified: 12:0, i-13:0, 14:0, 3-OH 13:0, i-15:0, 15:0, 2-OH 14:0, 3-OH 14:0, i-16:0, 16:1, 16:0, i-17:1, i-17:0, a-17:0, 17:0 cyclopropane, 17:1, 17:0, 18:1 (3 isomers), 18:0 and i-20:0. Excellent congruence was found in reproducibility studies. Fatty acid analyses show a great homogeneity within the group and the technique does not appear to be the ideal method in distinguishing between Aeromonas species.

&lt;i&gt;Cis&lt;/i&gt;- and &lt;i&gt;Trans&lt;/i&gt;-Isomeric Fatty Acids in Plasma Lipids of Newborn Infants and Their Mothers

The proportionate fatty acid composition of plasma lipids was determined by high-resolution gas-liquid chromatography in 30 pairs of mothers and their term infants at the time of birth. Trans-fatty acids were found at similar percentage levels in maternal and infantile plasma, evidence for the first time of their placental permeability. In umbilical plasma, linoleic and alpha-linolenic acids contributed markedly smaller portions to total fatty acids, in contrast to clearly higher proportions of their long-chain polyunsaturated metabolites (LCP). Significantly larger percentage values in cord than in maternal plasma were found for those LCP that are structural components of brain lipids, which may reflect a discriminating placental transport mechanism for certain physiologically important LCP.

Hydrocarbon weathering in seashore invertebrates and sediments over a two-year period following the Amoco cadiz oil spill: Influence of microbial metabolism

The weathering of aliphatic and aromatic hydrocarbons from the Amoco Cadiz oil was monitored from May 1978 to January 1980 in selected seashore invertebrates and sediments of the polluted area in Brittany, using high temperature high resolution gas-liquid chromatography. The major part of the oil was relatively rapidly eliminated but some petroleum constituents, such as long-chain n-alkanes, triterpanes and alkylated phenanthrenes and dibenzothiophenes, appeared to persist for a time. In high energy sites (Roscoff beach), depuration was generally quite complete between 12 and 18 months after the wreck, whereas, in sheltered muddy sediments and associated organisms of Aber Benoît and Aber Wrach, the presence of neosynthesised very long-chain alkanes up to nC56 was shown. These compounds are believed to result from bacterial metabolism and were still clearly visible 22 months after the accident. The similarity of hydrocarbon spectra in sediments and in associated organisms indicates that the level and the nature of the invertebrate contamination results from a dynamic equilibrium between a non-selective direct uptake of particulate polluted elements from the surrounding sediments, acting as a chronic pollution source, and a simultaneous depuration process including passive excretion of oil residuals and active metabolisation of some medium molecular weight compounds, like pristane and phytane. Microbial degradation was the main weathering factor and bacterial counts in the Aber Benoît muds showed that almost all the bacteria present were adapted to hydrocarbon utilisation.