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PubMed1992

Limitations of the triolein breath test.

Patients being investigated for intestinal absorptive capacity were classified as normals or malabsorbers on the basis of three fat absorption tests. Malabsorbers were further classified as mild, moderate, severe or gross according to severity of malabsorption. Using this classification system the triolein breath test was evaluated in 53 patients. Seventeen patients were excluded because their graph of percentage breath [14C]carbon dioxide versus time was exponential indicating that the peak [14C]-carbon dioxide may be occurring later than the six hour duration of the test. The sensitivity and specificity of the triolein breath test were found to be 100% and 96%, respectively and moderate correlations with the individual fat absorption tests were found. However, the breath test was limited in its capacity to predict the severity of malabsorption. Carbon dioxide output was also measured in order to determine the applicability of using an assumed value. The respiratory quotient and variability of results were high in nineteen patients indicating possible hyperventilation. In 32 patients with reproducible results and normal respiratory quotients the average carbon dioxide output was 8.66 mmol/kg per hour with a wide range of 5-12.4 mmol/kg per hour. Consequently the use of an assumed carbon dioxide output can introduce considerable errors in the triolein breath test. This study highlights drawbacks of the triolein breath test, particularly problems in using an assumed carbon dioxide output for its calculation, its inability to predict the severity of malabsorption and the nature of the dietary load used.

Adolescent↗
PubMed1984

Effect of surface composition on triolein hydrolysis in phospholipid vesicles and microemulsions by a purified acid lipase.

Sonicated dispersions of egg yolk phosphatidylcholine and triolein as vesicles and microemulsions have been used as substrates for the assay of a purified acid lipase. Previous studies have also shown that triolein localized in the surface phase of emulsions is the preferred substrate. In this study, we examined enzyme activity following several surface modifications using both vesicles and microemulsions. When the acidic phospholipids phosphatidylserine and phosphatidic acid were incorporated into both vesicles and microemulsions at up to 10 mol % of the total phospholipid, a dose-dependent reduction in the apparent Km was observed. Using the vesicles as substrate, a dose-dependent decrease in Vmax was also observed. Agarose gel electrophoresis was used to verify suspected changes in net particle charge. Analogous inclusion of phosphatidylethanolamine, sphingomyelin, or cholesterol did not affect kinetic parameters. Addition of oleic acid to sonication mixtures produced vesicles with a decreased apparent Km and Vmax, but triolein hydrolysis in microemulsions was not significantly altered. Triolein-containing vesicles prepared by using dimyristoyl- or dipalmitoylphosphatidylcholine were hydrolyzed maximally at the gel liquid-crystalline transition temperatures of the appropriate phospholipid. Differential scanning calorimetry was used to verify the temperatures of transition in these vesicles. The results indicate that acid lipase activity is influenced by the charge or physical state of the surface phase of model substrates and suggest that degradation of core components of naturally occurring substrates such as lipoprotein may be influenced by chemical changes on the surface of these particles.

Animals↗
PubMedDate not supplied

Structure and properties of triolein-based polyurethane networks.

Polyurethane networks based on vegetable oils have very heterogeneous composition, and it is difficult to find a close correlation between their structure and properties. To establish benchmark structure-properties relationships, we have prepared model polyurethane networks based on triolein and 4,4'-diphenylmethane diisocyanate (MDI). Cross-linking in the middle of fatty acid chains leaves significant parts of the triglyceride as dangling chains. To examine their effect on properties, we have synthesized another polyurethane network using triolein without dangling chains (removed by metathesis). The structure of polyols was studied in detail since it affects the structure of polyurethane networks. The network structure was analyzed from swelling and mechanical measurements and by applying network and rubber elasticity theories. The cross-linking density in both networks was found to be close to theoretical. The triolein-based model network displayed modulus (around 6 MPa), tensile strength (8.7 MPa), and elongation at break (136%), characteristic of hard rubbers. Glass transition temperatures of the networks from triolein and its metathesis analogue were 25 and 31.5 degrees C, respectively.

Molecular Structure↗
PubMed2001

Effect of oleic and linoleic acids on the production of deep-fried odor in heated triolein and trilinolein.

To determine sources of desirable deep-fried flavor in frying oils, degradation products from heated triolein and trilinolein with 5-31% polar compounds representing low to high deterioration were evaluated by purge-trap gas chromatography-mass spectrometry-olfactometry. (E,E)-2,4-Decadienal, 2-heptenal, 2-octenal, 2,4-nonadienal, and 2,4-octadienal produced deep-fried odor at moderate-strong intensities in heated trilinolein. However, unexpected aldehydes-2,4-decadienal, 2,4-undecadienal, 2,4-nonadienal, and 2-octenal (all <15 ppm)-were produced in triolein heated for 6 h. These dienals possibly were produced by hydroperoxidation and/or hydroxylation followed by dehydration of 2-alkenals. The 2-alkenals were produced from thermal decomposition of hydroperoxides, epoxides, and keto and dimeric compounds produced during the heating of triolein. These aldehydes produced low intensities of deep-fried odor in triolein. This information helps to explain sources of the deep-fried flavor that is characteristic of high linoleic frying oils but which is only at low intensity levels in high oleic frying oils.

Chromatography, High Pressure Liquid↗
PubMed2003

Dynamics of competitive adsorption of alphas-casein and beta-casein at planar triolein-water interface: evidence for incompatibility of mixing in the interfacial film.

Competitive adsorption of alpha(s)-casein and beta-casein from a bulk solution mixture to the triolein-water interface has been studied. Although the binding affinity of alpha(s)-casein to the triolein-water interface was lower than that of beta-casein in single-component systems, in a 1:1 mixture of alpha(s)-casein and beta-casein in the bulk solution the ratio of interfacial concentrations of alpha(s)-casein to beta-casein at equilibrium was about 2:1, indicating that alpha(s)-casein was preferentially adsorbed to the triolein-water interface. Furthermore, the equilibrium composition of alpha(s)-casein and beta-casein in the interfacial film at various bulk concentration ratios did not follow a simple Langmuir adsorption model. This deviation from ideal behavior was mainly due to thermodynamic incompatibility of mixing of these caseins in the interfacial region. The value of the incompatibility parameter, X(12), for these caseins at the triolein-water interface was much greater than that at the air-water interface. Displacement experiments showed that while alpha(s)-casein could dynamically displace beta-casein when the latter was in an unsaturated monolayer state at the interface, it could not do so when beta-casein was in a saturated monolayer film state. It is hypothesized that, because of thermodynamic incompatibility of mixing, the alpha(s)-casein and beta-casein mixed film at the oil-water interface may undergo two-dimensional phase separation.

Adsorption↗
PubMed2005

Differences in labelled triolein turnover after oral administration between liver and adipose tissue of rats.

To investigate exogenous triacylglycerol turnover, the time courses for labelled triolein in the liver, plasma and epididymal adipose tissue (adipose tissue) after oral administration to rats fed a fat-free or 10 % corn oil diet for 3 d after fasting overnight were examined for 10 d. After the administration of labelled triolein to rats fed the fat-free diet, the incorporation (dpm/g) into total lipids of the liver and adipose tissue each reached the maximum in 8 h and was seven times higher in the adipose tissue than in the liver. The half-lives of total lipid radioactivities during the decreasing phases were 0.39 and 2.58 d, respectively, in the rapid and slow phases of the decay curve in the liver, and 4.78 d in only one phase of the adipose tissue. Radioactivity after administration of labelled triolein was mostly found in the oleic acid in the tissues. The half-life of oleic acid was 3.92 d in the adipose tissues. These half-lives were similar in both dietary groups. Thus, although dietary corn oil reduced the triolein incorporation to cellular lipids in comparison to the fat-free diet, it did not affect these half-lives. The labelled triacylglycerol-oleic acid stayed abundantly intact for a long time in the adipose tissue and was scarcely changed to other fatty acids, whereas it was slightly incorporated into total lipids and quickly metabolized in the liver. Non-essential fatty acids may be mostly endogenous in the liver but may be exogenous and endogenous in adipose tissue.

Adipose Tissue↗
PubMed1979

Effects of tristearin, triolein and safflower oil diets on cholesterol balance in rats.

Diets containing relatively homogeneous triglycerides composed of 18-carbon chain saturated, monounsaturated or polyunsaturated fatty acids were fed to rats. Cholesterol absorption and turnover were studied. Cholesterol absorption was significantly less in rats fed tristearin than in animals fed triolein or safflower oil. Cholesterol removal from plasma was fastest in rats fed tristearin and slowest with safflower oil and triolein. Plasma cholesterol levels were lowest with tristearin and highest with safflower oil. Increased cholesterol in high density lipoproteins was observed with tristearin and triolein. Lymph and hepatic cholesterol, and lymph triglycerides were highest with safflower oil, suggesting endogenous mobilization. Cholesterol production was least with triolein. Sterol synthesis was greatest with tristearin, perhaps attributable to decreased negative feedback analogous to effects of cholestyramine. Differences in lipoprotein composition observed with the various diets are important since effects on particle size and shape may influence removal mechanisms. The mechanisms underlying the different effects of dietary triglycerides on sterol absorption and metabolism remain to be elucidated.

Animals↗
PubMed1984

Clinical evaluation of the 14C-Triolein Breath Test: a critical analysis.

Twenty-two hospital patients without gastrointestinal symptoms and fourteen patients with clinically suspected fat malabsorption were studied using the 14C-Triolein Breath Test and three day fecal fat estimation. The 14C-Triolein Breath Test was 100% sensitive and 86% specific for fat malabsorption. Three day fecal fat estimations were 86% sensitive and 91% specific. These data confirm the high sensitivity and specificity obtained using the 14C-Triolein Breath Test. The speed and convenience of the 14C-Triolein Breath Test plus acceptable sensitivity and specificity make this a practical screening test to detect fat malabsorption.

Adult↗
PubMed1971

Use of unabsorbed radioactive marker substances in a re-assessment of the radioactive triolein test of fat absorption.

The radioactive triolein test has been compared with two chemical methods for the assessment of fat absorption in a group of inpatients from general medical wards. The special feature of the investigation is the use of a radioactive faecal marker to measure the completeness of faecal collections during the investigation period. Estimations of unabsorbed (131)I triolein and faecal fat measured by the chemical methods were made on the same specimens. The results showed that only 48% of the patients provided a complete collection of faeces (defined as a recovery of more than 90% of the faecal marker). From these patients good correlations were found between the triolein absorption test and the two chemical methods.It is suggested that previous criticism of the radioactive triolein test may have been due to incomplete faecal collections causing false results.

Chemistry Techniques, Analytical↗
PubMed2005

Acidolysis between triolein and short-chain fatty acid by lipase in organic solvents.

Ten kinds of lipases were examined as biocatalysts for the incorporation of short-chain fatty acids (acetic, propionic, and butyric acids) into triolein in order to produce one kind of reduced-calorie structured lipids. Trans-esterification (acidolysis) was successfully done in n-hexane by several microbial lipases. Among them, lipase from Aspergillus oryzae was used to investigate the effects of incubation time, substrate molar ratio, and water content on acidolysis. Finally, more than 80% of triolein was incorporated by butyric acid (molar ratio of triolein to butyric acid, 1:10) in the dried n-hexane at 52 degrees C for 72 h. More than 90% of the products was monosubstituent, which was esterified with this short chain fatty acid at the 1-position of the glycerol moiety of triolein. These results suggest that A. oryzae lipase would be a powerful biocatalyst for the synthesis of low caloric oil, such as triacylglycerol containing a mixture of long- and short-chain aliphatic acids.

Aspergillus oryzae↗
PubMed1983

14C-triolein breath test as a rapid and convenient screening test for fat malabsorption.

The 14C-triolein breath test was evaluated as a screening test for fat malabsorption in 50 consecutive patients. After the ingestion of a 30-g fat meal containing 5 microCi 14C-triolein, the breath excretion of 14CO2 was measured at hourly intervals for 6 h and compared with a 3-day faecal excretion of fat. Nineteen patients had steatorrhoea and 31 patients normal fat excretion. The maximum specific activity of CO2 in the breath provided the best means of distinguishing between the two groups, with no false-negative values and nine false-positive values (29%). Our findings confirm that the 14C-triolein breath test is sensitive and has sufficient specificity for screening fat malabsorption, especially among outpatients. If a normal 14C-triolein breath test is obtained, it seems unnecessary to perform measurements of excretion of faecal fat.

Adult↗
PubMed2002

Experimental cerebral fat embolism: embolic effects of triolein and oleic acid depicted by MR imaging and electron microscopy.

BACKGROUND AND PURPOSE: In fat embolism, free fatty acid is more toxic than neutral fat in terms of tissue damage. We evaluated the hyperacute embolic effects of triolein and oleic acid in cat brains by using MR imaging and electron microscopy. METHODS: T2-weighted imaging, diffusion-weighted imaging, and contrast-enhanced T1-weighted imaging were performed in cat brains after the injection of triolein (group 1, n = 8) or oleic acid (group 2, n = 10) into the internal carotid artery. MR images were quantitatively assessed by comparing the signal intensity ratios of the lesions with their counterparts on T2-weighted images, apparent diffusion coefficient (ADC) maps, and contrast-enhanced T1-weighted images. Electron microscopic findings in group 1 were compared with those in group 2. RESULTS: Qualitatively, MR images revealed two types of lesions. Type 1 lesions were hyperintense on diffusion-weighted images and hypointense on ADC maps. Type 2 lesions were isointense or mildly hyperintense on diffusion-weighted images and isointense on ADC maps. Quantitatively, the signal intensity ratios of type 1 lesions in group 2 specimens were significantly higher on T2-weighted images (P =.013)/(P =.027) and lower on ADC maps compared with those of group 1. Electron microscopy of type 1 lesions in both groups revealed more prominent widening of the perivascular space and swelling of the neural cells in group 2, in contrast to notable endothelial defects in group 1. CONCLUSION: MR and electron microscopic data on cerebral fat embolism induced by either triolein or oleic acid revealed characteristics suggestive of both vasogenic and cytotoxic edema in the hyperacute stage. Tissue damage appeared more severe in the oleic acid group than in the triolein group.

Animals↗
PubMed2006

The study of cerebral hemodynamics in the hyperacute stage of fat embolism induced by triolein emulsion.

PURPOSE: The purpose of this study was to evaluate the cerebral hemodynamic change in the hyperacute stage of cerebral fat embolism induced by triolein emulsion, by using MR perfusion imaging in cat brains. METHODS: By using the femoral arterial approach, the internal carotid arteries of 14 cats were infused with an emulsion of triolein 0.05 mL. T2-weighted (T2WI), diffusion-weighted (DWI), apparent diffusion coefficient (ADC) map, perfusion-weighted (PWI), and gadolinium-enhanced T1-weighted (Gd-T1WI) images were obtained serially at 30 minutes and 2, 4, and 6 hours after infusion. The MR images were evaluated qualitatively and quantitatively. Qualitative evaluation was performed by assessing the signal intensity of the serial MR images. Quantitative assessment was performed by comparing the signal-intensity ratio (SIR) of the lesions to the contralateral normal side calculated on T2WIs, Gd-T1WIs, DWIs, and ADC maps at each acquisition time and by comparing the relative cerebral blood volume (rCBV), cerebral blood flow (CBF), and mean transit times (MTT) of the lesions to the contralateral normal side calculated on PWI. RESULTS: In the qualitative evaluation of the MR images, the lesions showed hyperintensity on T2WIs, enhancement on the Gd-T1WIs, and isointensity on DWIs and the ADC maps. In the quantitative studies, SIRs on the Gd-T1WIs, DWIs, and ADC maps peaked at 2 hours after infusion. The SIRs on the T2WIs peaked at 4 hours after infusion and decreased thereafter. On PWIs, the rCBV, rCBF, and MTT of the lesion showed no significant difference from the contralateral normal side (P = .09, .30, and .13, respectively) and showed no significant change of time course (P = .17, .31, and .66, respectively). CONCLUSION: The embolized lesions induced by triolein emulsion showed no significant difference in cerebral hemodynamic parameters from those on the contralateral normal side. The result may suggest that consideration of the hemodynamic factor of embolized lesions is not necessary in further studies of the blood-brain barrier with triolein emulsion.

Acute Disease↗
PubMed1982

Diagnosis and differentiation of fat malabsorption in children using 13C-labeled lipids: trioctanoin, triolein, and palmitic acid breath tests.

Three substrates labeled with nonradioactive 13C have been employed to establish a trilogy of noninvasive breath tests to detect fat malabsorption in children and then to differentiate the etiology of the steatorrhea. Administration of 17 mg/kg of (13C)triolein Lipomul (The Upjohn Co., Kalamazoo, Mich.) resulted in a peak excretion rate of 13CO2 greater than 2.7% dose/h in 10 normal subjects (mean value 4.96 +/- 2.2% dose/h) whereas all 17 subjects with fat malabsorption were below this value (mean value, 0.75% +/- 0.63% dose/h); p less than 0.001). For the detection of fat malabsorption, the discriminative value of (13C)triolein was superior, 100% sensitive, and 89% specific, while the use of (13C)palmitic acid (17 mg/kg) or (13C)trioctanoin (7.5 mg/kg) alone yielded both false-positive and false-negative results. In 6 out of 6 cases, pancreatic insufficiency could be differentiated from mucosal disease (7 patients) or bile salt deficiency (4 patients) by the presence of abnormal triolein or trioctanoin breath tests, or both but normal palmitic acid breath tests. However, further differentiation of mucosal disorders from bile salt disorders could not be achieved using either a single- or a multiple-substrate breath test. The use of the single triolein breath test in children offers an attractive, sensitive alternative to conventional fecal fat measurements to establish the presence of steatorrhea, and when using 12C-lipid with multiple substrates, the tests are capable of providing additional insight into the mechanism of fat malabsorption.

Adolescent↗
PubMed2001

Final report on the safety assessment of trilaurin, triarachidin, tribehenin, tricaprin, tricaprylin, trierucin, triheptanoin, triheptylundecanoin, triisononanoin, triisopalmitin, triisostearin, trilinolein, trimyristin, trioctanoin, triolein, tripalmitin, tripalmitolein, triricinolein, tristearin, triundecanoin, glyceryl triacetyl hydroxystearate, glyceryl triacetyl ricinoleate, and glyceryl stearate diacetate.

Triesters of glycerin and aliphatic acids, known generically as glyceryl triesters and specifically as Trilaurin, etc., are used in cosmetic products as occlusive skin-conditioning agents and/or nonaqueous viscosity-increasing agents. Hundreds of glyceryl triesters are used in a wide variety of cosmetic products at concentrations ranging from a few tenths of a percent to 46%. Glyceryl triesters are also known as triglycerides; ingested triglycerides are metabolized to monoglycerides, free fatty acids, and glycerol, all of which are absorbed in the intestinal mucosa and undergo further metabolism. Dermal absorption of Triolein in mice was nil; the oil remained at the application site. Only slight absorption was seen in guinea pig skin. Tricaprylin and other glyceryl triesters have been shown to increase the skin penetration of drugs. Little or no acute, subchronic, or chronic oral toxicity was seen in animal studies unless levels approached a significant percentage of caloric intake. Subcutaneous injections of Tricaprylin in rats over a period of 5 weeks caused a granulomatous reaction characterized by oil deposits surrounded by macrophages. Dermal application was not associated with significant irritation in rabbit skin. Ocular exposures were, at most, mildly irritating to rabbit eyes. No evidence of sensitization or photosensitization was seen in a guinea pig maximization test. Most of the genotoxicity test systems were negative. Tricaprylin, Trioctanoin, and Triolein have historically been used as vehicles in carcinogenicity testing of other chemicals. In one study, subcutaneous injection of Tricaprylin in newborn mice produced more tumors in lymphoid tissue than were seen in untreated animals, whereas neither subcutaneous or intraperitoneal injection in 4- to 6-week-old female mice produced any tumors in another study. Trioctanoin injected subcutaneously in hamsters produced no tumors. Trioctanoin injected intraperitoneally in pregnant rats was associated with an increase in mammary tumors in the offspring compared to that seen in offspring of untreated animals, but similar studies in pregnant hamsters and rabbits showed no tumors in the offspring. One study of Triolein injected subcutaneously in rats showed no tumors at the injection site. As part of an effort to evaluate vehicles used in carcinogenicity studies, the National Toxicology Program conducted a 2-year carcinogenicity study in rats given Tricaprylin by gavage. This treatment was associated with a statistically significant dose-related increase in pancreatic acinar cell hyperplasia and adenoma, but there were no acinar carcinomas, the incidence of mononuclear leukemia was less, and nephropathy findings were reduced, all compared to corn oil controls. Overall, the study concluded that Tricaprylin did not offer significant advantages over corn oil as vehicles in carcinogenicity studies. Trilaurin was found to inhibit the formation of neoplasms initiated by dimethylbenzanthracene (DMBA) and promoted by croton oil. Tricaprylin was not teratogenic in mice or rats, but some reproductive effects were seen in rabbits. A low level of fetal eye abnormalities and a small percentage of abnormal sperm were reported in mice injected with Trioctanoin as a vehicle control. Clinical tests of Trilaurin at 36.3% in a commercial product applied to the skin produced no irritation reactions. Trilaurin, Tristearin, and Tribehenin at 40%, 1.68%, and 0.38%, respectively, in commercial products were also negative in repeated-insult patch tests. Tristearin at 0.32% in a commercial product induced transient, mild to moderate, ocular irritation after instillation into the eyes of human subjects. Based on the enhancement of penetration of other chemicals by skin treatment with glyceryl triesters, it is recommended that care be exercised in using them in cosmetic products. On the basis of the available data, the following 23 glyceryl triesters are considered safe as used in cosmetics: Trilaurin, Triarachidin, Tribehenin, Tricaprin, Tricaprylin, Trierucin, Triheptanoin, Triheptylundecanoin, Triisononanoin, Triisopalmitin, Triisostearin, Trilinolein, Trimyristin, Trioctanoin, Triolein, Tripalmitin, Tripalmitolein, Triricinolein, Tristearin, Triundecanoin, Glyceryl Triacetyl Hydroxystearate, Glyceryl Triacetyl Ricinoleate, and Glyceryl Stearate Diacetate. Some of these are not currently in use, but would be considered safe if used at concentrations similar to those glyceryl triesters that are in use as cosmetic ingredients.

Animals↗
PubMed1997

Combined effects of sphingomyelin and cholesterol on the hydrolysis of emulsion particle triolein by lipoprotein lipase.

Sphingomyelin (SM) is one of the major lipids in lipoproteins. However, its function in lipoprotein metabolism is unknown. In an attempt to understand the role that this lipid plays in modulation of lipoprotein lipase (LPL)-mediated hydrolysis, triolein-based emulsion particles containing 15% (physiological concentration) and 30% of the phospholipid content as SM together with phosphatidyl choline were used as substrate for the enzyme. Using a continuous fluorescence displacement assay to measure triglyceride (triolein) hydrolysis, it is shown that LPL activity was not modified by physiological concentrations of SM. However, under these assay conditions the presence of 30% SM inhibited LPL hydrolysis. SM and cholesterol (a normal component of the lipoprotein surface monolayer) become closely associated in phospholipid monolayers and bilayers. Incorporation of cholesterol into emulsion particles containing only PC increased LPL activity, but this increase was reduced by the additional presence of a physiological concentration (15%) of SM. These model studies suggest that the ratio, cholesterol:SM, in the monolayer may regulate the hydrolytic activity of the LPL. The production of ceramide by sphingomyelinase pre-treatment of emulsion particles containing SM leads to a two- to three-fold increase in LPL activity. This effect was dependent on sphingomyelinase concentration and time of pre-incubation and was not seen with cholesterol containing substrates. The ability of apolipoprotein CII to enhance LPL-catalysed triolein hydrolysis was not affected by the presence of SM; however, the stimulatory effect of this apolipoprotein was attenuated by pre-treatment of emulsion particles with sphingomyelinase. In summary, physiological concentrations of SM can inhibit the hydrolysis of cholesterol-containing emulsion particles; while pre-treatment of SM containing emulsion particles with sphingomyelinase in the absence of cholesterol can increase LPL-mediated triglyceride hydrolysis.

Animals↗
PubMed2001

Monitoring priority pollutants in a sewage treatment process by dichloromethane extraction and triolein-semipermeable membrane device (SPMD).

Semipermeable membrane devices containing a neutral lipid triolein (triolein-SPMD) and conventional dichloromethane extraction were used to monitor the presence and concentrations of priority organic pollutants in a sewage treatment process in Beijing, China. Both samples gave similar information on the presence of target PCB congeners, PAHs, Organochlorine pesticides and substituted benzenes in sewage at all sites. After 20 days' sampling, the concentrations of contaminants in triolein of SPMD were much higher than those in dichloromethane extracts, which resulted in easier analysis, improved the detection limits, and increased the accuracy. Previous field mean sampling rates for SPMD were used to estimate concentrations of PCB congeners in sewage, which compared to their determined concentrations by dichloromethane extraction. The consistency and superiority of SPMD technology were proved for the detection of priority organic contaminants from sewage. Lower removal rates for PCB congeners and PAHs coincided with the persistence of them in environment. More attention should be paid to urban sewage treatment process adopting activated-sludge method, where priority organic pollutants might not be removed, even present higher concentrations after treatment.

Environmental Monitoring↗
PubMed2006

Structural study on polymorphism of cis-unsaturated triacylglycerol: triolein.

To clarify the influence of cis-unsaturation on solid-state structures of triacylglycerols (TAGs), the crystal structures of three crystalline phases (alpha, beta' and beta) of triolein [C3H5(OCOC17H33)3] were investigated by powder X-ray diffractometry and IR and Raman spectroscopy. The influence on the structural change of the alpha phase in the course of cooling was also studied. With respect to the subcell structure and conformational order of hydrocarbon chains in the beta and beta' phases, triolein resembles saturated TAGs; trans-zigzag hydrocarbon chains are adopted in the T(parallel) subcell for the beta phase and in the O(perpendicular) subcell for the beta' phase. The influence of cis-unsaturation was most obvious in the structure of the alpha phase and its temperature dependence. The alpha phase of triolein does not form the ordinary hexagonal subcell but a rather loose distorted subcell, which hardly changes in cooling, forming a striking contrast to the hexagonal-->pseudohexagonal subcell transformation found in the alpha phase of saturated TAGs.

Crystallization↗