Bonded-phase Capillary Column Research Articles

The Effects of Frying Time and Temperatures on Fatty Acids Profile of Blanched Potato Chips

The aim of this research was to study whether the frying time and temperature affected fatty acids profiles of blanched potato chips. Factorial designs were carried out using a completely randomized design (CRD) two factor (time and temperature) and three levels with two replications. Frying temperature was set up at 160 0C, 180 0C and 200 0C. The potato chips were fried for 3, 5, 7 minutes. The oil type used was sunflower. The fatty acids profiles were analyses with capillary gas liquid chromatography (Varian 3400) equipped with an auto sampler and a flame ionization detector (FID) using a 50 m x 0.32 mm (I.D) fused silica bonded phase capillary column (BPX70, SGE, Melbourne, Australia). The experiments were run in duplicate and the present results are the average of the obtained values. ANOVA analysis of the results was carried out using SPSS software (version 11, 2004). The key plot software for making three dimensions was the sigma plot scientific graphing software.
 The results showed moisture content and colour index of blanched potato chips decreased significantly with increasing frying time and temperature. Furthermore, unsaturated fatty acids (cis oleic and linoleic) decrease after long period frying.

Capillary electrochromatographic separation of metal ion species with on-line detection by inductively coupled plasma mass spectrometry

A bonded phase capillary column containing macrocyclic polyamine, [28]ane-N6O2 functional groups was used for the electrophoretic separation of arsenic, chromium and selenium species. A simple device interfacing this capillary electrochromatography (CEC) systems to an inductively coupled plasma mass spectrometer (ICPMS) is described. The dimension of the capillary column was 160cm×100μm i.d. To accommodate this electrophoretic separation, an auxiliary capillary was used with nitric acid (0.05M) as makeup liquid. With the electrokinetic method at –20kV, 20s and a nebulizer gas flow rate of 1lmin−1, the sample injected was analyzed with an applied potential of −20kV. The background electrolyte buffer for the separation of CrO42−–Cr3+ was phosphate (20mM, pH 6.5). That for HAsO42−–Ph4As+ was pyromellitate (20mM, pH 6.0) and for SeO42−–SeO32− was acetate (20mM, pH 6.0). The role of the buffer’s anion was also discussed. The separation efficiency of the bonded phase was compared with the bare fused silica. Concentration detection limits for these metal ions were in the low ppb range. In addition, the matrix effect of the established system with the bonded phase was found smaller than that with the bare fused silica.

Macrocyclic polyamine as a selective modifier in a bonded-phase capillary column for the electrophoretic separation of aromatic acids

The use of a macrocyclic polyamine, 28[ane]-N 6O 2, as a selective modifier in a bonded-phase capillary column for the electrophoretic separation of 14 aromatic acids is described. Parameters that affect the performance of the separations, such as the type of buffer, the pH and concentration of buffer, the applied potential and the injection mode were studied. By changing the buffer pH (4.0–5.0), buffer concentration (10–50 m M) and applied potential (−10∼−20 kV), optimum conditions were obtained at −20 kV, using an acetate buffer (20 m M, pH 4.5), hydrodynamic injection with a vacuum at the buffer reservoir on the detector side and detection at 220 nm. The results showed that the separation was effective under these conditions. The plate number was greater than 4·10 4 m −1. Due to the wide variation in the mobilities of the test compounds, injection studies suggested that a vacuum at the buffer reservoir on the detector side would produce a result that is more representative of the initial sample composition. Benzoic acid in soy sauce, salicylic acid in Salic ointment and Aspirin were sampled and analyzed using the established conditions.

Quantitative metabolic profiling of testicular steroid secretions with bonded-phase capillary gas chromatography.

A procedure is described for quantitative metabolic profiling of nine steroids secreted by mouse testes. The procedure incorporates Celite column chromatography and a gas chromatograph equipped with a bonded-phase capillary column. Validation tests demonstrated that the procedure is precise, efficient, sensitive, and capable of providing information about the spectrum of steroids secreted by testes perfused in vitro. The procedure was used to determine the effect of the hemimelic extra toes gene mutation on the steroidogenic potential of inbred mouse testes perfused in vitro.

Capillary electrophoresis and supercritical chromatography, complementary and alternative techniques for the determination of urinary metabolites of styrene

Two analytical methods without an extraction step were developed using capillary electrophoresis and supercritical fluid chromatography in order to determine phenylglyoxylic (PGA) and mandelic (MA) acids in urine, with minimum treatment and manipulation of biological samples. The urine was diluted ten-fold in acetonitrile and directly injected into the analytical systems after centrifugation. Analysis was performed by capillary electrophoresis on alkyl bonded phase capillary columns with sodium formiate (4·10 −2 M)-isopropanol (9:1, v/v) as a buffer, and by supercritical fluid chromatography on a Diol bonded phase silica column with ethanol-water-methanesulphonic acid (97.5:2.4:0.1, v/v) as coeluent of CO 2. Detection of PGA and MA was performed by ultraviolet detection at 255 and 210 nm, respectively. The methods are in agreement, and are easily able to detect 5 mg/g creatinine for PGA, and 15 mg/g creatinine for MA, which are one twentieth of the lowest biological exposure index values.

Rapid and sensitive procedure for the separation and quantitation of D- and L-serine in rat brain using gas chromatography-mass spectrometry.

A very simple and rapid GC-MS procedure for the separation and quantitation of D- and L-serine has been developed utilizing a conventional bonded-phase capillary column. The procedure involves initial esterification with isobutanol followed by acylation with the chiral derivatizing reagent S-(-)-N-(heptafluorobutyryl)prolyl chloride (HPC). This procedure requires neither extraction nor clean-up steps and is sensitive to 50 pg on-column. Total time of the procedure is under 3 h and derivatives are stable at room temperature for at least 5 days, making this procedure ideal for automated injections. A simple, one-day synthesis of HPC is described which yields > 99.9% optical purity.

Fast evaluation of the polarity of gas chromatographic columns using the difference in apparent carbon number of linear alkanes and alcohols with the same retention

A method for the measurement of the polarity order of gas chromatographic columns (liquid-packed, porous polymer beads, capillary) which does not require reference to standard phases and many probes, is suggested. The method is based on Δ C, i.e. the difference in apparent carbon number of linear alkanes and alcohols with the same retention time. The graphical measurement or mathematical calculation of the horizontal distance between the straight lines obtained by plotting the logarithm of the retention of linear alkanes and alcohols as a function of their number of carbon atoms allows the importance of hydrogen bonding with respect to the dispersion forces to he evaluated. All the retention data (adjusted retention times and volume, relative retention, adjusted, net and specific retention volumes) can be used for the calculations. The method is useful for the determination of the change in polarity of mixed or serially linked columns, for the evaluation of the performance of porous polymer beads with respect to liquid stationary phases and for the comparison of packed and bonded-phase capillary columns when polyglycol or polydimethylsiloxane phases are used.

Chromatographic techniques in inborn errors of metabolism

Chromatography has played a pivotal role in the advances made during the last 30 years in our knowledge of inborn errors of metabolism. This review discusses the application of some of these techniques to the analysis of organic acids and acylcarnitines. The separation of organic acids needed a comprehensive approach that would permit all of the many organic acids present in urine or other complex mixtures to be extracted, analysed and identified in a single run. This required analytical methods of great resolving power, wide linear range and universal detectors such as gas chromatography (GC), or GC coupled with mass spectrometry. Sample preparation was another problem that has been tackled by a variety of approaches. Organic solvents have been employed widely for the extraction of organic acids from physiological fluids. Unfortunately, recoveries of the different organic acids by this method are sometimes less than quantitative and variable depending on the compound. Other methods, such as the use of DEAE-Sephadex columns, have the advantage of resulting in close to 100% recoveries, but are more tedious. Liquid partition chromatography on short silicic acid columns has also been recommended as a useful clean-up step prior to GC, permitting both the identification and quantitation of organic acids in urine, plasma or amniotic fluid. Although many derivatization procedure have been used to prepare organic acids for gas chromatography, the most common is trimethylsilylation. Oxo acids are usually reacted with one of several commonly used reagents to form oximes. GC analysis of organic acids was initially done using packed columns with methylsilicone-based, non-polar stationary phases.(ABSTRACT TRUNCATED AT 250 WORDS)

Study of fatty acid profiles in cancer cells grown in culture using gas chromatography-mass spectrometry

The determination of long-chain fatty acids in the phospholipid, triglyceride and free fatty acid fractions of HT29/219 colon cancer cells grown in a medium containing either foetal calf serum or horse serum, was carried out using gas chromatography - mass spectrometry. Several bonded-phase capillary columns were tested for the separation of the fatty acid methyl esters, and a 30-m poly(ethylene glycol) column was found to give optimum separation. The mass spectrometer was set to the multiple ion detection mode to increase the sensitivity of the recording of the characteristic ions, consisting of the molecular ion and the base peak. The phospholipid and triglyceride compositions of the cells were different when the cells were grown in media containing different sera. Differences were also found in the turnover of the acids in the different lipid fractions, the phospholipids being the most important, when the cells were grown in different media. The cellular metabolism and turnover of certain fatty acids differed from others in the same cell. These differences emphasise the importance of a precise knowledge of the lipid composition of the culture medium in in vitro studies of cancer cells.

Evaluation of high-performance liquid and capillary gas chromatography for analysis of sesquiterpene lactones of the Melampodiinae

The capacity of reversed-phase high-performance liquid chromatography (HPLC) and capillary gas chromatography (GC) to separate 37 sesquiterpene lactones of the Melampodiinae has been investigated. The HPLC system employed a Hypersil ODS column and methanol-water as eluent for isocratic and gradient separations. The GC system utilized a RSL-150 bonded phase capillary column with flame ionization detection. The previously characterized melampolide melnerin B was determined by both HPLC and GC to be a mixture of two isomers, containing a 2-methylbutanoate (melnerin B) or a 3-methylbutanoate (melnerin B′) substituent at C-8. The HPLC and GC methods developed have been applied to the analysis of a crude extract of Melampodium cinereum.

Quantitative analysis for organic acids in biological samples: batch isolation followed by gas chromatographic-mass spectrometric analysis.

This new method for qualitative and quantitative determination of organic acids, aldehydes, and ketones in biological samples is effective for use with urine, plasma, and amniotic fluid, and it requires no deproteinization. Isolation by batch-wise liquid partition chromatography on silicic acid follows formation of the O-(2,3,4,5,6-pentafluorobenzyl)oximes of oxoacids, aldehydes, and ketones. The total organic acid content of the sample provides a rapid screening test for metabolic abnormality. A wide-bore, bonded-phase capillary column was used for quantitative gas chromatographic-mass spectrometric analysis, followed by automated identification and quantification. Analytical recoveries were quantitative for a wide variety of metabolites. Gas-chromatographic retention indices, discriminating ions, and control ranges in amniotic fluid, plasma, and urine of adult subjects were determined for 61 biologically important compounds.

Determination of nitroglycerin in human plasma using bonded-phase capillary column gas chromatography with electron-capture detection

Determination of nitroglycerin in human plasma using bonded-phase capillary column gas chromatography with electron-capture detection

Gas Chromatographic Analysis of Nuclear Fuel Reprocessing TRUEX-CCI4 Process Solvent

A gas chromatographic method using a bonded-phase capillary column is described to quantitatively analyze for tributyl phosphate and octyl(phenyl)-N,N-diisobutyl-carbamoylmethylphosphine oxide in a transuranic extraction (TRUEX)—carbon tetrachloride process solvent. This solvent is being developed for use in removing transuranic elements from high-level liquid waste generated at nuclear fuel reprocessing plants.

A new gas chromatographic retention index for pesticides and related compounds

AbstractA new gas chromatographic (GC) retention index based on a homologous series of tri‐n‐alkylamines is proposed for use in the detection of pesticides and related compounds because the standard n‐paraffin hydrocarbons used for the Kovats index do not show up well on the nitrogen‐phosphorus detectors commonly used in pesticide analysis. Using fused silica bonded phase capillary columns (DB‐1 or DB‐5), the trialkylamine indices of 106 selected pesticides and related compounds were measured and their relationship to the Kovats index determined.

Quantitative metabolic profiling of testicular steroid secretions with bonded-phase capillary gas chromatography

A procedure is described for quantitative metabolic profiling of nine steroids secreted by mouse testes. The procedure incorporates Celite column chromatography and a gas chromatograph equipped with a bonded-phase capillary column. Validation tests demonstrated that the procedure is precise, efficient, sensitive, and capable of providing information about the spectrum of steroids secreted by testes perfused in vitro. The procedure was used to determine the effect of the hemimelic extra toes gene mutation on the steroidogenic potential of inbred mouse testes perfused in vitro.

Determination of pentazocine (Fortral R) in human urine: Gas chromatographic-mass spectrometric investigations

After oral application of the central acting analgesic Pentazocine (Fortral R) besides the unchanged drug some further excretion products were detected in human urine by GLC/MS. For their identification E.I. - and C.I. - M.S. as well as the just recently available FAB ( F ast A tom B ombardment)-technique were employed. All analyses were performed on a VG-Micromass 7035; the samples were introduced in the ion source via a fused silica, bonded phase capillary column (30 meters; DB-1 J+W Scientific, Inc.). The analytical profiles of the pure substance and some metabolites are reported as well as the behaviour of the pure substance on acid hydrolysis.

Trace gas chromatographic analysis by use of large sample on-column injection with bonded phase capillary columns

Trace gas chromatographic analysis by use of large sample on-column injection with bonded phase capillary columns

Detection of pentazocin (Fortral) in human urine: gas chromatographic/mass spectrometric studies

After oral application of pentacozine (Fortral) besides the unchanged drug some further excretion products were detected by glc/ms in human urine. For their identification e.i.-and c.i.-mass-spectrometry as well as the just recently available FAB-technique were employed. All analyses were performed on a VG-Micromass 7035; the samples were introduced in the ion source via a fused silica, bonded phase capillary column (30 metres; DB-1 J + W, Inc.). The analytical profiles of the pure substance and some metabolites are reported as well as the behaviour of the pure substance on acidic hydrolyzation.