Determination of total cholesterol in meat and poultry by gas chromatography: single-laboratory validation

The primary objective of this study was to determine the intralaboratory performance of a cholesterol determination method that combines direct saponification of a 1 g meat or poultry sample and GC quantification of liberated cholesterol without derivatization. Cholesterol was detected at 11.96 min using a GC-flame ionization detector (FID) system. With a 0.005 mg/mL 5alpha-cholestane internal standard and 0.008 to 0.020 mg/mL cholesterol standard series, the FID response was linearly correlated to standard concentrations with a coefficient of determination of 0.995 and a response factor of 0.66. The LOD and LOQ were 1.24 and 4.00 mg/100 g, respectively. Cholesterol could be analyzed within 6 days of preparation with high precision (CV of 0.92 to 2.69%) and accuracy (recovery of 93.24 to 100.56%). This simplified procedure allows for decreased errors and increased productivity, and the method proved to be reliable and able to withstand practical variation in procedural application. The method has been applied routinely with excellent precision to update data on the cholesterol content of beef, pork, and chicken in the U.S. Department of Agriculture National Nutrient Database for Standard Reference.     

Identification of the chlorination products of aliphatic ketones by gas chromatography and gas chromatography/mass spectrometry

The differences in the gas chromatographic retention indices of the chlorination products of aliphatic ketones and parent carbonyl compounds (ΔRI) are constant, and their numeric values depend on the number and position of chlorine atoms in the molecule. A simplest version of an additive scheme for the evaluation of retention indexes is developed to identify the chloro derivatives of carbonyl compounds. The order of the chromatographic elution of diastereomeric α,α′-dichloro-k-alkanones (k > 2) is found.     

Identification of gasoline contamination of ground-water by gas chromatography.

Individual components that make up different grades of gasoline - or gasolines of the same grade produced by different manufacturers - are resolved and identified by gas chromatography using packed columns and a flame ionization detector. Contaminants at levels as low as 0.5 mu1/1 may be identified by the method if samples of gasoline from the source of contamination can be obtained for comparison. The uniqueness of this method is that it can be applied for routine analysis without the use of sophisticated complements for the gas chromatograph.     

顶空气相色谱法快速测定肉及肉制品中乙烯利的残留量

利用乙烯利在碱性水溶液中受热能够快速分解成乙烯的特性,建立了顶空气相色谱法快速测定乙烯利在肉及肉制品中残留量的方法。在样品中添加碱液后恒温加热,吸取顶空瓶中的上层气体,采用石英毛细管色谱柱分离,氢火焰离子化检测器测定。该方法的检测限为0.01mg/kg,回收率为90.9%～96.0%,相对标准偏差为3.5%～8.5%。适用于猪肉、牛肉、鸡肉等肉及肉制品中乙烯利残留量的检测。     

Determination of three nitroimidazole residues in poultry meat by gas chromatography with nitrogen-phosphorus detection.

A method was developed for the determination of the nitroimidazole compounds dimetridazole (DMZ), ronidazole (RNZ) and metronidazole (MNZ) by gas chromatography with nitrogen phosphorus detection. Nitroimidazole compounds were extracted with acetonitrile, followed by acidification using acetic acid and cleanup using strong cation-exchange (SCX) SPE column. Validation in chicken muscle fortified at a concentration of 5 microg/kg gave mean recoveries of 85% DMZ, 90% RNZ, 80% MNZ with RSDs of 13.0, 14.3, 11.2%, respectively (n=6). The method is suitable for statutory residue testing and is used as a quick screening method in the National Residue Surveillance Plan in China.     

Identification of the phenothiazines by gas chromatography of their pyrolysis products

Summary Nineteen phenothiazines were pyrolyzed and their products analyzed gas chromatographically. The pyrolysis products were compared with those obtained from a similar study of the barbiturates. Tentative identifications have been made of three pyrolysis products. The pyrolyzates of the various phenothiazine derivatives yield gas chromatographie patterns which differentiate among them.

---

Zusammenfassung Die Pyrolyseprodukte von 19 Phenothiazinen wurden gaschromato-graphisch analysiert und mit jenen verglichen, die bei einer analogen Untersuchung von Barbituraten erhalten worden waren. Die Identifizierung von drei Pyrolyseprodukten wurde versucht. Die Pyrolysate der verschiedenen Phenothiazinderivate lassen sich gaschromatographisch unterscheiden.

---

Résumé On a effectué la pyrolyse de dix-neuf phénothiazines et analysé les produits résultants par chromatographie en phase gazeuse. On a comparé les résultats — ceux obtenus au cours d'une étude semblable sur les barbiturates. On a tenté d'identifier trois produits de pyrolyse. Les produits de pyrolyse de plusieurs dérivé de la phénothiazine donnent en chromatographie en phase gazeuse des enregistrements qui permettent de les différencier.

---

---

Dedicated to Prof.A. A. Benedetti- Pichler on the occasion of his 70th birthday.     

Identification of bromination products of chloro-substituted anilines in aqueous environment by gas chromatography

To reduce the detection limits of aniline and its various chloroderivatives (all isomers of mono- and dichloroanilines, 2,4,5 -, 2,4,6-, and 3,4,5-trichloroanilines, pentachloroaniline) in aqueous media we suggested bromination reaction, followed by gas chromatographic definition bromo derivatives of chloroanilines on a selective electron capture detector. To identify the products of bromination of chloroaniline in combination with mass-spectrometric data we used chromatographic retention indices on standard nonpolar polydimethylsiloxane stationary phase that was determined for 50 compounds in this class. The technique of identifying bromoderivatives of chloroaniline in water was developed at the gas-chromatographic analysis in the selective electron capture detector. To improve the reliability of the identification of additional bromoderivatives of chloroanilines we obtained their trifluoroacetyl derivatives.     

Identification of oxygenated polycyclic aromatic hydrocarbons in diesel particulate matter by capillary gas chromatography and capillary gas chromatography/mass spectrometry

Summary Using a two-step liquid chromatographic separation on normalphase cartridges, crude extracts of diesel particulate matter can be separated without time-consuming sample handling into special fractions which mainly contain slightly-polar oxygenated polycyclic aromatic hydrocarbons (oxy-PAH) and nitrated polycyclic aromatic hydrocarbons (nitro-PAH). Subsequent analysis was by fused-silica capillary gas chromatography on a SE54 column along with flame-ionisation (GC/FID) and positive-ion electron-impact mass spectrometric detection (GC/MS) respectively. A number of individual oxy-PAH belonging to four different chemical classes (ketones, quinones, anhydrides and aldehydes) and several individual nitro-PAH were characterized by their retention times and mass spectra. Presented at the 15th International Symposium on Chromatography, Nürnberg, October 1984     

Comparative investigation of irradiated meat by the methods of electron paramagnetic resonance and gas chromatography

A comparative study of irradiated pork meat containing bone was made by the methods of electron paramagnetic resonance (EPR) and gas chromatography (GC). In this investigation EPR has the advantage to be a very fast and unambiguous method even in the cases of thermal treatment of bones. On the other hand, GC analysis is a time consuming procedure however, it becomes very valuable for meat samples that contain no bones.     

气相色谱-质谱联用快速检测毛豆中103种农药多残留

建立了固相萃取-气相色谱-质谱法快速检测毛豆中103种农药多残留的分析方法.样品用乙腈-水溶液均质提取,经盐析除水液液分配,Envi-18和PSA串联柱净化后用气相色谱-质谱仪(GC-MS)分析.采用选择离子扫描方式,外标法定量.方法的检出限(S/N=3)为0.001～0.021 mg/kg,在加标水平为0.2 mg/kg时,方法回收率为74%～123%,相对标准偏差为3.1%～13%.     

Identification and quantification of the constituents of madder root by gas chromatography and high-performance liquid chromatography

The possibilities in the identification and quantitation of the constituents of Rubia tinctorum L.'s root, called also madder root, was described and compared by gas chromatography (GC)-MS, high-performance liquid chromatography (HPLC)-UV/photodiode array detection (DAD) and HPLC-MS: chromatographic analyses were carried out in parallel, from the same samples/extracts/hydrolyzates. Anthraquinone glycosides, anthraquinones, carboxylic acids and sugars were determined directly in the presence of the matrix and in its extracts without and subsequently to hydrolyses. Hydrolyses were performed as a function of time, with hydrochloric and trifluoroacetic acids, as well as enzymatically. Data revealed that as hydrolyzing agent trifluoroacetic acid is to be preferred. Madder root's anthraquinones (pseudopurpurin/purpurin, alizarin, lucidin, munjistin, nordamnacanthal) were identified on the basis of their absorption spectra (HPLC-DAD) and fragmentation patterns by GC-MS and HPLC-MS, equally. Reproducibility of anthraquinone's quantitation, by HPLC-DAD and GC-MS, in the concentration ranges of 4 x 10(-5) to 3 x 10(-2)g/g dried sample, provided an average reproducibility of 4.2% (varying between 0.9 and 9.4% relative standard deviation (RSD percentages)). Carboxylic acids (malic, citric, quinic, rosmarinic acids) and saccharides (xylose, ribose, fructose, glucose, sucrose, primverose) were quantified as their trimethylsilyl (oxime) ether/ester derivatives by GC-MS, in the concentration ranges of 10(-5)g to 10(-2)g/g dried sample, with an average reproducibility of 4.7% RSD.     

Identification of stilbene derivatives by paper and gas chromatography and paper eleetrophoresis

Summary Some stilbene derivatives have been identified by using paper chromatography in five different solvents systems, paper electrophoresis in two different electrolytes, and gas chromatography to detect cleavage products.

---

Zusammenfassung Einige Stilbenderivate wurden chromatographisch mit fünf verschiedenen Lösungsmittelsystemen identifiziert, elektrophoretisch in zwei verschiedenen Elektrolyten und gaschromatographisch unter Nachweis der Spaltprodukte.

---

Résumé On a identifié quelques dérivés du stilbène par Chromatographie sur papier dans 5 systèmes différents de solvants, par électrophorèse (sur papier) dans deux électrolytes différents et par Chromatographie en phase gazeuse pour déceler les produits de coupure.

---

---

Dedicated to the 60th birthday of Prof. Dr.M. Jureek, Dr. Sc.