Determination of UV-absorbing anions in environmental samples by microcolumn high-performance liquid chromatography

The Chromatographic retention and separation of NO ₂ ^- , Br^-, NO ₃ ^- , and I^- anions on a column packed with Nucleosil 100-5 C18 dynamically modified with trimethyloctadecylammonium bromide (TMODAB) was studied using direct UV detection. A procedure was developed for the determination of the above anions in the concentration range 0.06-2500 Μg/L without preconcentration. Sample preparation involved only the elimination of organic impurities (if present) from the test sample. The procedure was used for the determination of NO ₂ ^- and NO ₃ ^- anions in Baikal Lake water and in an aerosol extract.     

Determination of traces of inorganic anions by means of high-performance liquid chromatography on zipaxsax columns

Zipax-SAX pellicular beads are used as the anion-exchanger material ; a high-pressure packing technique is described. A Zipax-SAX column (200 × 4.5 mm) is used in a separation system with eluent suppression and conductivity detection as in ion-chromatography. Good separation of chloride, nitrite, bromide, nitrate and sulfate is obtained with 1.4 × 10^-3 M succinate or adipate eluents at pH 7. A complete separation takes about 6 min at a flow rate of 3 ml min^-1. Detection limits of 2 μg l^-1 chloride, 4 μg l^-1 nitrate and 10 μg l^-1 sulfate can be reached if 2 ml of sample is preconcentrated.     

Determination of thiamine by high-performance liquid chromatography

High-performance liquid chromatographic methods for the determination of thiamine (vitamin B1) in foodstuffs or biological tissues and fluids are outlined and discussed. The methods are often similar and interchangeable, sample extraction and clean up procedures being the major difference. Most of the methods use either ultraviolet or fluorescence detection. Fluorescence detection requires either precolumn or postcolumn oxidation of thiamine to thiochrome. A number of methods are recommended and problems with standardization are emphasized.     

Determination of aprotinin by high-performance liquid chromatography

Summary A highly accurate and reproducible method for the determination of aprotinin (bovine pancreatic trypsin inhibitor) by HPLC is described. In the experiments, the relative standard deviation was 1.2% and detection limit 1 FIP-U cm^–3. Also, the method is quick and selective and active ingredients from difference source correlate well with enzymatic method. Analyses at different laboratories can be compared directly.     

高效液相色谱法测定硫酸沙丁胺醇

利用高效液相色谱仪-电子捕获检测器(HPLC-ECD)测定了市售片剂硫酸沙丁胺醇的含量.结果表明,利用HPLC-ECD技术测定硫酸沙丁胺醇的线性范围为0.944~33.8mg·L-1(r=0.999 6);回收率为99.0%~107.8%(RSD≤4.6%).该法可用于测定片剂的硫酸沙丁胺含量.     

Determination of ephedra alkaloids by high-performance liquid chromatography

Summary Two simple methods were developed for the simultaneous determination of six alkaloids (ephedrine, pseudoephedrine, norephedrine, norpseudoephedrine, methylephedrine and methyl-pseudoephedrine) inEphedrae Herba by high-performance liquid chromatography. The first method was carried out by using a Cosmosil 5C₁₈-MS column with a gradient solvent system consisting of a phosphate buffer and acetonitrile, and detection at 210 nm. The contents of alkaloids in non-pretreated ephedra herb extracts could be determined easily in 50 min. Alternatively, the alkaloids could be determined within 35 minutes by using a Cosmosil 5C₁₈-MS column with an isocratic solvent system of a sodium dodecyl sulfate-acetonitrile solution. The two methods are compared and discussed.     

Determination of beta-carbolines in foodstuffs by high-performance liquid chromatography and high-performance liquid chromatography-mass spectrometry

A high-performance liquid chromatographic method combined with fluorimetric detection is described for the determination of beta-carboline (norharman) and 1-methyl-beta-carboline (harman). The analysis of foodstuffs for the identification of beta-carbolines is facilitated by clean-up samples using Bond Elut PRS cartridges. Recoveries were excellent. Further, a high-performance liquid chromatographic-mass spectrometric method was also developed for their identification. The concentration of beta-carboline among the foodstuffs and alcoholic beverages varied greatly. Also, norharman and harman were observed in uncooked foodstuffs, whereas acetaldehyde was found in most fermented food. The toxicological implication of beta-carbolines in foodstuffs is discussed.     

Determination of tetracyclines in plasma by high-performance liquid chromatography

A new method for the separation and quantitative determination of certain anti-biotics of the tetracycline series in blood plasma by high-performance liquid chromatography on a column filled with Partisil PXP 5 silica gel is described.I. M. Sechenov First Moscow Medical Institute. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 376–379, May–June, 1981.