ABSTRACT
A sensitive analytical method has been developed in order to identify and quantify major drugs of abuse (DOA), namely morphine, codeine, 6-monoacetylmorphine, cocaine, ecgonine methyl ester, benzoylecgonine, amphetamine, methamphetamine, methylenedioxymethamphetamine and methylenedioxyamphetamine in human hair. Samples of hair were extracted with methanol under ultrasonication at 50°C after a three step rinsing process to remove external contamination and dirt hair. Derivatization with BSTFA was selected in order to increase detection sensitivity of GC/MS analysis. Optimization of derivatization parameters was based on experiments for the selection of derivatization time, temperature and volume of derivatising agent. Validation of the method included evaluation of linearity which ranged from 2 to 350ng/mg of hair mean concentration for all DOA, evaluation of sensitivity, accuracy, precision and repeatability. Limits of detection ranged from 0.05 to 0.46ng/mg of hair. The developed method was applied for the analysis of hair samples obtained from three human subjects and were found positive in cocaine, and opiates.
Subject(s)
Gas Chromatography-Mass Spectrometry/methods , Hair/chemistry , Illicit Drugs/analysis , Substance Abuse Detection/methods , Humans , Limit of DetectionABSTRACT
The analysis of amino acids has become a central task in many aspects. While amino acid analysis has traditionally mainly been carried out using either gas chromatography (GC) in combination with flame ionization detection or liquid chromatography (LC) with either post-column derivatization using ninhydrin or pre-column derivatization using o-phthalaldehyde, many of today's analysis platforms are based on chromatography in combination with mass spectrometry (MS). While derivatization is mandatory for the GC-based analysis of amino acids, several LC platforms have emerged, particularly in the dawn of targeted metabolite profiling using hydrophilic interaction liquid chromatography (HILIC) coupled to MS, allowing the analysis of underivatized amino acids. Among the numerous analytical platforms available for amino acid analysis today, we here compare three prominent approaches, being GC-MS and LC-MS after amino acid derivatization using chloroformate and HILIC-MS of underivatized amino acids. We compare and discuss practical issues as well as performance characteristics, e.g., the use of (13)C-labeled internal standards, of the different platforms and present data on their practical implementation in our laboratory. Finally, we compare the real-life applicability of all three platforms for a complex biological sample. While all three platforms are very-well suited for the analysis of complex biological samples they all show advantages and disadvantages for some analytes as discussed in detail in this manuscript.
Subject(s)
Amino Acids/analysis , Chromatography, Liquid/methods , Gas Chromatography-Mass Spectrometry/methods , Amino Acids/chemistry , Calibration , Carbon Isotopes/chemistry , Chemistry Techniques, Analytical , Flame Ionization/methods , Formates/analysis , Hydrophobic and Hydrophilic Interactions , Ions , Limit of Detection , Ninhydrin/chemistry , Protein Hydrolysates , Reproducibility of Results , o-Phthalaldehyde/chemistryABSTRACT
Buspirone is an anxiolytic agent that appears to have no sedative effects. The aim of this study was to assess the effects of buspirone on breathlessness and exercise tolerance in patients with chronic airway obstruction. Sixteen patients, age 56.9 +/- 17.0; forced expiratory volume in 1 s (FEV1) 1.15 +/- 0.42 l; FEV1/forced vital capacity (FVC) 50.7 +/- 15.0%; PaCO2 42.2 +/- 5.5 mm Hg; and PaO2 57.6 +/- 10 mm Hg, underwent a 6-min walking test, an incremental cycle ergometer test, an incremental treadmill walking test with self-assessment of dyspnea on Borg's scale during exercise and an assessment of respiratory drive (P 0.1), timing [inspiration time (TI)/total breathing time (Ttot)], PaO2, PaCO2, FVC, FEV1, following oral administration for 14 days of placebo or buspirone (20 mg daily) in a double-blind, cross-over randomized way. We also used the symptom check list-90-R for the assessment of subjective complaints and symptomatic behavior. A significant improvement in anxiety, depression and obsessive symptoms and complaints was noted after buspirone treatment. The P 0.1, TI/Ttot, arterial blood gases and respiratory mechanics did not change after drug treatment. There was an improvement in exercise tolerance and in the sensation of dyspnea during the buspirone period. Thus, as given in this study, oral buspirone has therapeutic potential in the treatment of dyspnea in patients with chronic lung disease.
Subject(s)
Buspirone/therapeutic use , Dyspnea/physiopathology , Exercise Tolerance , Lung Diseases, Obstructive/drug therapy , Adult , Aged , Double-Blind Method , Dyspnea/etiology , Forced Expiratory Volume , Humans , Lung Diseases, Obstructive/complications , Lung Diseases, Obstructive/physiopathology , Middle Aged , Vital CapacityABSTRACT
Ethanol at concentrations up to 5% (v/v) had no effect on the growth of Schizosaccharomyces pombe, whereas concentrations over 7.5% were inhibitory. The major membrane phospholipids in S. pombe cells growing aerobically in the absence of added ethanol were phosphatidylinositol, phosphatidylcholine and phosphatidylethanolamine. Oleic acid (18:1) was the main fatty acid. When ethanol (7.5%) was added to aerobically growing cultures, the phosphatidylinositol content increased, whereas the 18:1 content decreased. Similar changes were observed in the membrane phospholipids of cells grown anaerobically without ethanol. However, the presence of ethanol in anaerobically growing cultures had an opposite effect on fatty acids, as the 18:1 content increased. The results support the idea that ethanol tolerance in S. pombe may be connected with a high content of 18:1 fatty acids, and with the ability to maintain a high rate of phospholipid biosynthesis.
