HP-5 Column Research Articles

Ionic liquid-functionalized pillar[6]arene: A novel stationary phase of high selectivity towards a wide range of isomers

In this work, a novel pillar[6]arene bonded with octyl-imidazolium ionic liquids (IMP6A-C4) as a stationary phase for gas chromatographic (GC) separations was designed, synthesized, and characterized. The IMP6A-C4 capillary column, prepared by the static coating method, had medium polarity (133) and relatively high column efficiency of 4982 plates/m determined by n-dodecane at 120 ℃. As demonstrated, through the separation of the mixture of 17 aliphatic analytes and the mixture of 20 analytes with different polarities, the IMP6A-C4 column exhibited privileged retention and high resolving capacity for H-bonded and aromatic analytes, suggesting advantages over the P6A-C4 column and common polysiloxane HP-5 and HP-35 columns. Strikingly, it implemented high resolutions with good peak shapes for isomer mixtures of phenols, anilines, and benzaldehydes. These findings demonstrated that the excellent resolving performance of the IMP6A-C4 column can be attributed to the comprehensive interactions of its rigid 3D aromatic cavities and polar imidazolium ionic liquids, including π-π, ion-π, H-bonding, dipole–dipole interactions. On the other hand, the IMP6A-C4 capillary column exhibited good repeatability and reproducibility with the RSD% values in the range of 0.01–0.03% for run-to-run, 0.09–0.32% for day-to-day, and 2.72–5.23% for column-to-column. The satisfactory separation performance reveals the promising prospects of the IMP6A-C4 stationary phase in separation science.

DEVELOPMENT AND VALIDATION OF THE HS-GC-FID METHOD FOR THE QUANTIFICATION OF RESIDUAL SOLVENTS IN DESLORATADINE

Testing for residual solvents is a crucial component of both reference material certification and pharmaceutical quality control. Developing and validating a head space-gas chromatography method for measuring residual solvents in desloratadine in pharmaceutical dosage forms was the aim of the current investigation. To create desloratadine, an active ingredient in pharmaceuticals, the pharmaceutical industry commonly uses organic solvents such as methanol, diethyl ether, dichloromethane, and tetrahydrofuran. A novel technique for measuring residual solvents in desloratadine was created using a flame ionization detector and headspace gas chromatography. HP1 Column (30m×0.53mm, 1.8µm), intake port maintained at 250°C, detector temperature 260°C, oven temperature 190°C, and injection volume 1µl with 1:50 split ratio utilizing nitrogen as a carrier gas at a flow rate of 1ml/min were the optimum chromatographic conditions. Using criteria from the International Conference on Harmonization, the method's linearity, range, detection limit, quantitation limit, accuracy, precision, specificity, system appropriateness, and robustness were all validated. It was determined that the idea was appropriate for determining four distinct residual solvents. The approach is particular, linear, exact, accurate, and sensitive, according to validation data, where recoveries varied from 90 to 110 percent. This thoroughly tested technique has been used to identify any remaining solvents in actual desloratadine bulk samples.

CORIANDER (Coriandrum Sativum L.) ESSENTIAL OIL CHANGES LEVELS DURING THE SPRING SEASON

Essential oils have been used for thousands of years for medicinal, health, and food purposes. Coriander (Coriandrum sativum L.), which belongs to the Mediterranean countries, is an herbaceous plant and a rich source of vitamins and minerals. There was a concentration on coriander's medical and nutritional aspects. Corianders were harvested for three consecutive months. Each time, they were transferred to the laboratory. Their essential oils were measured using a GC-MS (Hewlett Packard - US). Essential oils were identified by calculating specific indices and at programmed temperature conditions for (C6 - C26) oils of an HP-5 column under identical operating conditions. Essential oils evaluation was done in three replicates at each harvesting time, and the difference in the essential oil content showed the effect of harvesting stages on them. A total of 45 essential oils were measured in three harvesting stages. Linalool (3.46, 7.05, and -6.27% from the first to the third harvest, respectively) was identified as the main component in coriander oil. In the first harvest, the mass under study contained more than 20% Germacrene, which was reduced to below 2% in subsequent harvests. Also, Decanal, Cyclodecane, 2-docecen-1-ol, Tetradecanal, Neophetadiene, Oleic acid, and phytol had a significant percentage in all three harvests. Coriander samples had significantly higher amounts of essential oils as green leafy vegetables. On the other hand, scientists can achieve medical extract of coriander. It is concluded that coriander is a valuable sample to use in both the medical and food industries.

Lindane bioremediation by Paenibacillus dendritiformis SJPS-4, its metabolic pathway analysis and functional gene annotation

Lindane, hexachlorohexane is an organic persistent pesticide reaches the water bodies via agricultural waste water runoff or rainfall. The present study shows the lindane bioremediation potential of Paenibacillus dendritiformis SJPS-4 and its degradation potential which was evaluated using gas chromatography 7890A equipped with HP-5 column and electron capture detector (μECD). Further, the effect of whole cell immobilization resulted the lindane degradation of 80.72% in mineral salt medium (MSM-L) with significant degradation after immobilization of bacterial cells in alginate beads and agar cubes. The functional gene annotation using KEGG-KASS tools revealed the metabolic pathway for lindane degradation involving lin genes (lin A, lin E, lin B, lin X, lin C, lin D) acting on subsequent compound at each step including the subsequent metabolites in the pathway were utilized. This study gives the new insights on the potential of naturally occurring bacteria Paenibacillus dendritiformis SJPS-4 towards its role in decontaminating such environments.

Selective Separation of Polar Unsaturated Organics Using a Water Stationary Phase in Gas Chromatography

A water stationary phase is explored as a novel means of selectively separating unsaturated analytes in gas chromatography. Several unsaturated/saturated analyte pairs consisting mainly of carboxylic acids and alcohols were examined using both a 30-m conventional non-polar HP-5 column and an 11-m water phase column. For most investigated on the HP-5 column, analytes often eluted very close to each other (~ 6–12 s apart) with poor resolution. By comparison, the shorter water phase column well separated each of the analogue pairs by about 3–8 min or more. As well on the water phase, analytes with a triple bond were much more retained than those with two double bonds, which in turn were much more retained than those with one double bond. Conversely, on the HP-5 column these were poorly separated if at all. Additionally, cis/trans isomers were baseline resolved on the water phase but co-eluted on a 30-m conventional polar Carbowax column. Similarly, positional isomers varying the location of the double bond were found to separate with a selectivity value near 1.1 on the Carbowax column, whereas on the water phase column they yielded a value of 1.3 and eluted in the reverse order. Addition of various metal ion salts to the water phase was explored. While Ca2+ ion produced modest increases in selectivity, the addition of Ag+ ion was most influential and further increased the original water phase selectivity by a factor of 2.3. The mechanistic implications of OH–-pi bonding in the water phase was discussed as a potential origin for the selectivity observed. The method was applied to gasoline, essential oil, and food stuff analysis. Results indicate that this method could be a very useful means of selectively separating such unsaturated analytes.Graphical abstract

Biologically active components of lipid complex in pressed wine yeast

In this work we made an attempt to determine, quantitatively and qualitatively, the isoprenoid including sterol) the composition of the lipid complex of pressed wine yeast from a grape must fermentation. The sterol composition of the lipid complex we obtained was studied using a method for determination of unsaponifiable substances in vegetable oils. Isoprenoid, including sterols, were determined by gas-liquid chromatography. The chromatograph used was an Agilent Technology 6890 with a mass-spectrometry detector and had a HP-1 column. The carrier gas (helium) flow rate was 1 ml/min. The chromatography was effected at a temperature range of 50-300°C. The revealed unsaponifiable fraction of the yeast lipid complex contained diterpenoid and triterpenoid alcohols and sterols. The sterols were campesterol, β-stigmasterol, obtusifoliol, γ-sitosterol, lanosterol, cycloartenol and α-sitosterol), hydrocarbons, α-tocopherol and γ-tocopherol, the total sterols accounting for 22.3 %. These findings clearly indicate the need to investigate, in more detail, the pharmacological and antioxidant effects of the wine yeast lipid complex from a grape must fermentation.

Determination of the butanone in urine by gas chromatography with precolumn derivation

Objective: To establish a method for determination of the butanone in urine by gas chromatography (GC) with pre-column derivation. Methods: For detecting of butanone in urine, potassium iodide and potassium dichromate were added into urine under acidic condition, sample derivatization was undertaken in 50 ℃ water bath for 60 min and the iodine butanone was extracted with n-hexane. After the sodium thiosulfate solution was used to remove excess iodine, urine samples were centrifuged at 10000 r/min for 5 min, then the supernatant was analyzed using temperature rising programming with the Agilent Hp-5 column (30 m×0.32 mm, 0.25 μm) and electron capture detector (ECD) as the detector. The detector temperature was 300 ℃, the inlet temperature was 200 ℃, and the carrier gas was nitrogen. Results: For detecting of butanone in urine, potassium iodide and potassium dichromate were added for derivatization under the acidic condition. After extraction and centrifugation, the supernatant directly put through column and detected by ECD. In present study, the sample pretreatment condition was optimized, the relative standard deviations of intra-day and inner-day, the spiked samples and its recovery were evaluated for analyzing the accuracy of the proposed method. Conclusion: This method has proved to be simple, efficient and highly sensitivity, it can be utilized for butanone detection in occupational population.

Albizia lebbeck and Albizia zygia volatile oils exhibit anti-nociceptive and anti-inflammatory properties in pain models

Ethnopharmacological relevanceAlbizia lebbeck and Albizia zygia are used in Nigeria, South Africa and other countries for the treatment of flu, fever, pain, epilepsy, and inflammation.Aim of the Study: Application of plant essence for treating ailments is common among local communities. This research was designed to characterize the volatile compounds and evaluate the toxicity, anti-inflammatory and anti-nociceptive properties of this plant species. Materials and methodsThe volatile oils were analysed comprehensively utilizing gas chromatography-flame ionization detector (GC-FID) and gas chromatography coupled with mass spectrometry (GC/MS) using the HP-5 column. The toxicity was evaluated using the toxicity assay. The anti-nociceptive and anti-inflammatory assays were analysed by a hot plate, Formalin, and carrageenan-induced edema assays, respectively. ResultsThe essential oils were obtained in a yield of 0.1% (v/w) calculated on a dry weight basis for both oils. The main compounds of A. lebbeck were 2-pentylfuran (16.4%), (E)-geranyl acetone (15.46%), (E)-α-ionone (15.45%) and 3-Octanone (11.61%), while the oil of A. zygia is mainly hexahydrofarnesyl acetone (33.14%), (E)-methyl isoeugenol (11.7%) and 2-methyl tetradecane (6.64%). The volatile oils are non-toxic to about 5000 mg/kg dose. Albizia zygia significantly (P < 0.001) suppressed the nociceptive afferent fibres in a non-dose dependent manner in comparison to A. lebbeck in the hot plate model. Both oils inhibited nociceptive mediators at both phases of the formalin-induced assay, with a maximum inhibition (100%) at the inflammatory stage. The volatile oils inhibited the Carrageenan-induced inflammation at all phases ranging from P < 0.05 to P < 0.001. The probable pro-inflammatory inhibitory mechanism might be the suppression of some pain biomarkers such as histamine, serotonin, bradykinin, and the Interleukins (ILs) induced by the edema. Volatile constituents such as ionones, eugenol derivatives and other compounds cause the anti-nociceptive and anti-inflammatory activities reported. ConclusionThis is the first report of the volatile oils and bioassays of Albizia zygia, while the study also confirms previous studies of A. lebbeck. Generally, the findings further prove the use of the plants as pain ameliorating agents.

Capillary gas chromatographic determination of isoniazid in pharmaceutical preparations and blood precolumn derivazation with trifluoroacetylacetone

Antituberculosis drug isoniazid (INH) and hydrazine (HZ) have been determined by capillary column gas chromatography after precolumn derivatization with trifluoroacetylacetone (FAA). Phenylhydrazine (PHZ) when present together with INH and HZ also separated completely from the column HP-5 (30 mm × 0.32 mm I.D) connected with flame ionization detection (FID), and thus was used as an internal standard. The linear calibration ranges for INH and HZ were determined to be 2.5-25 μg/mL and 2.5-21.2 μg/mL respectively, with detection limit (S/N = 3) corresponding 62.5 pg reaching to the detector. The method was applied for the determination of INH and HZ from pharmaceutical preparations. The method was also used for determination of INH from blood of tuberculosis patient. The amount of INH found in the blood serum of tuberculosis patients on chemotherapy with INH based drugs was within 0.82-4.8 μg/mL with relative standard deviation (RSD) of 2-5.8%. The recovery percentage of INH from blood samples was found 98% with RSD 2.5%.

Volatile Composition, Toxicity, Analgesic, and Anti-Inflammatory Activities of Mucuna pruriens

The volatile constituents, toxicity, antinociception, and anti-inflammatory activities of the essential oil obtained from the leaf of Mucuna pruriens utilis collected from Nigeria are reported. The essential oil was analyzed comprehensively utilizing gas chromatography (GC)-flame ionization detector and GC coupled with mass spectrometry (MS) using the HP-5 column. The antinociceptive and anti-inflammatory assays were analyzed by a hot plate, formalin, and carrageenan-induced edema assays, respectively. The essential oil was obtained in a yield of 0.2% (v/w) calculated on a dry weight basis. A total of 36 compounds representing 94.8% of the oil contents were identified. The oil contained a high content of ( E)-2-hexenal (19.0%), linalool (8.9%), 1-hexanol (6.6%), and trans-dehydroxylinalool oxide (5.2%). The analgesic property of the essential oil was slightly significant ( P &lt; 0.5) only at the third hour for the 400 mg/kg while other doses are less active. The rate of inhibition was moderate (24.1%-54%) during the analgesic phase of the formalin assay. The rate of inhibition at the anti-inflammatory phases of both formalin and carrageenan were significantly high (100%) and P &lt; 0.001 for all the doses during the reaction duration. The potential proinflammatory mechanism might be due to effects on several proinflammatory mediators, including, histamine, serotonin, and bradykinin, and the ability of the essential oils to act as centrally mediated opioid analgesic. Mucuna pruriens essential oils displayed a high anti-inflammation potential and can be used as a potential centrally mediated opioid antagonist against analgesia.

Employing predicted response factors and a validated chromatographic method for the relative quantitation of holy basil essential oils

ABSTRACT This work reports on fourteen holy basil (Ocimum tenuiflorum L., O. gratissimum L.) essential oil profiles, and a reliable method for quantitation of essential oil constituents via a combination of external and internal standardization approaches using predicted relative response factors (RRFs). Results demonstrate one variety was composed primarily of methyl eugenol (~65 %), and another of eugenol (67%). Multiple varieties contained moderate eugenol (~37-45%) and β-caryophyllene (~23-37%) levels, while others possessed equally fair quantities of eugenol, eucalyptol, estragole, and β-bisabolene. The developed method showed good precision and repeatability with a relative standard deviation (RSD) < 4% for all tests. The reliability of predicted RRFs was evaluated with a difference of 0.96 ± 0.25 to 11.21 ± 1.34% between the two quantitation methods. High concentration compounds showed greater differences between calculated and predicted values. Finally, an HP-5 column provided excellent resolution, except for essential oils containing methyl eugenol and β-caryophyllene.

VALIDATION AND ANALYSIS OF DIALLYL DISULFIDE AND DIALLYL TRISULFIDE IN GARLIC (ALLIUM SATIVUM L.) USING GAS CHROMATOGRAPHY

Objective: The purpose of this research was to optimize and validate a method for measuring the levels of diallyl disulfide (DADS) and diallyl trisulfide(DATS) in garlic and single clove garlic.Methods: The analysis was performed using gas chromatography (GC) equipped with an HP-1 column and a flame ionization detector. The initialcolumn temperature was set at 140°C and increased at 1°C/min to 180°C. The injector and detector temperatures were set to 200°C, the carrier gasflow rate was 0.80 mL/min, and the injection volume was 1.0 μL. The optimized conditions of analysis were then validated which included selectivity,linearity, accuracy, precision, limit of detection (LOD), and limit of quantification (LOQ).Results: Using the validated assay and a concentration range of 0.5–20 μg/mL, the coefficient of correlation (r) for DADS was 0.9999 and the LODand LOQ for DADS were 0.3063 μg/mL and 1.0210 μg/mL, respectively. Using the validated assay and a concentration range of 0.5–20 μg/mL, thecoefficient of correlation for DATS was 0.9999 and the LOD and LOQ for DATS were 0.1986 μg/mL and 0.6621 μg/mL, respectively. The percentage ofrecovery was in the range of 98.05–101.76% and coefficient of variation ≤ 2%.Conclusion: This GC method accurately measures the levels of DADS and DATS in garlic.

Chemical Composition and Larvicidal Activity of Essential Oil from the Rhizomes of Amomum rubidum Growing in Vietnam

This work reports the chemical constituents and larvicidal activity of essential oil from Amomum rubidum Lamxay & N. S. Lý. The essential oil was extracted from the air-dried rhizome in an all-glass Clevenger-type apparatus and characterized by gas chromatography (GC-FID) and gas chromatography/mass spectrometry (GC/MS) on HP-5 column. The larvicidal property was evaluated against the fourth-instar larvae of Aedes aegypti according to the protocols of the World Health Organization. A. rubidum essential oil was characterized by high amounts of β-phellandrene (16.1 %), limonene (14.4 %), and δ-3-carene (13.9 %). The oil displayed larvicidal activity against Ae. aegypti with minimum lethal concentration, LC50 values of 22.85 and 22.62 μg/mL respectively at 24 h and 48 h, while the LC50 values of 31.44 μg/mL and 31.03 μg/mL were obtained respectively at 24 h and 48 h. The chemical constituents and larvicidal actions of A. rubidum rhizome essential oils are being reported for the first time.

Chemical Constituents of Essential Oil from the Leaves of Phyllanthus muellerianus (O. Kuntze) Exell

The chemical compounds identified in the essential oil hydrodisitlled from the leaves of Phyllanthus muellerianus (O. Kuntze) Exell (family Euphorbiaceae) are being reported in this study. The essential oil was analysed comprehensively by means of gas chromatography-flame ionization detector (GC-FID) and gas chromatography coupled with mass spectrometry (GC/MS) using HP-5 column. The light yellow essential oil was obtained in a 0.12 % (v/w), calculated on a dry weight basis. The main classes of compounds present in the leaf oil were sesquiterpene hydrocarbons (75.1 %) and oxygenated sesquiterpenes (20.1 %). The major constituents of the leaf oil were mainly sesquiterpene hydrocarbon compounds represented by β-caryophyllene (41.9 %), germacrene D (9.6 %) and α-humulene (7.4 %), as well as oxygenated sesquiterpene compounds comprising caryophyllene oxide (9.1 %) and (E)-nerolidol (6.0 %).

Chlorobenzene. Determination in workplace air

Chlorobenzene is a colorless, flammable liquid that has an almond-like odor. It is used in industry as a solvent: resins, paints and fats, raw material for the production of plastics, as well as for the production of phenol, aniline and nitrobenzene. Occupational exposure to chlorobenzene vapors can occur through inhalation, absorption through the skin or ingestion. Harmful if inhaled, causes skin irritation. Long-term exposure affects the central nervous system. The aim of this study was an amendment to the PN-Z-04022- 03:2001 withdrawn from the Polish set of standards, and validate method for determination concentrations of chlorobenzene in the workplace air in the range from 1/10 to 2 MAC values, in accordance with the requirements of the standard PN-EN 482. The study was performed using a gas chromatograph (GC) with a flame ionization detector (FID) equipped with a capillary column HP-5 (30 m x 0.32 mm, 0.25 μm). This method is based on the adsorption of chlorobenzene vapors on activated charcoal, desorption with carbon disulfide, and analyzed by GC-FID. Application of HP-5 column allows selective determination of chlorobenzene in a presence of carbon disulfide, aniline, phenol and nitrobenzene. The measurement range was 2.3 ÷ 46 mg/m3 for a 15 l air sample. Limit of detection: 6.75 ng/ml and limit of quantification: 20.25 ng/ml. Analytical method described in this paper enables selective determination of chlorobenzene in workplace atmosphere in presence of other solvents at concentrations from 2.3 mg/m3 (1/10 MAC value). The method is characterized by good precision and accuracy and meets the criteria for the performance of procedures for the measurement of chemical agents, listed in EN 482. The method may be used for the assessment of occupational exposure to chlorobenzene and the associated risk to workers’ health. The developed method of determining chlorobenzene has been recorded as an analytical procedure (see Appendix). This article discusses the problems of occupational safety and health, which are covered by health sciences and environmental engineering.

VALIDATION GAS CHROMATOGRAPHY-FID METHOD FOR ANALYSIS OF ETHANOL CONTENT IN VINEGAR

Production process of vinegar could be synthesized by chemical or microbiological. In Islam, vinegar must not be consumed if contains ethanol ≥ 1%, because it is categorized into khamr. The maximum concentration of vinegar fermentation is 1,0 %. This research was to analyze the alcohol compund that consist in vinegar. The validation method that used in this study are: selectivity, linearity, range, precision, accuracy, LOD and LOQ. The analysis instrument was gas chromatography Agilent 6890 Series GC System, with a Flame Ionization Detector (FID) and a column HP-5 (5% Phenyl 95% Methyl Siloxane), and optimal conditions were obtained by using temperature of inlet and detector of 250°C whilst the temperature of oven programed initially at 40°C, hold for 5 minutes, and raised to 5°C/min to 200°C. were used in this study. For split ratio was achieved at 50:1 and the injection volume was 1.0µl. The methods were proven selective and demonstrated linearity, precision and accuracy with r = 0.9995; 5,63% and 101,25%, respectively. On the other hand, the methods were proven that the sample contains alcohol. Finally, the result of quantitative ethanol contents analysis in vinegar from Saudi Arabia is 2,28.10-2 % v/v; and vinegar brand “x” from market in Surabaya is 1,17.10-2 v/v.

ACCELERATED STABILITY TESTING OF ANTI-AGING CREAM: FORMATION OF MYRISTIC ACID AND STEARIC ACID AS DEGRADATION PRODUCTS

Objective: This study aimed to determine the stability of anti-aging cream using the accelerated stability test and calculating the levels of myristicacid and stearic acid as degradation products.Methods: Optimum conditions and validation methods for the mixture of myristic acid and stearic acid were determined to obtain a valid method fordetermining the levels of degradation products in anti-aging cream. Derivatization was performed with the Lepage esterification method, which usesmethanol-toluene 4:1 (v/v) and acetyl chloride catalysts. The analysis was performed using gas chromatography (GC) Shimadzu GC-17A system withan HP-1 column and flame ionization detection.Results: The column temperature was 120°C, with an increase of 10°C/min (up to 160°C) followed by an increase of 3°C/min (up to 220°C;maintained for 5 min) and an increase of 10°C/min (up to 260°C; maintained for 5 min). The injector and detector temperatures were 260°C and280°C, respectively, with a flow rate of 1 mL/min. The retention times of myristic acid and stearic acid were 16.655 min and 28.169 min, respectively,with tailing factor values of 0.734 and 0.943, respectively. Validation results fulfilled our acceptance criteria, which obtained linearity for myristicacid at y=9.6483+190.78x, with a correlation coefficient (r) value of 0.9997, limit of detection (LOD)=0.0013 parts per million (ppm), and limitof quantification (LOQ)=0.0042 ppm. The linearity for stearic acid was determined at y=17.163+106.22x, with a correlation coefficient (r) valueof 0.9998, LOD=0.0016 ppm, and LOQ=0.0053 ppm. Results of the anti-aging cream stability test indicated that the average remaining levels ofisopropyl myristate from 0 to 3 months were 99.6283%, 99.1995%, 98.2571%, and 97.1511%, respectively. The average remaining levels of glycerylmonostearate were 99.6791%, 98.2881%, 96.2247%, and 93.7195% from 0 to 3 months, respectively.Conclusion: The expiration date of the anti-aging cream product was then calculated using zero-order kinetics and determined to be 10 months and9 days.

Chemical composition, anti-nociceptive and anti-inflammatory activities of essential oil of Bougainvillea glabra

Ethnopharmacological relevanceBougainvillea glabra is widely used in Nigeria for the treatment of inflammatory-related conditions, and as remedy for pain ailments. Aim of the studyConsidering the lack of scientific studies focused on chemical constituents and pharmacological activity of B. glabra essential oil, this work was designed to characterize the volatile compounds and evaluate the anti-inflammatory and anti-nociceptive properties ascribed to this plant species. Materials and methodsThe essential oil was extracted from the leaf of B. glabra by hydrodistillation in an all glass Clevenger-type apparatus and characterized by gas chromatography (GC-FID) and gas chromatography-mass spectrometry (GC-MS) on HP-5 column. The anti-inflammatory property of the essential was established by measurement of carrageenan induced rat paw edema while the anti-nociceptive activity was determined by hot plate test, according to established procedures. ResultsThe essential oil was obtained in a yield of 0.08% (v/w) calculated on dry weight basis. A total of 11 compounds representing 96.2% of the oil contents were identified by GC/MS. The main constituents of the essential oil were (E)-nerolidol (31.4%), (E)-β-ionone (10.3%) and linalool (10.1%). The anti-nociceptive property of the essential oil was statistically significant p < 0.001 at all doses of when compared to the control while exhibiting an activity in tandem with the standard drug. For the 1st and 2nd h, at doses of 100 and 200 mg/kg, the anti-inflammatory activity was statistically very significant (p < 0.001), while at 3rd h the activity declined (p < 0.01) at a dose of 200 mg. The activity was non-significant at the 4th h experimental duration. ConclusionsThis is first report on the chemical constituents and biological activity of essential oil of B. glabra from Nigeria. Overall, the results herein presented sustain and strengthen the anti-nociceptive and anti-inflammatory properties traditionally ascribed to B. glabra.

Enantioselective degradation of the chiral alpha-cypermethrin and detection of its metabolites in five plants.

Alpha-cypermethrin (α-cypermethrin), an important chiral pyrethroid insecticide, is frequently detected in human samples. Because of the possible human health risks caused by α-cypermethrin, we studied dynamics, residues, and metabolism of α-cypermethrin in five common vegetables (tomato, cucumber, rape, cabbage, and pepper) on enantiomeric levels after foliar spray. α-Cypermethrin was qualified by a HP-5 column and its enantiomers could be separated by gas chromatograph (GC) using a BGB-172 chiral column. The results of degradation showed that α-cypermethrin dissipated rapidly in vegetables with half-lives being only 2.85-8.88days. Stereoselective degradation was observed on pepper and cucumber while the two metabolites (cis-DCCA and 3-PBA) of α-cypermethrin were not detected during its dissipation in all plants. This is the first evidence of enantioselective degradation of α-cypermethrin in the five common vegetables and the results should be considered in future environmental risk and food safety evaluations.

APPLICATION OF MATHEMATICAL PLANNING OF THE EXPERIMENT IN THE CHOOSING THE OPTIMUM CONDITIONS OF THE VAPOR-PHASE GAS-CHROMATOGRAPHIC DETERMINATION OF FORMALDEHYDE IN THE URINE

Introduction. There was substantiated a method for the determination of formaldehyde by vapor-phase gas chromatography by the use of derivatizing reagent o-(2,3,4,5,6-pentafluorbenzyl)hydroxylamine. Material and methods. Formaldehyde in urine was derivatized to o-pentafluorobenzyloxime and recovered to the vapor phase by heating the urine sample with o-(2,3,4,5,6-pentafluorbenzyl)hydroxylamine in a sealed vial. Gas-chromatographic analysis of the vapor-air phase was performed in a mode of the temperature gradient on a capillary column HP-5 with a flame ionization detector. Identification of the analyte in the form of the derivative-o- pentafluorobenzyloxime of formaldehyde was carried out according to the absolute retention time, which was established by comparing the chromatograms of model formaldehyde mixtures in the urine of different concentrations. Results. The optimal conditions for gas extraction are selected using mathematical experimental planning. The most important factors of gas extraction in the vapor-phase analysis are the temperature and time of the establishment of the interphase equilibrium with heating. From the experimentally obtained curves of the analytical signal on the temperature and the heating time, the zero level and the interval of variation of these factors are chosen. A matrix for planning a 2-factor experiment was constructed. The coefficients of the mathematical model are determined. There was carried out statistical processing of the experimental data, which was reduced to the estimation of the reproducibility of the optimization parameter and to the evaluation of the significance of the coefficient of the mathematical model. The adequacy of the mathematical model was evaluated, its interpretation was carried out. Discussion. The peak area of the analyte increases with the elevating the temperature and heating time, due to an increase in the analyte concentration in the vapor phase. Moreover, the heating time makes a greater contribution to the formation of the analytical signal than the temperature. The step of motion along the gradient was calculated and the experiments of steep ascent were carried out. Conclusion. According to the results of the steep ascent experiments, the optimal conditions for the gas extraction of formaldehyde in the form of a derivative were chosen.