A simplified method for determining 1-aminocyclopropane-1-carboxylic acid (ACC) in plant tissues using a mass selective detector

1989 ◽  
Vol 8 (4) ◽  
pp. 297-307 ◽  
Author(s):  
K. C. Hall ◽  
D. M. E. Pearce ◽  
M. B. Jackson
Keyword(s):  
Carboxylic Acid ◽  
Plant Tissues ◽  
Mass Selective Detector ◽  
Selective Detector ◽  
Simplified Method

scholarly journals Application of chromato-mass-spectrometric methods of determination of exposure markers in biomonitoring researches in workers of productions of polyvinyl chloride and aluminum

2020 ◽  
Vol 99 (10) ◽  
pp. 1159-1164
Author(s):  
Salim F. Shayakhmetov ◽  
Olga M. Zhurba ◽  
Anton N. Alekseenko ◽  
Alexey V. Merinov
Keyword(s):  
Polyvinyl Chloride ◽  
Mass Spectrometric ◽  
Aluminum Production ◽  
Control Groups ◽  
Biological Media ◽  
Mass Selective Detector ◽  
Selective Detector ◽  
Highly Sensitive ◽  
Polycyclic Aromatic

Introduction. The presence of highly toxic polycyclic aromatic hydrocarbons (PAHs) in the production of aluminum and organochlorine compounds (OCC) in the production of polyvinyl chloride (PVC) poses a serious threat to the health of workers, necessitates biological monitoring of toxicants and their metabolites in biological media to assess health risks on basis of modern methods chemical analysis. Material and methods. Biomonitoring studies of the content of marker metabolite OCC - thiodiacetic acid (TDAA) in urine were performed in 65 workers of PVC production and PAHs metabolite - 1-hydroxypyrene (1-OHPyr) in 144 workers of the aluminum smelter using developed own methods of gas-chromato-mass-spectrometric (GC-MS) analysis. Sample analysis was performed on an Agilent 7890A gas chromatograph with an Agilent 5979 mass selective detector. Results. Methodological methods and parameters of GC-MS measurement of TDAA and 1-OHPyr in urine, which provided high selectivity and sensitivity of the analysis of samples, were examined and considered. Reliable differences in the levels of marker metabolites among the groups of main and auxiliary occupations and persons in the control groups, their dependence on the degree of exposure to PAHs, and OCC were established. The highest concentrations of TDAA in urine were observed in unit operators of PVC workshop and 1-OHPyr - in anode workers of aluminum production. Discussion. The revealed reliable intergroup and interindividual differences in the contents of TDAA and 1-OHPyr in the urine of workers indicate the reliability and informativeness of the results of the analysis of biological media. The results are consistent with data from foreign studies, confirm the occupational - production nature of the exposure of toxicants among workers in the main professions of enterprises. Conclusion. The results of approbation of highly sensitive and selective methods for the determination of TDAA and 1-OHPyr in urine samples developed on the base of GC-MS method demonstrate the possibility of their use in biomonitoring studies of workers of productions and the population to adequately assess the exposure of highly toxic PAHs and OCC.

scholarly journals Determina tion of diacetyl and 2,3-pentanedione in beer by gc/ms using solid-phase extraction columns

2002 ◽  
pp. 45-54 ◽  
Author(s):  
Jelena Pejin ◽  
Olgica Grujic ◽  
Nikola Marjanovic ◽  
Djura Vujic ◽  
Suncica Kocic-Tanackov
Keyword(s):  
Gas Chromatography ◽  
Solid Phase Extraction ◽  
Simultaneous Determination ◽  
Solid Phase ◽  
Phase Extraction ◽  
Mass Selective Detector ◽  
Selective Detector

A new GC/MS method for the determination of diacetyl and 2,3-pentanedione was investigated. Diacetyl and 2,3-pentanedione were derivatized with 1,2-diaminobenzene to form 2,3-dimetylquinoxaline and 2-ethyl-3-methylquinoxaline. respectively. The amounts of formed 2.3-dimetylqu:inoxaline and 2-ethyl-3,.methylquinoxaline were proportional to the concentrations of diacetyl and 2,3-penianedione present in the sample. 2,3-Dimetylquinoxaline and 2-ethyl-3-methylquinoxaline were extracted by solid-phase extraction (SPE) columns and determined by gas chromatography using a mass selective detector. This method was applied for the determination of diacetyl and 2,3-pentanedione concentrations in beer. Extraction by SPE columns proved to be very simple and reliable. The method can be used for simultaneous determination of diacetyl and 2,3-pentanedione concentrations in beer in a great number of beer samples.

scholarly journals Excretion of ropivacaine with breast milk during prolonged analgesia of a postoperative wound

2021 ◽  
Vol 14 (3) ◽  
pp. 149-155
Author(s):  
А. А. Vinokurova ◽  
M. A. Hofenberg ◽  
V. A. Bagin ◽  
S. G. Dubrovin ◽  
V. A. Rudnov
Keyword(s):  
Breast Milk ◽  
Continuous Infusion ◽  
Spinal Anesthesia ◽  
Infectious Complications ◽  
Loading Dose ◽  
Wound Infiltration ◽  
Mass Selective Detector ◽  
Number Of Patients ◽  
Selective Detector ◽  
The Mean

The aimof our study was to evaluate the safety of ropivacaine given to lactating patients as a continuous infusion according to the selected local continuous wound infiltration (CWI) protocol after cesarean section (CS). Materials and methods.Elective CSs were performed under spinal anesthesia with bupivacaine 5% -2 ml at the L2L3 level. At the end of the operation, a 22 cm multiperforated catheter was placed in the surgical wound under the aponeurosis. 3 hours after spinal anesthesia a loading dose 8 ml of 0.2% ropivacaine was administered and followed by continuous infusion at rate 4 mL/h for 48 hours. Aside from CWI, all patients received systemic anesthesia: acetaminophen 4000 mg per os, ketorolac 90 mg IV and rescue opioid tramadol up to 400 mg (as-needed) daily. Breast milk (colostrum) samples were collected after 24 and 48 hours after a loading dose and were analyzed by gas chromatography with a mass selective detector for total ropivacaine concentrations. Results.The number of patients included in the study was 8. During the study neither cases of the onset of symptoms associated with systemic toxicity of ropivacaine, nor allergic and infectious complications, were observed. The mean +- SD Cmax total colostrum ropivacaine concentration was 0.005 0.002 (0.002 0.007) g / ml. Conclusion.In this limited sample, increasing the concentration or/and infusion rate seems to be a safe (for both mother and newborn) alternative or adjunct to standard systemic analgesia after CS in order to provide proper postoperative pain control.

scholarly journals Optimal Extraction of Ocimum basilicum Essential Oil by Association of Ultrasound and Hydrodistillation and Its Potential as a Biopesticide Against a Major Stored Grains Pest

Molecules ◽  
2020 ◽  
Vol 25 (12) ◽  
pp. 2781 ◽  
Author(s):  
Eridiane da Silva Moura ◽  
Lêda Rita D’Antonino Faroni ◽  
Fernanda Fernandes Heleno ◽  
Alessandra Aparecida Zinato Rodrigues ◽  
Lucas Henrique Figueiredo Prates ◽  
...  
Keyword(s):  
Biological Activity ◽  
Essential Oil ◽  
Insect Pests ◽  
Extraction Process ◽  
Ocimum Basilicum ◽  
Gas Chromatograph ◽  
Drying Temperature ◽  
Mass Selective Detector ◽  
Potential Control ◽  
Selective Detector

The essential oil of basil (Ocimum basilicum) has significant biological activity against insect pests and can be extracted through various techniques. This work aimed to optimize and validate the extraction process of the essential oil of O. basilicum submitted to different drying temperatures of the leaves and extracted by the combination of a Clevenger method and ultrasound. The biological activity of the extracted oil under different conditions was evaluated for potential control of Sitophilus zeamais. The extraction method was optimized according to the sonication time by ultrasound (0, 8, 19, 31 and 38 min) and hydrodistillation (20, 30, 45, 60 and 70 min) and drying temperature (20, 30, 45, 60 and 70 °C). The bioactivity of the essential oil was assessed against adults of S. zeamais and the effects of each variable and its interactions on the mortality of the insects were evaluated. The best yield of essential oil was obtained with the longest sonication and hydrodistillation times and the lowest drying temperature of leaves. Higher toxicity of the essential oil against S. zeamais was obtained by the use of ultrasound for its extraction. The identification and the relative percentage of the compounds of the essential oil were performed with a gas chromatograph coupled to a mass selective detector. The performance of the method was assessed by studying selectivity, linearity, limits of detection (LOD) and quantification (LOQ), precision and accuracy. The LOD and LOQ values for linalool were 2.19 and 6.62 µg mL−1 and for estragole 2.001 and 6.063 µg mL−1, respectively. The coefficients of determination (R2) were >0.99. The average recoveries ranged between 71 and 106%, with coefficient of variation ≤6.4%.

Studies in the respiratory and carbohydrate metabolism of plant tissues XIII. The influence of oxygen at high pressures in increasing and decreasing the respiration of potatoes at 15 °C

1963 ◽  
Vol 158 (971) ◽  
pp. 143-155 ◽  
Keyword(s):  
Carboxylic Acid ◽  
Carbohydrate Metabolism ◽  
High Pressures ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Total Carbon ◽  
Plant Tissues ◽  
Sugar Phosphate ◽  
Oxygen Inhibition ◽  
Acid Cycle

The CO 2 output of potatoes held at 15 °C in oxygen at a pressure of either 2 or 3 atm was first decreased, then increased and finally again decreased. The increase of CO 2 output was much larger than in carrots (Barker 1961); in oxygen at a pressure of 2 atm the rate of CO 2 output of potatoes was increased 4.6 fold; taking into account the accumulation of citrate, the ‘total carbon traffic’ was increased 5.6 fold in oxygen. This increase was believed to occur mainly in a pathway which was not the tricarboxylic acid cycle. As in potatoes held at 1 °C in an atmosphere of oxygen (Barker & Mapson 1955), citrate accumulated and α -ketoglutarate decreased in potatoes, held at 15 °C in oxygen at pressures of 2 or 3 atm; these changes were accepted as demonstrating the occurrence of the tri­-carboxylic acid cycle. The final decrease of CO 2 output in oxygen appeared not to be related to the occurrence of ‘blocks’ either between citrate and α -ketoglutarate or of pyruvate or α -ketoglutarate oxidases; the inhibition might be due to a shortage of sugar phosphate substrates, caused possibly by oxygen inhibition of cytochrome- c reductase. The outburst of CO 2 , which occurred in potatoes first held in oxygen and then returned to air, could not be attributed solely to oxidation of accumulated citrate.

Determination of Twenty-one Chloroanisoles in Water and Sediment Samples

1988 ◽  
Vol 71 (4) ◽  
pp. 803-807
Author(s):  
Hing-Biu Lee
Keyword(s):  
Molecular Ions ◽  
Sediment Samples ◽  
Mass Selective Detector ◽  
Water And Sediment ◽  
Soxhlet Apparatus ◽  
Selective Detector ◽  
Electron Impact Mass ◽  
Impact Mass ◽  
Water And Sediment Samples

Abstract A simple and sensitive method for the determination of 19 chloroanisoles and 2 chloromethylanisoles was developed for water; another method was developed for sediment samples. Water samples were extracted with dichloromethane; sediments were extracted with a mixture of hexane and acetone in a Soxhlet apparatus. The extracts were concentrated on a Snyder column and then were cleaned up on an activated Florisil column. The anisoles were separated by either an OV-1 or SPB-5 capillary column and were detected by an electroncapture or a mass selective detector. Recoveries of chloroanisoles in fortified water and sediment samples generally ranged between 70 and 85%. The method detection limits were 0.02 /tg/L and 0.002 Mg/g for mono- and di-chloroanisoles in water and sediments and 0.002 jug/L and better than 0.001 jig/g for tri-, tetra-, and pentachloroanisoles in those matrixes. The electron-impact mass spectra of all chloroanisoles exhibited intense peaks for the molecular ions (M+ ), as well as (M - 43)+ and either (M - 15)+ or (M - 30)+ fragments. These masses were used as characteristic ions for quantitative and confirmation purposes.

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