Determination of Nitrilotriacetic Acid in Inland Waters by Gas Chromatography of the Trimethyl Ester

1971 ◽  
Vol 28 (7) ◽  
pp. 1043-1047 ◽  
Author(s):  
D. Murray ◽  
D. Povoledo
Keyword(s):  
Gas Chromatography ◽  
Natural Waters ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Nitrilotriacetic Acid ◽  
Inland Waters ◽  
Gas Chromatograph ◽  
Methyl Heptadecanoate ◽  
Low Concentrations

A method for the analysis of low concentrations of nitrilotriacetic acid (NTA) in natural waters was developed. The NTA was converted to the trimethyl ester and determined quantitatively by gas chromatography using methyl heptadecanoate as an internal standard. The lower limit of detection was 25 μg/liter of NTA. The identity of the ester was confirmed using a mass spectrometer–gas chromatograph combination.

Determination of volatile alcohols and acetone in serum by non-polar capillary gas chromatography after direct sample injection.

1984 ◽  
Vol 30 (10) ◽  
pp. 1672-1674 ◽  
Author(s):  
N B Smith
Keyword(s):  
Gas Chromatography ◽  
Capillary Gas Chromatography ◽  
Capillary Column ◽  
Internal Standard ◽  
Fused Silica ◽  
Gas Chromatograph ◽  
Ionization Detector ◽  
Flame Ionization ◽  
Split Ratio

Abstract In this method for detection and quantification of volatile alcohols by capillary gas chromatography, the serum sample is deproteinized, then directly injected into the gas chromatograph with 1-propanol as the internal standard. The capillary column is a 30-m bonded methylsilicone-coated, fused-silica column. With helium as the carrier gas, the injector inlet is set at a split ratio of 1/30 and the average linear velocity in the column is 25 cm/s. Injector and flame-ionization detector temperatures are 280 degrees C, oven temperature 35 degrees C. Chromatography time is less than 3 min.

Trace Analysis of Phenols in Water by Gas Chromatography

1975 ◽  
Vol 32 (2) ◽  
pp. 292-294 ◽  
Author(s):  
Derek A. J. Murray
Keyword(s):  
Gas Chromatography ◽  
Lower Limit ◽  
Water Samples ◽  
Trace Analysis ◽  
Organic Material ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Low Concentrations ◽  
Trimethylsilyl Derivatives ◽  
Derivatives Of

A method for analysis of low concentrations of phenols, cresols, and xylenols in water samples was developed. O-xylene was added to the sample as an internal standard and the sample was extracted once with chloroform to remove a portion of the total organic material present. The trimethylsilyl derivatives of the phenols were formed and analysis completed by gas chromatography. The method was rapid and required a minimum of sample manipulation. The lower limit of detection was 0.100 mg/liter for phenol, 0.025 mg/liter for cresols, and 0.050 mg/liter for xylenols.

scholarly journals Determination of Residues of Eight Synthetic Pyrethroids in Tobacco by Capillary Gas Chromatography

1994 ◽  
Vol 16 (2) ◽  
pp. 65-75
Author(s):  
BS Dattilo ◽  
S Gallo ◽  
G Lionetti
Keyword(s):  
Gas Chromatography ◽  
Film Thickness ◽  
Stationary Phase ◽  
Capillary Gas Chromatography ◽  
Capillary Column ◽  
Limit Of Detection ◽  
Synthetic Pyrethroids ◽  
Gas Chromatograph ◽  
Limit Of Determination

AbstractA method was developed for the simultaneous determination of the residues of the following eight synthetic pyrethroids and their isomers in tobacco: tetramethrin, permethrin, cyfluthrin, cypermethrin, alfamethrin, flucythrinate, fluvalinate and deltamethrin. The pesticides were extracted from ground tobacco by means of acetone:water 9:1 for 5 hours. The extract was diluted with water and partitioned into n-hexane. The organic phase was concentrated to about 1 ml and then purified by a Florisil-SPE column. The gas-chromatographic analyses were run with a gas-chromatograph Carlo Erba Series Mega HRGC 5300 equipped with a capillary column (stationary phase OV-1 - 0.10-0.15 µm film thickness, 25 m long) and a 63Ni electron-capture detector. Two different injection ports were used: split-splitless and cold split-splitless, working both with isothermal and programmed temperatures. Both the limit of detection and the limit of determination were estimated for each compound. Recoveries from fortified samples at level of 1 µgKg-1 are reported.

Determination of Linuron in Potatoes Using Capillary Column Gas Chromatography/Mass Spectrometry

1989 ◽  
Vol 72 (6) ◽  
pp. 970-974
Author(s):  
Gregory C Mattern ◽  
George M Singer ◽  
Judy Louis ◽  
Mark Robson ◽  
Joseph D Rosen
Keyword(s):  
Gas Chromatography ◽  
Ion Trap ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Gas Chromatography Mass Spectrometry ◽  
Phenylurea Herbicides ◽  
Ionization Mode ◽  
Capillary Column Gas Chromatography ◽  
Ppm Level

Abstract A convenient method for the determination of the JV-methyl,iVmethoxy- phenylurea herbicide (linuron) in potatoes has been developed. The herbicide is extracted from potatoes using a slightly modifled Luke multiresidue procedure. The extract is analyzed directly by gas chromatography with cold on-column injection, using an ion trap mass spectrometer in the chemical ionization mode as the detector. Quantitation is performed using p-bromonitrobenzene as the internal standard. The limit of detection is 0.1 ppm. Recoveries of linuron in potatoes averaged 112 ± 6% at the 0.5 ppm level, and 110 ± 2% at the 0.2 ppm level. No linuron residues were found in 25 potato samples that were analyzed by this method. Two other iV-methyl,iV-methoxyphenylurea herbicides, metobromuron and chlorbromuron, are also sufficiently stable to be determined by this method, but the N,Ndialkyl- phenylurea herbicides neburon, diuron, and monuron are too thermally unstable and degrade in the gas chromatograph.

scholarly journals Simultaneous determination of ethylene glycol and its major toxic metabolite, glycolic acid, in serum by gas chromatography

1996 ◽  
Vol 42 (2) ◽  
pp. 292-297 ◽  
Author(s):  
H H Yao ◽  
W H Porter
Keyword(s):  
Gas Chromatography ◽  
Ethylene Glycol ◽  
Simultaneous Determination ◽  
Glycolic Acid ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Toxic Metabolite ◽  
Chromatographic Procedure ◽  
Capillary Column Gas Chromatography

Abstract We developed a gas-chromatographic procedure for the simultaneous determination of ethylene glycol (EG) and its major toxic metabolite, glycolic acid (GA), suitable for clinical use in instances of EG intoxication. After serum protein precipitation with acetonitrile (containing internal standard), the supernate is treated with 2,2-dimethoxypropane (containing dimethylformamide) to remove water, and the volume is then reduced by evaporation to <100 microL of dimethylformamide (but not to dryness). After trimethylsilyl derivatization, the resulting derivatives are analyzed by capillary column gas chromatography. Only 100 microL of serum is required and the entire determination, including calibrators and controls, takes <2 h. The method gives a linear response to at least 10 g/L EG and 5 g/L GA and has a limit of detection <10 mg/L. Intraassay CV is < or = 2.8% for EG (100 and 1000 mg/L) and GA (100 and 500 mg/L); between-day CV is < or = 6.5%. The absolute recovery from serum was 91% for EG and 77-82% for GA (200 and 2000 mg/L each). Relative to calibrators prepared bovine serum albumin (70 g/L), the recovery was 99-104% for EG (100 - 5000 mg/L) and 95-105% for GA (50 - 2500 mg/L). No clinically important interference was detected for >60 exogenous or endogenous compounds and drugs.

A gas chromatography flame ionization detector method for rapid simultaneous separation and determination of six active ingredients of anticold drug

2021 ◽  
Vol 17 ◽  
Author(s):  
Fatang Yang ◽  
Xiaoyun Duan ◽  
Zhen Wang ◽  
Yuming Dong
Keyword(s):  
Gas Chromatography ◽  
Simultaneous Determination ◽  
Limit Of Detection ◽  
Flame Ionization Detector ◽  
Gas Chromatograph ◽  
Ionization Detector ◽  
Active Ingredients ◽  
Flame Ionization ◽  
Detector Method

Aims: To establish a rapid and simultaneous determination of multiple effective ingredients in anti-cold drugs. Background: Anti-cold drugs are stock medicines at home, and most anti-cold formulations are compound preparations. Although the active ingredients of compound preparations have significant effects on the treatment of colds, the excessive dosage or long-term use can produce a series of adverse reactions including dependence, liver and kidney function damage, digestive system reaction, blood system damage. Now, there are many mature methods for analyzing the active ingredients of anti-cold drugs. However, these methods may have shortcomings such as a long analysis time or a small number of analysis components. Objective: Establish a gas chromatography-flame ionization detector method for the simultaneous determination of six active ingredients including acetaminophen, dextromethorphan hydrobromide, pseudoephedrine hydrochloride, chlorpheniramine maleate, diphenhydramine hydrochloride, and caffeine in anti-cold drugs. Method: After the standard was accurately weighed, dissolved in ethanol, filtered by 0.22 μm membrane and ultrasonically degassed, the gas chromatograph was used for detection. After the actual sample was removed from the coating, ground and crushed, accurately weighed, dissolved in ethanol, filtered by 0.22 μm membrane and ultrasonically degassed, the gas chromatograph was used for detection. Result: The six components can be completely separated within 7.0min. This method has good sensitivity, precision, accuracy and recovery rate. Under the optimum testing conditions, the limit of detection was 0.360-2.50μg/mL, the limit of quantification was 1.20-8.30μg/mL. The calibration curves showed good linearity (R2≥0.9932) over the investigated concentration range between 1.20 and 400μg/mL. The recoveries were 89.2% to 109.2%. The RSD of intra-day precision was less than 1.0%. The RSD of inter-day precision was less than 3.2%. The established method was used to determine the ingredients of three anti-cold drugs on the market, and the results showed that the method can accurately determine the ingredients. Conclusion: The method can quickly and simultaneously determine multiple active ingredients in anti-cold medicines. Compared with the published methods in literatures, the proposed method has the advantages of fast, the number of analysis componentswide application range, convenience, low cost, etc. It provides a reference method for quality control of active ingredients of anti-cold drugs.

Rapid Determination of Total Cholesterol in Homogenized Milk

1989 ◽  
Vol 72 (3) ◽  
pp. 421-424 ◽  
Author(s):  
Ida C Tsui
Keyword(s):  
Total Cholesterol ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Rapid Determination ◽  
Internal Standard ◽  
Gas Chromatograph ◽  
Relative Standard ◽  
Aoac Method ◽  
Normal Work

Abstract A rapid method that is amenable to automation has been developed for the determination of total cholesterol in homogenized milk. The milk sample is saponified in ethanolic KOH in the presence of an internal standard, cholestane. Cholesterol and the internal standard are then isolated by solid-phase extraction on a nonpolar adsorbent and eluted with organic solvent. The evaporated extract is derivatized and analyzed by capillary gas chromatography. Average recovery of cholesterol acetate added to milk prior to saponification was 95%. The average relative standard deviation for repeated analyses was 2%. The limit of detection for this method is 2 mg/100 g. Twenty samples can be analyzed by one analyst in a normal work day if the gas chromatograph is equipped with an autosampler. This method has been compared with a modified AOAC method for the determination of total cholesterol. At a confidence level of 95%, no difference was observed between the 2 methods.

Determination of Trifluralin in Formulations by Gas Chromatography

1971 ◽  
Vol 54 (1) ◽  
pp. 125-127
Author(s):  
Larry G Hambleton
Keyword(s):  
Gas Chromatography ◽  
Chromatographic Method ◽  
Internal Standard ◽  
Flame Ionization Detector ◽  
Gas Chromatograph ◽  
Ionization Detector ◽  
Average Recovery ◽  
Flame Ionization ◽  
Gas Chromatographic Method

Abstract A gas chromatographic method has been developed that is rapid and specific for trifluralin in formulations. The sample is extracted with acetone, an internal standard is added, and the solution is diluted to volume and injected into a gas chromatograph equipped with a flame ionization detector. Three typical trifluralin formulations were analyzed by both the gas chromatographic method and an ultraviolet method. The gas chromatographic method gave an average recovery of 101.2%.

Establishment and Validation of a Sensitive Method for the Detection of Pregabalin in Pharmacological Formulation by GC/MS Spectrometry

2019 ◽  
Vol 15 (2) ◽  
pp. 165-171 ◽  
Author(s):  
Wael Abu Dayyih ◽  
Mohammed Hamad ◽  
Eyad Mallah ◽  
Alice Abu Dayyih ◽  
Kenza Mansoor ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Pharmaceutical Preparations ◽  
Validation Parameters ◽  
Limit Of Quantitation ◽  
Pharmacological Preparation ◽  
Gas Chromatography Mass Spectroscopy ◽  
Anticonvulsant Activities

Background: A gas chromatography and mass spectrometry (GC/MS) procedure was developed and validated for the evaluation and quantification of pregabalin (PGN) in pharmaceutical preparations. </P><P> Introduction: Pregabalin is a γ-amino-n-butyric acid derivative used as an antiepileptic drug for the management of fibromyalgia, and has analgesic, anxiolytic, and anticonvulsant activities. Few studies have been reported on the determination of PGN content in pharmaceutical preparations involving gas chromatography - mass spectroscopy. Methods: Pregabalin was extracted with MSTFA/NH4F/β- mercapto-ethanol at 60°C for 30 min. The acquired derived molecule of pregabalin was identified by specific ion monitoring mode applying the analytical ions m/z 232 and 331. Propranolol was used as Internal Standard (IS). The following validation parameters were taken into consideration: precision, linearity, accuracy, stability, specificity, robustness, ruggedness, Limit Of Detection (LOD) and Limit Of Quantitation (LOQ). Results: The method was selective, precise, sensitive, linear and specific. The linearity of the method was between 3.5 and 300 ng/ml. The precise values were ≤ 3.62% of both intra- and interday validation. The LOD accurate values for Intraday and interday validation were in the range of -0. 25 -2.05%. While LOQ accurate values for intraday and interday were 1.5x10-6 and 3.5 x10-6mg/ml, respectively. Conclusion: Therefore, the developed GC-MS method was effectively implemented to identify PGN in a pharmacological preparation.

Electron-capture gas chromatography as a sensitive method for measuring subnanogram amounts of cholesterol in saliva and urine

1990 ◽  
Vol 36 (3) ◽  
pp. 519-521 ◽  
Author(s):  
H A Schwertner ◽  
E R Johnson ◽  
T E Lane
Keyword(s):  
Gas Chromatography ◽  
Electron Capture ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Cholesterol Concentration ◽  
Tissue Samples ◽  
Flame Ionization ◽  
Low Concentrations ◽  
Coefficients Of Variation ◽  
Sensitive Method

Abstract This is a sensitive method, suitable for measuring subanogram amounts of cholesterol. Cholesterol and the internal standard, epicoprostanol (5-beta-cholestan-3-alpha-ol), are derivatized with pentafluorobenzoyl chloride and detected by electron-capture gas chromatography. The pentafluorobenzoyl esters of cholesterol and the internal standard are easily formed and possess excellent chromatographic and electron-capturing properties. The lower limit of detection of the method, approximately 100 pg injected, is about 500-fold as sensitive as chromatographic methods involving flame-ionization detection. Within-day and between-day coefficients of variation were 4.2% and 8.2%, respectively, for determinations of a urinary cholesterol concentration of 570 micrograms/L (1.47 mumol/L). Such sensitivity permits analysis for cholesterol in (e.g.) physiological fluids, tissue samples, and cell cultures that contain very low concentrations of cholesterol.

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