Determination of /V-Nitrosodiethanolamine in Dinoseb Formulations by Mass Spectrometry and Thermal Energy Analyzer Detection

1987 ◽  
Vol 70 (5) ◽  
pp. 792-796
Author(s):  
Yuk Y Wigfield ◽  
Narine P Gurprasad ◽  
Monique Lanouette ◽  
Sharon Ripley
Keyword(s):  
Thermal Energy ◽  
Methylene Chloride ◽  
Limit Of Detection ◽  
Solvent System ◽  
Energy Analyzer ◽  
Liquid Chromatograph ◽  
Anion Exchange Column ◽  
Exchange Column ◽  
Cation Exchange Column ◽  
In Series

Abstract A new method is described to determine trace quantities of A'-nitrosodiethanolamine (NDE1A) in aqueous diethanolamine (DE1A) formulations and in oil solutions of dinoseb. A formate anion-exchange column is used in series with a cation-exchange column if there is DE1A in the formulation. The eluate is then passed through a Clin Elur8 column. Depending on the concentration of NDE1A in the sample, a packed silica-gel column is used to purify the extract further. This extract is analyzed on a liquid chromatograph coupled with a thermal energy analyzer (LC/TEA), using a mixture of methanol- hexane-methylene chloride containing 0.1% acetic acid (8 + 56 + 35) as the mobile phase. This solvent system gives good separation of NDE1A from trace quantities of dinoseb remaining in the extract. The NDE1A is also converted to the trimethylsilyl derivative and analyzed by gas chromatograph coupled with a mass spectrometer (GC/MS). Analyses of 11 commercial samples of dinoseb diethanolamine salt showed NDE1A levels of 116-2409 ppm expressed relative to the weight of dinoseb. In contrast, analyses of 2 samples of organic solutions of technical dinoseb showed NDE1A levels to be nondetectable and 0.3 ppm, respectively. Limit of detection by LC/ TEA is 6.5 ng (0.5 ppm), and by GC/MS it is 0.02 ng (0.15 ppm). Recoveries from samples spiked at 0.514-1664 ppm range from 92.2 to 105.2%

Screening Procedure for Detection of Volatile AT-Nitrosamines in Cooked Bacon by One-Trap Mineral Oil Vacuum Distillation and Thermal Energy Analyzer

1982 ◽  
Vol 65 (6) ◽  
pp. 1316-1318 ◽  
Author(s):  
Earl L Greenfield ◽  
G A Vasco ◽  
L Legette ◽  
Anthony Malanoski
Keyword(s):  
Liquid Nitrogen ◽  
Thermal Energy ◽  
Vacuum Distillation ◽  
Methylene Chloride ◽  
Mineral Oil ◽  
Rapid Screening ◽  
Screening Procedure ◽  
Energy Analyzer ◽  
Liquid Chromatograph

Abstract A rapid screening procedure for the detection of volatile N-nitrosamines in fried bacon has been developed for the regulatory monitoring of bacon. This procedure uses vacuum mineral oil distillation of an alkaline sample. The distillate is collected in a prewet trap immersed in liquid nitrogen. After thawing, the distillate is transferred to a separator. The trap is rinsed with methylene chloride which is then used to extract the nitrosamines. The methylene chloride is dried with Na2S04 and concentrated. A gas-liquid chromatograph coupled to a thermal energy analyzer is used to identify and quantitate the nitrosamines. Recoveries of 7 volatile N-nitrosamines added to 25 g fried bacon at the 10 ppb level (μg/kg) ranged from 78 to 92%.

Rapid Gas Chromatographic Method for Determining Ethyl Carbamate in Alcoholic Beverages with Thermal Energy Analyzer Detection

1988 ◽  
Vol 71 (3) ◽  
pp. 509-511
Author(s):  
Canas Benjamin J ◽  
Donald C HaVery ◽  
Frank L Joe
Keyword(s):  
Mass Spectrometry ◽  
Thermal Energy ◽  
Methylene Chloride ◽  
Limit Of Detection ◽  
Ethyl Carbamate ◽  
Alcoholic Beverages ◽  
Gas Chromatography Mass Spectrometry ◽  
Energy Analyzer ◽  
Elution Method ◽  
Gas Chromatographic Method

Abstract A rapid column elution method has been developed for the determination of ethyl carbamate (EC) in alcoholic beverages. The beverage is mixed with Celite and packed in a column containing deactivated alumina capped with a layer of sodium sulfate. EC is then eluted with methylene chloride. The method, using a gas chromatograph- thermal energy analyzer with a nitrogen converter for detection and quantitation of EC, has been applied to a variety of alcoholic beverages. Recoveries ± standard deviations of EC in wine and whisky fortified at the 20 and 133 µg/kg (ppb) levels averaged 87.3 ± 5.3 and 88.7 ± 3.6%, respectively. The method has a limit of detection of 1.5 ppb. Gas chromatography/mass spectrometry/ mass spectrometry was used to confirm the identity and quantitation of EC in selected beverage extracts.

scholarly journals Ion Chromatographic Method for the Simultaneous Determination of Anions and Cations in Firecrackers and Matches Samples as Known Potential Explosives

2019 ◽  
Vol 15 (1) ◽  
pp. 138
Author(s):  
Muhammad Amin ◽  
Lee Wah Lim
Keyword(s):  
Cation Exchange ◽  
Anion Exchange ◽  
Mobile Phase ◽  
Limit Of Detection ◽  
Reference Method ◽  
Anion Exchange Column ◽  
Exchange Column ◽  
Relative Standard ◽  
Cation Exchange Column

<p class="Abstract">A reference ion chromatography method based on column switching has been presented for the simultaneous determining anions (Cl<sup>−</sup>, ClO<sub>3</sub><sup>−</sup>, NO<sub>2</sub><sup>−</sup>, SO<sub>4</sub><sup>2</sup><sup>−</sup>, and NO<sub>3</sub><sup>−</sup>) and/or cations (NH<sub>4</sub><sup>+</sup>, Na<sup>+</sup>, K<sup>+</sup>, Ca<sup>2+</sup>, and Mg<sup>2+</sup>) using one pump, one type of mobile phase, and one detector. The reference method performed anion-exchange column and cation-exchange column and arranged serially via one 10-port valve. The determination of either anions or cations in one determination system could be made by switching the valve. When the use of 1.25 mM trimellitic acid as a mobile phase and the instrument was operated at a flow rate of 0.6 mL/min, five anions and five cations were determined on the anion-exchange column and the cation-exchange column, respectively. All anions target could be determined completely within 55 minutes, whereas the cations target could be determined within 35 minutes. The calculation of limit of detection using S/N=3 was 3.85 − 14.10 µM for anions and 2.95 − 10.58 µM for cations. The relative standard deviations of all ions were less than 3.82%, 3.29%, and 3.21% for retention time, peak area, and peak height, respectively. The reference method was then applied for the simultaneous determining anions and/or cations contained in firecrackers and matches samples as known potentially explosives.</p>

scholarly journals The formation of volatile N-nitrosamines in laboratory-scale grass and maize silages.

1985 ◽  
Vol 33 (1) ◽  
pp. 17-22 ◽  
Author(s):  
L.W. van Broekhoven ◽  
J.A.R. Davies
Keyword(s):  
Thermal Energy ◽  
Limit Of Detection ◽  
Laboratory Scale ◽  
Energy Analyzer ◽  
Fertilizer Regimes

Fresh grass and maize samples from experimental fields with different fertilizer regimes were ensiled in the laboratory in glass preserving jars. The resulting silages were analysed for the presence of volatile N-nitrosamines with a Thermal Energy Analyzer. In the grass silages, up to 4 micro g N-nitrosodimethylamine (NDMA)/kg was found. In the maize silages no NDMA was found above the limit of detection (0.2 micro g/kg). (Abstract retrieved from CAB Abstracts by CABI’s permission)

High Pressure Liquid Chromatographic-Thermal Energy Determination of N-Nitrosodiethanolamine in Cosmetics

1981 ◽  
Vol 64 (4) ◽  
pp. 800-804 ◽  
Author(s):  
Julia L Ho ◽  
Harris H Wisneski ◽  
Ronald L Yates
Keyword(s):  
High Pressure ◽  
Thermal Energy ◽  
Limit Of Detection ◽  
Gradient Elution ◽  
Gas Chromatography Mass Spectrometry ◽  
Detector Response ◽  
Product Analysis ◽  
Liquid Chromatograph ◽  
Silyl Derivative ◽  
Cosmetic Product

Abstract Methods for the determination and confirmation of N-nitrosodiethanolamine (NDELA) in cosmetic products were developed. The NDELA fraction was isolated from a cosmetic product by a series of solvent extractions which were designed to concentrate the NDELA and remove ingredients deleterious to the analytical system. The isolated fraction was then analyzed for NDELA using a high pressure liquid chromatograph (HPLC) interfaced with a thermal energy analyzer (TEA). The compound was measured by comparison of detector response with those of known standards. NDELA was verified by gas chromatography-mass spectrometry of the silyl derivative after preliminary cleanup of the sample by gradient elution HPLC on a Partisil 10 PAC column. The limit of detection of NDELA by TEA is 2-3 ng, which corresponds to 20-30 ppb in the cosmetic product. Analysis of an emulsion cream and a hair grooming gel spiked at 3 and 4 ng concentration levels, respectively, yielded recoveries ranging from 71 to 103% (average 88%).

Quantitation of the Nitrosamine 2-EthylhexyI-4-(N-Methyl-N-Nitrosoamino) Benzoate (NPABAO) in Sunscreen Products

1991 ◽  
Vol 74 (5) ◽  
pp. 766-771 ◽  
Author(s):  
Thomas A Meyer ◽  
Jimmy B Powell
Keyword(s):  
Thermal Energy ◽  
False Positive ◽  
Mobile Phase ◽  
Commercial Product ◽  
Energy Analyzer ◽  
Accurate Analysis ◽  
Liquid Chromatograph ◽  
Commercial Products ◽  
Minimum Detectable Limit ◽  
Sunscreen Products

Abstract We have devised a method to quantitate the nitrosamine, 2- ethylhexyM-(N-methyl-N-nitrosoamino) benzoate (NPABAO), In commercial products containing the sunscreen ingredient, Padimate 0. The method involves a minimum of cleanup steps to afford a nonaqueous extract from product emulsions suitable for analysis by a liquid chromatograph Interfaced to a thermal energy analyzer (LC/TEA). The method Is applicable to lotions, creams, and gels. Oils are normally soluble In the mobile phase and can be analyzed directly on the LC/TEA without additional cleanup procedures. The method has a minimum detectable limit of about 30 ppb and yields &gt; 80% recovery. It is highly reproducible and generates no NPABAO artifactually prior to quantitation on the LC/TEA Application of the method to 22 different commercial product formulas disclosed that the level of NPABAO in each of the products Is below 250 ppb, with 18 of the products containing less than 100 ppb. Of interest was the observation that musk ketone, a common fragrance constituent, produces a false-positive TEA response that can Interfere with accurate analysis of NPABAO content In typical commercial products

Gas Chromatographic Determination of N-Nitrosodialkanolamines in Herbicide Di- or Trialkanolamine Formulations

1988 ◽  
Vol 71 (2) ◽  
pp. 328-333
Author(s):  
Yuk Y Wigfield ◽  
Mario D Lacfloix ◽  
Monique Lanouette ◽  
Narine P Gurprasad
Keyword(s):  
Chromatographic Determination ◽  
Aqueous Sample ◽  
Anion Exchange Column ◽  
Exchange Column ◽  
Modified Method ◽  
Extraction Tube ◽  
Cation Exchange Column ◽  
Aqueous Layer ◽  
Tms Derivatives

Abstract A modified method is presented to determine trace quantities of N-nitrosodiethanolamine (NDE1A) and yV-nitrosodiisopropanolamine (NDiPlA) in the triisopropanolamine (TiPlA) formulation of a mixture of picloram and 2,4-D. Aqueous sample is extracted with dichloromethane to remove organic interferences, and then the aqueous layer is passed sequentially through chloride anion exchange column, hydrogen cation exchange column, and Clin-Elut extraction tube. The final eluate, 10% acetone in ethyl acetate, is concentrated. The isolated nitrosamines are converted to the corresponding trimethylsilyl (TMS) derivatives and determined by gas chromatography (GC) on a DB1 column coupled with a thermal energy analyzer (GC-TEA). Eight samples of commercial TiPlA formulations are analyzed. Maximum detected levels of NDE1A and NDiPlA were 0.6 and 0.9 ppm, respectively, expressed relative to total weight of active ingredients. Analysis of 13 samples of herbicide DEIA formulation using a previously established method and a DB225 column gave NDE1A results of 0.7-6.0 ppm. NDiPlA was not detected in those samples. Results are confirmed by GC-mass spectrometry (GC/MS) with oxygen negative chemical ionization (ONCI) detection. Dectection limits for both nitrosamines are 0.05 or 0.07 ng (0.1 or 0.17 ppm) for GC-TEA detection, depending on the analytical columns used, and 20 pg (0.04 ppm) for GC/MS detection. Recoveries of NDE1A are 87-109% for DEIA formulation spiked at 2.6 and 3.9 ppm and 90-115% for TiPlA formulation spiked at 0.2-0.3 ppm. Similarly, recoveries of NDiPlA are 95.7-100% for the DEIA formulation spiked at 0.24 and 0.48 ppm, and 82-118% for the TiPlA formulation spiked at 0.2-0.3 ppm.

Gas Chromatographic/Chemiluminescence Detection (Thermal Energy Analyzer-Nitrogen Mode) Method for the Determination of Dibutylamine in Hams

1993 ◽  
Vol 76 (3) ◽  
pp. 578-581 ◽  
Author(s):  
Walter Fiddler ◽  
Robert C Doerr
Keyword(s):  
Thermal Energy ◽  
Coefficient Of Variation ◽  
Isopropyl Alcohol ◽  
Energy Analysis ◽  
Limit Of Detection ◽  
Energy Analyzer ◽  
Chemiluminescence Detection ◽  
Mode Method

Abstract A gas chromatographic (GC) procedure is described for the determination of dibutylamine (DBA) in ham at less than 1 ppm. Sample is extracted with 0.5N HCI, centrifuged, made basic, and then extracted with isopropyl alcohol. Final determination is by GC/thermal energy analysis in the nitrogen mode. Six replicate analyses of ham fortified with 0.5 ppm DBA gave a recovery of 90.2 ± 3.4%. Over a range of 0.5 to 3.0 ppm DBA, the repeatability was 0.07 ppm, and the coefficient of variation was 6.07%. Limit of detection was 01 ppm. Effectiveness of the procedure was demonstrated on selected ham samples.

Excretion of L-Dopa and Its Metabolites in Urine of Parkinson's Disease Patients Receiving L-Dopa Therapy

1971 ◽  
Vol 17 (9) ◽  
pp. 867-871 ◽  
Author(s):  
J I Routh ◽  
R E Bannow ◽  
R W Fincham ◽  
J L Stoll
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Cation Exchange ◽  
Anion Exchange ◽  
Paper Electrophoresis ◽  
Colorimetric Determination ◽  
Anion Exchange Column ◽  
Exchange Column ◽  
Cation Exchange Column

Abstract L-Dopa and its major metabolites were separated from daily 24-h urines from patients with Parkinson’s disease, who were being treated with increasing doses of the drug, up to 4 g per day. An aliquot of each sample was passed through three different ion-exchange columns. Catecholamines (dopamine, epinephrine, norepinephrine, metanephrine, and normetanephrine) were retained on a cation-exchange column, eluted with boric acid, and quantitated by fluorometric analysis. Catechol acids, present in the effluent of the cation-exchange column, were retained on an anion-exchange column. An aliquot of the eluate of the anion-exchange column was used for colorimetric determination of 3,4-dihydroxyphenylacetic acid, while the effluent from this column was used for colorimetric determination of dopa. A second aliquot of the eluate from this column was passed over a column of alumina, which retained all the acidic metabolites except homovanillic acid, which was measured fluorometrically in the effluent from the alumina column. Vanilmandelic acid was determined in another aliquot of each urine sample by use of paper electrophoresis. The excretion pattern elicited suggests a major metabolic pathway for the L-dopa administered to patients with Parkinson's disease.

Residue Analysis of Glyphosate and Its Principal Metabolite in Certain Cereals, Oilseeds,and Pulses by Liquid Chromatography and Postcolumn Fluorescence Detection

1991 ◽  
Vol 74 (5) ◽  
pp. 842-847 ◽  
Author(s):  
Yuk Y Wigfield ◽  
Monique Lanouette
Keyword(s):  
Liquid Chromatography ◽  
Fluorescence Detection ◽  
Residue Analysis ◽  
Anion Exchange Column ◽  
Ground Sample ◽  
Exchange Column ◽  
Coefficients Of Variation ◽  
White Bean ◽  
Cation Exchange Column ◽  
Liquid Chromatographic

Abstract A postcolumn liquid chromatographic method to determine the extractable residues of glyphosate (GLYPH) and its principal metabolite, (amlnomethyQphosphonic acid (AMPA), In various cereals and beans Is described. The finely ground sample Is extracted with a mixture of chloroform and water, and the resulting aqueous layer is passed through a cation exchange column. The eluate is adjusted to pH 7-10 and passed through an anion exchange column. The second column is eluted with 0.3M HCI solution and the resulting acidic eluate Is analyzed with liquid chromatography coupled with postcolumn fluorescence detection. The mean recoveries for GLYPH In barley, canola, dry pea, flax, soybean, wheat, and white bean ranged from 90.9 to 98.1%, with coefficients of variation (CV) from 2.9 to 10.0% and limits of detection (LOD) from 0.07 to 0.14 ppm. Similarly, mean recoveries for AMPA in the same crops ranged from 87.4 to 98.9%, with CV from 4.6 to 7.7% and LOD from 0.05 to 0.12 ppm. Using this method, an analyst can routinely analyze 6 samples per 1.5 days. The advantages of this procedure are discussed

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