Mineral Oil Vacuum Distillation Method for Nitrosamines in Fried Bacon, with Thermal Energy Analyzer: Collaborative Study

1982 ◽  
Vol 65 (6) ◽  
pp. 1319-1332
Author(s):  
Earl L Greenfield ◽  
Wertice J Smith ◽  
Anthony J Malanoski ◽  
◽  
M Benson ◽  
...  
Keyword(s):  
Thermal Energy ◽  
Vacuum Distillation ◽  
Collaborative Study ◽  
Mineral Oil ◽  
Distillation Method ◽  
Energy Analyzer ◽  
Coefficients Of Variation

Abstract Nine laboratories participated in a collaborative study of a method for determining 6 nitrosamines, dimethylnitrosamine, diethylnitrosamine, dibutylnitrosamine, nitrosopiperidine, nitrosopyrrolidine, and nitrosomorpholine, in the 5-17 ppb range. The coefficients of variation for repeatability were 10.8, 8.5,10.4, 8.5, 8.7, and 7.8% with corresponding coefficients of variation for reproducibility of 16.4, 12.0,13.6,10.8,11.2, and 10.3% and recoveries of 89.6, 91.6, 84.7, 90.0, 89.6, and 88.1%, respectively. The method was adopted official first action.

Comparison of Three Methods for Determination of /V-Nitrosopyrrolidine in Fried Dry-Cured and Pump-Cured Bacon

1988 ◽  
Vol 71 (3) ◽  
pp. 504-508
Author(s):  
Anthony J Malanoski ◽  
Wertice J Smith ◽  
Thomas Phillipo
Keyword(s):  
Low Temperature ◽  
Thermal Energy ◽  
Validation Studies ◽  
Vacuum Distillation ◽  
Mineral Oil ◽  
Energy Analyzer ◽  
Coefficients Of Variation ◽  
The Individual

Abstract Three methods, the mineral oil distillation (MOD), the dry column (DC), and a low temperature vacuum distillation (LTVD), for the determination of iV-nitrosopyrrolidine in dry-cured and pump-cured bacon were compared. Each method uses the thermal energy analyzer for the determinative step. The coefficients of variation for repeatability were 10.3% (MOD), 7.2% (DC), and 9.1% (LTVD) for the dry-cured bacon study and 8.7% (MOD), 8.5% (DC), and 7.1% (LTVD) for the pump-cured bacon study. The pooled coefficients of variation for between-method reproducibility were 11.8% for the drycured bacon and 10.8% for the pump-cured bacon. The pooled coefficients of variation for repeatability were 9.0% for the dry-cured bacon and 8.2% for the pump-cured bacon. These values compare favorably with the values from previous collaborative or validation studies of the individual methods, and the methods can be considered to be equivalent

Dry Column-Thermal Energy Analyzer Method for Determining N-Nitrosopyrrolidine in Fried Bacon: Collaborative Study

1984 ◽  
Vol 67 (3) ◽  
pp. 521-525
Author(s):  
Walter Fiddler ◽  
John W Pensabene ◽  
Robert A Gates ◽  
John G Phillips ◽  
◽  
...  
Keyword(s):  
Thermal Energy ◽  
Collaborative Study ◽  
Internal Standard ◽  
Mineral Oil ◽  
Energy Analyzer ◽  
High Group ◽  
Average Recovery ◽  
Column Method ◽  
Coefficients Of Variation ◽  
Repeatability And Reproducibility

Abstract A dry column method for isolating N-nitrosopyrrolidine (NPYR) from fried, cure-pumped bacon and detection by gas chromatography-thermal energy analyzer (TEA) was studied collaboratively. Testing the results obtained from 11 collaborators for homogeneous variances among samples resulted in splitting the nonzero samples into 2 groups of sample levels, each with similar variances. Outlying results were identified by AOAC-recommended procedures, and laboratories having outliers within a group were excluded. Results from the 9 collaborators remaining in the low group yielded coefficients of variation (CV) of 6.00% and 7.47% for repeatability and reproducibility, respectively, and the 8 collaborators remaining in the high group yielded CV values of 5.64% and 13.72%, respectively. An 85.2% overall average recovery of the N-nitrosoazetidine internal standard was obtained with an average laboratory CV of 10.5%. The method has been adopted official first action as an alternative to the mineral oil distillation-TEA screening procedure.

Determination of N-Nitrosodimethylamine in Nonfat Dry Milk: Collaborative Study

1984 ◽  
Vol 67 (2) ◽  
pp. 232-236
Author(s):  
Nrisinha P Sen ◽  
Stephen Seaman ◽  
K Karpinsky ◽  
◽  
M Castegnaro ◽  
...  
Keyword(s):  
Thermal Energy ◽  
Collaborative Study ◽  
Sulfamic Acid ◽  
Complete Data ◽  
Energy Analyzer ◽  
Coefficients Of Variation ◽  
Dry Milk ◽  
Repeatability And Reproducibility ◽  
Nonfat Dry Milk

Abstract Ten laboratories participated in a collaborative study of a method for the determination of JV-nitrosodimethylamine (NDMA) in nonfat dry milk. NDMA is eluted with dichloromethane from a mixture of Celite, acidic sulfamic acid, and nonfat dry milk (all packed in a chromatography column), concentrated in a Kuderna-Danish concentrator, and finally analyzed by a GC-thermal energy analyzer technique. Ten samples were studied: 6 were naturally contaminated (NDMA levels 0.38- 3.56 ppb) and 4 were spiked with known levels (0.96 and 3.2 ppb) of NDMA. The coefficients of variation (CV) of the complete data for the naturally contaminated samples (excluding the 2 samples containing the lowest levels) were 8.5% and 22.5% for repeatability and reproducibility, respectively. The corresponding CVs for the spiked samples were 14.4% and 20.4%, respectively. The percent recoveries of the added NDMA in the spiked samples (at the 2 levels indicated above) were 101.6 ± 3.2 (omitting 1 outlier) and 95 ∓ 2.1, respectively. The method has been adopted official first action.

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%.

Gas-Liquid Chromatographic-Thermal Energy Analyzer Determination of N-Nitrosodimethylamine in Beer: Collaborative Study

1982 ◽  
Vol 65 (3) ◽  
pp. 720-729
Author(s):  
Nrisinha P Sen ◽  
Stephen Seaman ◽  
Mikelis Bickis ◽  
◽  
M Castegnaro ◽  
...  
Keyword(s):  
Thermal Energy ◽  
Collaborative Study ◽  
Variance Analysis ◽  
Energy Analyzer ◽  
Laboratory Sample ◽  
Coefficients Of Variation ◽  
Percent Recovery ◽  
Repeatability And Reproducibility ◽  
Liquid Chromatographic

Abstract The GLC/TEA method for N-nitrosodimethylamine (NDMA) in beer was studied collaboratively by 13 laboratories from 7 countries. Collaborators were asked to analyze a total of 10 randomly labeled samples of beer consisting of the following duplicates: a naturally contaminated commercial beer; a beer extremely low (ca 0.1 ppb) in NDMA; and the low NDMA beer spiked with 0.5,1.9, and 5.0 ppb NDMA. The pooled repeatability and reproducibility coefficients of variation (CV) for all samples were 17% and 27%, respectively. However, when data from 2 laboratories (outliers) were omitted, the corresponding CV values improved considerably (11% and 15%, respectively). Variance analysis showed the presence of a significant laboratory-sample interaction when all data were used for analysis, but this interaction disappeared when data from the 2 outlying laboratories were excluded. The pooled percent recovery of the overall method (omitting outliers) was 101.4 ± 3.5. All the laboratories detected NDMA in the low NDMA beer. The method was adopted official first action.

Determination of /V-Nitrosodipropylamine in Trifluralin Emulsifiable Concentrates Using Minicolumn Cleanup and Gas Chromatography with Thermal Energy Analyzer

1988 ◽  
Vol 71 (2) ◽  
pp. 333-336
Author(s):  
Dave Wotherspoon ◽  
Ralph Hindle
Keyword(s):  
Gas Chromatography ◽  
Thermal Energy ◽  
Internal Standard ◽  
Energy Analyzer ◽  
Quick Method ◽  
Coefficients Of Variation ◽  
Significant Difference ◽  
Artifact Formation ◽  
And Control

Abstract A quick method for determining /V-nitrosodipropylamine (NDPA) levels in trifluralin emulsifiable concentrate formulations is described. At least 18 samples can be analyzed at one time in a minimum of fumehood space, with up to 90% savings on solvents and materials. A sample aliquot is mixed with a solution containing nitrosamine recovery standards, and nitrosamines are separated by minicolumn cleanup. Internal standard is added directly to the eluate containing the nitrosamines, and levels are determined by gas chromatography with thermal energy analyzer. Recoveries of spiked nitrosamines ranged from 98 to 102%. Coefficients of variation for samples containing 0.5 ppm NDPA are 13%. Minimum detectable limit, calculated as 3 times the noise, is 0.06 ppm. Comparison with the method formerly used by this laboratory shows no significant difference in the analytical results at 95% confidence limits, and control experiments were performed to ensure that there was no artifact formation of NDPA.

Collaborative Study of Improvements in the Distillation Procedure of the Official Method for Formaldehyde in Maple Sirup

1973 ◽  
Vol 56 (1) ◽  
pp. 132-134
Author(s):  
Calixte Hébert
Keyword(s):  
Collaborative Study ◽  
Official Method ◽  
Distillation Method ◽  
Modified Method ◽  
Quantitative Extraction ◽  
Coefficients Of Variation ◽  
Excellent Control ◽  
Final Operation

Abstract A collaborative study was conducted to show that in the quantitative extraction of formaldehyde from maple sirup by the official final action controlled distillation method, 31.184—31.189, accuracy is increased by the use of a thermostatically controlled flask heater, together with the proper insulation of the glass apparatus with asbestos cord. This eliminates undue condensation of the distillate and variations in the final and total distillation times. The modified method was tested by 9 laboratories and, from their individual results, the coefficients of variation for the total time of distillation proved that the method gave excellent control of the final operation. The changes have been adopted as official first action.

Oil Flotation Extraction of Light Filth from Ground Capsicums Excluding Paprika: Collaborative Study

1978 ◽  
Vol 61 (4) ◽  
pp. 900-902
Author(s):  
Joel J Thrasher ◽  
Emma Jean Colliflower
Keyword(s):  
Collaborative Study ◽  
Fold Increase ◽  
Mineral Oil ◽  
Improved Method ◽  
Coefficients Of Variation ◽  
Filter Papers ◽  
Collaborative Tests ◽  
Wet Sieving

Abstract A collaborative study has been completed on an improved method for the isolation of light filth from ground capsicums other than paprika. The proposed method involves isopropanol pretreatment, wet-sieving, and extraction from cooled 6 0% ethanol with a mineral oil-heptane mixture. The collaborative tests by the proposed method showed an approximate 2-fold increase in recoveries of insect fragments and rodent hairs with acceptable coefficients of variation and clean filter papers. The proposed method has been adopted as official first action to replace 44.123.

Determination of Nitrate in Dried Foods by Gas Chromatography-Thermal Energy Analyzer

1985 ◽  
Vol 68 (1) ◽  
pp. 41-43
Author(s):  
Holly D Ross ◽  
Joseph H Hotchkiss
Keyword(s):  
Gas Chromatography ◽  
Ethyl Acetate ◽  
Thermal Energy ◽  
Energy Analyzer ◽  
Gas Chromatograph ◽  
Coefficients Of Variation ◽  
Dry Milk ◽  
Nonfat Dry Milk ◽  
Dried Foods

Abstract The method described for determining N03~ in dried foods is based on extraction of N03~ from the sample with subsequent nitration of benzene. The nitrobenzene is extracted with ethyl acetate, analyzed by using a gas chromatograph-thermal energy analyzer (GC-TEA), and quantitated against a nitrobenzene standard. Sensitivity is 100-200 μg/ kg. Coefficients of variation for analyses of dried foods were 3-13%. Recovery of N03" from nonfat dry milk spiked at 10 mg/kg averaged 100%.

High Temperature Purge and Trap Procedure for Determining Seven Volatile N-Nitrosamines in Animal Feed, Using Gas Chromatography/Thermal Energy Analyzer

1984 ◽  
Vol 67 (3) ◽  
pp. 557-562
Author(s):  
Stanley M Billedeau ◽  
Harold C Thompson ◽  
Eugene B Hansen ◽  
Barbara J Miller
Keyword(s):  
Gas Chromatography ◽  
High Temperature ◽  
Thermal Energy ◽  
Animal Feed ◽  
Mineral Oil ◽  
Nitroso Compounds ◽  
Energy Analyzer ◽  
Purge And Trap ◽  
Multiple Sample ◽  
Feed Samples

Abstract A rapid and sensitive procedure is described for determining 4 N- nitrosodialkylamines (dimethyl, diethyl, dipropyl, and dibutyl) and the N-nitroso analogs of piperidine, pyrrolidine, and morpholine in animal feed. The volatile N-nitrosamines were isolated by using a modified high temperature purge and trap apparatus designed for multiple sample cleanup. The feed sample was mixed with mineral oil and a nitrosation inhibitor, and the N-nitrosamines were purged onto a ThermoSorb/N cartridge, eluted with acetone–dichloromethane (1 + 1), and determined by gas chromatography, using a thermal energy analyzer. The effects of purge rate, purge time, and temperature on recovery are discussed. Feed samples spiked with 10, 50, and 200 ppb of the 7 N-nitroso compounds yielded recoveries ranging from 70 to 97%, with precision ranging from 1.3 to 5.4% and minimum detectable levels in the low parts-per-billion range.

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