Collaborative Study of a New Method for the Extraction of Light Filth from Ground Coffee

1972 ◽  
Vol 55 (1) ◽  
pp. 57-59
Author(s):  
Joel J Thrasher
Keyword(s):  
Hydrogen Peroxide ◽  
Carbon Tetrachloride ◽  
Collaborative Study ◽  
Mineral Oil ◽  
New Method ◽  
Official Method ◽  
Peroxide Bleaching ◽  
Filter Papers ◽  
Analytical Time ◽  
Ground Coffee

Abstract A collaborative study has been completed on a new method for light filth in ground coffee. The sample is defatted with chloroform, dried, and boiled in water; isopropanol is added and the sample is boiled again. Light filth is trapped off with mineral oil from a hot solution. The method yields better recoveries of insect fragments and rodent hairs than the official method. Other advantages are less analytical time, cleaner filter papers, and elimination of the use of carbon tetrachloride. It is recommended that the method be adopted as official first action to replace 40.007(b) for the isolation of light filth from ground coffee and that the hydrogen peroxide bleaching technique described earlier be adopted as a procedure to replace the sodium hypochlorite technique described in 40.006.

Collaborative Study of an Acid Autoclave Method for Mineral Oil Extraction of Light Filth from Spaghetti and Macaroni

1969 ◽  
Vol 52 (3) ◽  
pp. 463-465
Author(s):  
Joel J Thrasher
Keyword(s):  
Collaborative Study ◽  
Mineral Oil ◽  
Oil Extraction ◽  
New Method ◽  
Official Method ◽  
Plain Weave ◽  
Filter Papers ◽  
Wet Sieving ◽  
Better Than

Abstract A method for the extraction of light filth from alimentary pastes based on rapid autoclaving of acidified samples, wet sieving on a No. 230 plain weave sieve, and heating the sieve retainings in an acidic mineral oil mixture is described. This new method is faster and results in higher and more reproducible recoveries than method 36.025. Recoveries were equal or better than those achieved by the official method, and the filter papers were cleaner.

Collaborative Study of a New Method for Extraction of Light Filth from Reconditioned (Coarsely Ground) Nutmeg

1971 ◽  
Vol 54 (3) ◽  
pp. 575-578
Author(s):  
Alberto W Vazquez
Keyword(s):  
Collaborative Study ◽  
Mineral Oil ◽  
New Method ◽  
Official Method ◽  
Collaborative Testing

Abstract A new method has been developed for extraction of light filth from coarsely ground nutmeg. Nutmeg tissue is defatted by 3 successive 10 min extractions with boiling CHCI3, after which the solvent is removed by aspiration and an isopropanol rinse. Following sieving on a No. 230 sieve and a brief deaeration and hydrolysis step in acidified boiling 60% ethanol-CaCl2, light filth elements are extracted with mineral oil from the 60% ethanol-CaCl2 mixture. Collaborative testing of the proposed method yielded satisfactory recoveries of added light filth elements. The official method for ground spices, 40.106(b), was compared in a collaborative study with the proposed method for the analysis of ground nutmeg and mace. Results were encouraging, but further study is indicated. The method as described for reconditioned nutmeg has been adopted as official first action.

Collaborative Study of a Method for the Extraction of Light Filth from Ground Mace and Ground Caraway Seed

1976 ◽  
Vol 59 (4) ◽  
pp. 827-829
Author(s):  
Joel J Thrasher
Keyword(s):  
Collaborative Study ◽  
Mineral Oil ◽  
New Method ◽  
Filter Papers

Abstract A new method has been developed for the extraction of light filth from ground mace and ground caraway seed. The method uses a 2-step chloroform-isopropanol pretreatment followed by separation of the light filth from 40% isopropanol with mineral oil. The collaborative study resulted in clean filter papers with more reproducible recoveries of light filth elements than the official first action method, 44.116(b). The method has been adopted as official first action.

Extraction of Light Filth from Tea: Collaborative Study

1981 ◽  
Vol 64 (2) ◽  
pp. 287-290
Author(s):  
Faith F Lim ◽  
◽  
J Barnett ◽  
A Bright ◽  
M P Chaput ◽  
...  
Keyword(s):  
Sample Preparation ◽  
Collaborative Study ◽  
Tween 80 ◽  
Mineral Oil ◽  
Plant Residue ◽  
Official Method ◽  
Existing Problems ◽  
Aoac Method ◽  
Filter Papers ◽  
Wet Sieving

Abstract The present AOAC method for determining insect and rodent filth in tea is time-consuming because it produces filter papers which are heavy in plant residue and therefore requires long paper-reading times. Anew method for the analysis of light filth in tea was developed to remedy existing problems and to improve recoveries. The method consists of the following steps: sample preparation, wet sieving, dilution with 40% isopropanol, extraction with Tween 80-Na4EDTA-40% isopropanol, flotation with mineral oil-heptane, and trapping off in a Wildman trap flask. In an interlaboratory collaborative study, analysts reported combined insect fragment recoveries of 99.2% for the proposed method and 93.0% for the AOAC method; the same analysts recorded combined rodent hair recoveries of 92.2% for the proposed method and 47.6% for the official method. Average times for reading individual subsamples were 9 min for the proposed method and 27 min for the AOAC method. The proposed method has been adopted official first action.

Collaborative Study of a New Method for the Extraction of Light Filth from Black and White Ground Pepper

1972 ◽  
Vol 55 (1) ◽  
pp. 83-84
Author(s):  
Russell G Dent ◽  
Paris M Brickey
Keyword(s):  
Collaborative Study ◽  
Mineral Oil ◽  
New Method ◽  
Black And White ◽  
Collaborative Studies ◽  
Filter Papers ◽  
Pepper Sample

Abstract In the method described, the black or white ground pepper sample is slurried with water and wet sieved. The pepper residue is defatted during the sieving step. Flotation extraction of the sieved material utilizes a combination of n-heptane-mineral oil as the oil layer over 40% isopropanol. Collaborative studies resulted in reproducible recoveries and light-to-medium laden filter papers. It is recommended that the method be adopted as official first action to replace 40.109(b).

Collaborative Study of a Method for the Extraction of Light Filth from Ground Chicory

1971 ◽  
Vol 54 (3) ◽  
pp. 571-572
Author(s):  
J J Thrasher
Keyword(s):  
Collaborative Study ◽  
New Method ◽  
Official Method ◽  
Average Recovery ◽  
Paraffin Oil ◽  
Filter Papers ◽  
Wet Sieving

Abstract Collaborative results are presented on a new method for light filth in ground chicory. A comparison of the new method and the official method, 40.007(b), indicates that recoveries of spiked larvae and adult insects were approximately equal for the 2 methods. However, average recovery of rodent hairs by the proposed method was 86% while rodent hair recovery by the official method was 55%. The new method utilizes detergent digestion and wet sieving followed by flotation with paraffin oil from 40% isopropanol. It is less time consuming to perform and cleaner filter papers are obtained. The new method has been adopted as official first action.

Extraction of Light Filth from Ground Nutmeg: Collaborative Study

1979 ◽  
Vol 62 (3) ◽  
pp. 595-596
Author(s):  
Joel J Thrasher
Keyword(s):  
Plant Material ◽  
Collaborative Study ◽  
Mineral Oil ◽  
New Method ◽  
Official Method ◽  
Additional Problem

Abstract The official method for extracting light filth from ground nutmeg, 44.116, gives variable recoveries of filth elements and results in large amounts of interfering plant material in the light filth extraction. A new method has been developed using a chloroform pretreatment for heavy filth followed by a water-40% isopropanol- mineral oil flotation of light filth. A comparison of the methods in the collaborative study showed a higher recovery of insect fragments, 90.6 vs. 65.2%, and of rodent hairs, 86.5 vs. 66.5%, for the new method over the present official first action method, 44.116. Frothing, an additional problem with the official method, has been reduced by the new method. The new method has been adopted as official first action to replace the existing method.

Mineral Oil Extraction of Light Filth from Rubbed Sage Collaborative Study

1979 ◽  
Vol 62 (3) ◽  
pp. 597-599
Author(s):  
Emma J Colliflower ◽  
Joel J Thrasher
Keyword(s):  
Plant Material ◽  
Collaborative Study ◽  
Tween 80 ◽  
Mineral Oil ◽  
Oil Extraction ◽  
New Method ◽  
Filter Papers

Abstract The official methods for extracting light filth from rubbed sage, 44.D08–44.D10, specifies a hot isopropanol pretreatment and flotation from cooled dilute isopropanol with mineral oil to extract light filth. The method gives good recoveries, but occasionally excessive interfering plant material is extracted along with the filth elements. A new method has been developed in which chloroform is used for pretreatment instead of isopropanol, and Tween 80-EDTA is added twice rather than once. This method has given consistently cleaner filter papers and better recoveries for rodent hairs, 85 vs. 79%, and for elytral squares, 95 vs. 84%. The new method has been adopted as official first action.

Extraction of Light Filth from Coconut: Collaborative Study

1978 ◽  
Vol 61 (4) ◽  
pp. 898-899
Author(s):  
Joel J Thrasher
Keyword(s):  
Aqueous Phase ◽  
Sodium Lauryl Sulfate ◽  
Collaborative Study ◽  
Mineral Oil ◽  
Official Method ◽  
Lauryl Sulfate ◽  
Plant Debris ◽  
Filter Papers

Abstract The official method for filth in coconut, 44.029, frequently produces filter papers with excessive plant debris and low hair recoveries. To overcome these deficiencies, 3 changes in the method were made: (1) the defatting step was modified to use sodium lauryl sulfate in combination with borax for better defatting; (2) 40% isopropanol was substituted for 60% ethanol as the aqueous phase for cleaner papers; and (3) mineral oil was substituted for n-heptane to improve hair recoveries. These changes resulted in higher, more reproducible recoveries of rodent hairs and insect fragments and cleaner filter papers. The method has been adopted as official first action to replace 44.029.

New Method for the Extraction of Light Filth from Whole and Granulated Nutmeats

1970 ◽  
Vol 53 (3) ◽  
pp. 553-558
Author(s):  
John S Gecan ◽  
Diane J Howarth ◽  
Paris M Brickey
Keyword(s):  
Acid Hydrolysis ◽  
Calcium Chloride ◽  
Mineral Oil ◽  
New Method ◽  
Official Method ◽  
Coefficients Of Variation

Abstract A new method has been developed which is applicable to all nutmeats, with or without testa, either raw, dry, or oil roasted. Nutmeats are defatted by a 10 min boiling in chloroform (pecans require 3 defattings), after which the solvent is removed by aspiration and an isopropanol rinse. Following a short boiling deaeration and acid hydrolysis, light filth elements are extracted with mineral oil from a mixture of 60% ethanol and calcium chloride. Collaborative trials by the proposed method for nutmeats (except pecans) yielded significantly cleaner extraction papers and better recoveries of all light filth spike elements than by the official method. In addition, the proposed method resulted in reductions of coefficients of variation ranging from 47 to 93% of that for the official method. The modification for pecans, included in this method, required more extensive defatting and also resulted in improved light filth recoveries and reductions in coefficients of variation. Not all varieties of nutmeats were collaboratively studied; however, intralaboratory recovery trials on these nutmeats proved the proposed method superior to the official methods. The method is recommended for adoption as official first.

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