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.

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.

Extraction of Light Filth from Unground Marjoram: Collaborative Study

1985 ◽  
Vol 68 (5) ◽  
pp. 899-901
Author(s):  
Russell G Dent ◽  
Larry Glaze
Keyword(s):  
Microscopic Examination ◽  
Present Method ◽  
Plant Material ◽  
Collaborative Study ◽  
Tween 80 ◽  
Mineral Oil ◽  
Oil Extraction ◽  
Official Method ◽  
Test Portion ◽  
Examination Time

Abstract Ihe present method for filth in unground marjoram is conducted in 2 parts. The first of these, which is for heavy filth and sand, requires the spice to be boiled with petroleum ether, then floated off with chloroform and, if needed, carbon tetrachloride. The second part, which is for light filth, is dependent on completion of the heavy filth section. After the spice is air-dried, the light filth is extracted with heptane and water. The proposed method was developed to make light filth independent of heavy filth analysis, improve filth recoveries, and reduce microscopic examination time. The light filth is extracted by ethanol defatting followed by a combination 15-60% ethanol/mineral oil extraction in a Wildman trap flask. Tween 80-NaEDTA solution is added to the trapping system to reduce the rising of excess plant material to the trap interface. The official method (AOAC 13th edition sees 44.142,44.120(b)) produced an average of 8 extraction papers per test portion and microscopic examination took an average of 88 min per test portion. The official method gave average recoveries of 14% for rodent hairs and 26% for insect fragments with 2 spike levels of 15 and 30 for each filth element. Recoveries of the 2 levels of each spike were not significantly different (P > 0.05). The proposed method gave average recoveries of 73% for rodent hairs and 70% for insect fragments. The proposed method has been adopted official first action to replace AOAC 13th edition sees 44.142 and 44.120(b) for unground marjoram only

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 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 a Method for the Extraction of Light Filth from Canned Fish

1972 ◽  
Vol 55 (1) ◽  
pp. 69-70
Author(s):  
Russell G Dent
Keyword(s):  
Aqueous Phase ◽  
Collaborative Study ◽  
Mineral Oil ◽  
Oil Extraction ◽  
Acid Digestion ◽  
Canned Fish ◽  
Filter Papers

Abstract Collaborative results are presented for a method proposed for light filth extraction from canned fish packed in water, oil, or vegetable sauces. The method utilizes an acid digestion and a hot mineral oil extraction from an aqueous phase in a Corning percolator. Recoveries are reproducible and filter papers are relatively clean. This method is recommended for adoption as official first action to replace procedure 40.064.

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).

Acidic, Mineral Oil Extraction of Light Filth from Bread and Donuts

1970 ◽  
Vol 53 (3) ◽  
pp. 562-566
Author(s):  
Joel J Thrasher
Keyword(s):  
Steam Bath ◽  
Mineral Oil ◽  
Oil Extraction ◽  
New Method ◽  
Filter Papers ◽  
Wet Sieving

Abstract Collaborative results are presented on a new method for the extraction of light filth from bread and donuts. The new method consists of product dispersion by steam bath heating or autoclaving, wet sieving on No. 230 sieve, digestion with HC1, followed by extraction of filth with mineral oil from water. Minimum recovery of spike filth elements was 82%. The new method also proved to be faster than method 36.025 and resulted in cleaner filter papers than 36.026. The proposed method is recommended for adoption 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.

Extraction of Thrips and Other Whole or Equivalent Insects from Frozen Blackberries and Raspberries: Collaborative Study

1981 ◽  
Vol 64 (1) ◽  
pp. 194-195
Author(s):  
Russell G Dent ◽  
◽  
J Boese ◽  
M P Chaput ◽  
D Floyd ◽  
...  
Keyword(s):  
Coefficient Of Variation ◽  
Collaborative Study ◽  
Tween 80 ◽  
Mineral Oil ◽  
Light Mineral

Abstract A method was developed for the extraction of thrips and other whole or equivalent insects from frozen blackberries and raspberries. The method consisted of a thawing and drained weight step, followed by acid maceration. Berries were wet-sieved over a No. 25 sieve nested in a No. 80 sieve. The berry tissue retained on the No. 80 sieve was dehydrated with isopropanol and then treated with chloroform. The chloroform was stripped from the residue with isopropanol. The berry residue was extracted with light mineral oil from a 40% isopropanol-Tween 80- Na4EDTA mixture. The collaborative study was successfully completed with 83.3% average recoveries of thrips and a 19.2% coefficient of variation. The method has been adopted official first action.

Sign in / Sign up

Export Citation Format

Share Document