Document 4JGYXV5b5a3xLpyQ3RrrN0KLj

FILE NAME: DATE: 1975 Oct 7 DOC#: DOCUM ENT DESCRIPTION COSMETIC, TOiLEnavd FRAGRANCE ASBoaxnoimx . ' A i Enclosed is the information which you requested. Please contact CTFA if we can be of further assistance. *r i*# m S?#* V J ! 1133 - 15th 5T.,, N.W., W A S H IN G TO N , Q.C. 20005 * 2 0 2/331-1770 T E L E X 39-2673 I >** m V-.^ r. awr * CTFA Method J 4-1 Issues: 10-7-75 Paget ASBESTfiFORM AMPHIBOLE MINERALS IN COSMETIC TALC Part I: X-ray Diffraction Method Part II: Optical Microscopy and Dispersion-Staining Method Introduction The method which has been adopted for the detection of amphibole minerals in cosmetic talc is the generally accepted method of x-ray diffraction. Methods which appear in the literature for the detection of fibrous amphibole, such as, transmission electron microscopy with selected area diffraction1 and electron microprobe,2 have also been considered since they are capable of a lower level of detection than by x-ray diffraction. However, they have not been adopted since they suffer from the drawbacks, that the amount of material under examination is quite small (less than a microgram) and the time lor analysis, expertise required, and expense of equipment eliminates them as routine methods. The methodology presented is the most practical available, based on current technology The use of Transmission Electron Microscopy with Selected Area Electron Diffraction offers greater sensitivity, but is not presented since it Is unsuitable for normal quality control application. Enrichment or concentration techniques using flotation cells have been tried as a means of improving the detection level; however, all efforts so far have been unsuccessful. Principle The x-ray diffraction method is based upon the principle that when a crystalline material is placed in an x-ray beam, a portion of the x-rays are diffracted by each set of atomic planes within the crystal. The diffracted rays strike a scintillation counter as the sample is scanned through a prescribed angle with the resulting development of peaks corresponding to each interplanar distance (d). A peak with d value in the range of 8.04 to 8.85A6 for a sample talc is strong evidence for the presence of amphibole in that talc. The level of detection of amphibole by this method is 0.5% and above. The variability of-detection is caused by such factors as age and manufacturer of x-ray diffractometers, sample homogeneity, specific amphibole mineral present, morphology of amphibole, particle size, preferred orientation, etc. For these reasons the level of detection should be reported for levels above 0.5%, since below this level the data has been found to be not reproducible. If a statistically significant peak is found of Intensity equal to or greater than that obtained for the 0.5% standard in the d range for amphibole, described above, then the sample must be put through the following confirming scheme: X-ray Diffractometry (-) (+ ) (Acid Leach) Y Stop (Amphibole absent) Optical Microscopy (-) Stop (Amphibole absent) and Dispersion-Staining Color I(+ ) Fibrous Morphology ----(-----)-- ^ Stop (Asbestiform Amphibole absent) I (+) Stop (Asbestiform Amphibole present) COSMETIC, TOILETRY AND FRAGRANCE ASSOCIATION, INC. * 1 1 3 3 Fifteenth Street, N.W., Washington, D.C. 20005 CTFA Method 4-1 issued 10-7-76 Page? Part i: Amphibole Minerals by X-ray Diftractometry Apparatus 1. X-ray diffractometer, employing nickel-filtered copper...K-aipha radiation, horizontal or vertical goniometer with variable scan speed capability, suitable talc pellet sample holder, variable speed recorder, electronic panel including ratemeter and variable attenuation and time constant settings 2. Hydraulic press, capable of attaining a pressure of 15,000 to 24,000 lb calculated on a 3* ram 3. Mortar and pestle or grinding mill (Note 1) 4. Waring Blendor,* or equivalent blender 5. Spex Mixer/MIII,* or equivalent mechanical mixer 6. Sieve, 325-mesh 7. Optical microscope (Note 2) 8. 1W' pellet press Reagents 1. Standard talc sample, containing no detectable amphibole minerals 2. Standard tremolite sample, at least 80% pure Sample of tremolite standard may be obtained by ordering from The Cosmetic Toiletry and Fragrance Associa tion, Inc., 1133 Fifteenth Street, N.W., Washington, D.C. 20005. 3. Denatured ethanol 4. Boric acid Procedure The procedure consists of slow-scanning, under previously determined conditions, a compressed pellet of the sample talc in the 11,0 to 10.02 0(8.85 to 8.04 A) region for the presence of an amphibole peak. There are times when it is difficult to discrimi nate a possible peak for amphibole over the background noise level.i- iRegistered Trademark COSMETIC, TOILETRY AND FRAGRANCE ASSOCIATION, INC. - 1 1 3 3 Fifteenth Street. N.W.. W ashing* D C ?nrm<; 1.V.V.V.V CTFA Method J 4-1 Issued 10-? 75 Page 3 Should the presence of a smell amphibole peak above the background "noise" be In Question, It will be necessary to statistically evaluate the scan. A tmner/scaler is required on the electronic panel of the x-ray diffractometer. In order for a peak to be statistically significant, the peak intensity mus: equal or exceed three standard deviations (3cr) above the average background intensity (N): Where: N + 3c- = minimum peak intensity N = average background count tr = v T T Figure 1. Determine the region of the scan in question: in the Figure 1 scan, a peak appears to be present in the 10.40 to 10.6C 20 region. Slow scan with cumulative pulse counting through the peak region three separate times and average the number of counts. Determine a background count by scanning a region equal to of the 2 region covered by.the peak, immediately before and after the peak. The counting time for each of these background regions will equal the total counting time used for the peak. Count each background region three times. Then average each region and add the two averages to obtain the background count (N). COSMETIC, TOILETRY AND FRAGRANCE ASSOCIATION, INC. * 1133 Fifteenth Street, N.W., Washington, D.C. 2000S Example: in Figure 1. Peak ................ .......... .......... Background Region A ............ .......... Region B .............. .......... Region 10.40 to 10.60 10.30 to 10.40 10.60 to 10.70 Time (sec.) 120 - 60 60 Peak 10.40 to10.60*26 time secs. counts 120 120 120 Average 60,332 59,870 60,105 60,102 Background Region A Region B 10.30 to 10.40*26 10.60 to 10.70*26 time secs, counts time secs, counts 60 28,784 60 28,943 60 28,634 28,787 60 28,506 60 28,368 60 28,204 28,359 CTFA Method J 4-1 issu!: 10-7-76 Paoe 4 N 28,787 + 28,359 57,146 a * V 5 7 .1 4 6 " 239 3cr = 717 N + 3 <r * 57,146 + 717 = 57,863 The actual number of counts obtained for the integrated peak intensity was 60,102; therefore, the ``suspect" peak is statistically present in the scan. COSMETIC, TOILETRY AND FRAGRANCE ASSOCIATION, INC. - 1 1 3 3 Fifteenth Street,N.W., Washington, D.C. 20005 CTFA Method J 4-1 issued. 10-7*76 Pages Standard Preparation Optimal instrument conditions must first be determined with the use of tremolite standards: 1.0%, 0.75% , 0 6% tremolite by weight, prepared ir a standard talc which is free of interfering peaks in the 11.0 to 1G.Oa20 region. Weigh out appropriate amounts of standard talc and tremolite both of which have been ground to pass a 325-m esh sieve. Transferto a Waring Blendor/ Add 100 ml of ethanol to the blender and blend at low speed for 5 minutes. Carefully transfer the contents of the blender, with repeated ethanol washings, into a large beaker. Evaporate the ethanol on a steam bath. Shake the sample in a plastic vial for 5 minutes on a Spex Mixer/MilP to remove clumps and caked sample resulting from the evaporation of ethanol. Determine by microscopy the homogeneity of the prepared standard previous to the x-ray diffraction analysis. Press the homogeneous standard into a 1VC pellet with a backing of boric acid. Transfer 2 ( 0 .2 ) c of standard to the die-holder and evenly distribute on a polished, scratch-free die. Distribute 4 ( 0 .2 ) g of boric acid evenly on the talc layer. Press the mixture into a pellet under conditions suitable for obtaining a smooth planar surface (for example, s pressure of 15,000 to 24,000 lb calculated on a 3" ram has been found to produce suitable pellets). The resulting pellet must have a talc face which is free of flaws: if not, the pellet must be discarded (Note 3). Prepare two acceptable pellets from each standard. 'Registered Trademark COSMETIC, TOILETRY AND FRAGRANCE ASSOCIATION. INC 1 133 Fifteenth Street,N.W., Washington, D.C. 20005 CTFA Method J 4-1 issued 10-7-76 Page 6 Sample Preparation Prepare two pellets from each sample in the manner described for the standard pellets, Make a qualitative scan1 from 4 to 50 *26on one of these pellets to ascertain the presence of amphibole above the 2% level or the presence of mineral impurities having interfering peaks in the 11,0 to 10.0 (8.85 to 8.0 4 A) region of the scan. The presence of such Interference will eliminate use of the x-ray diffraction method for the sample, arid one will have to proceed directly to the microscopical procedure. Instrumentation Instrumental variables are optimized on the 1% standard. Lower standards are then analyzed under the optimum conditions to determine the lower level of detection. Of major importance in obtaining maximum instrument sensitivity are a slow dif fractometer speed combined with compatible recorder speed, and high attenua tion combined with a statistically acceptable time constant on the ratemeter. Under appropriate instrumental conditions the peak obtained for the 0.5% standard should be detectable above background noise as shown in Figure 2. Typical instrumental conditions employed for the Siemens Diffractometer (Mode! No. M386-X-A4), and Counter and Recorder Unit (Type T) are: Radiation: Divergence slit: Goniometer speed: Recorder speed: Attenuation: Time constant: Cu with Kfafilter at 40K V and 24 ma 1 Receiving slit: 0 .2 mm Vio20/minute 300 mm/hour 1 x 103 impulses/second T(s)4 Statistical error of 1.1 % under these conditions Rise Time = 0.18 Attenuator = 20 COSMETIC, TOILETRY AND FRAGRANCE ASSOCIATION, INC. * 1133 Fifteenth Street, N.W.. Washington, D.C. 20005 COSMETIC, TOiLEnavd FRAGRANCE ASBoaxnoimx . ' A i Enclosed is the information which you requested. Please contact CTFA if we can be of further assistance. *r i*# m S?#* V J ! 1133 - 15th 5T.,, N.W., W A S H IN G TO N , Q.C. 20005 * 2 0 2/331-1770 T E L E X 39-2673 I >** m V-.^ r. awr * FILE NAME: DATE: 1975 Oct 7 DOC#: DOCUM ENT DESCRIPTION