This questionnaire has been prepared to determine how accredited analytical
laboratories test samples and report results involving the family of crystalline
cristobalite minerals and the family of non-crystalline opal minerals, opal-CT
and opal-C. Please answer the questions as presented and add any supportive
remarks in the space available or on a separate sheet keyed to the question
code. All answers will remain confidential with respect to individual
laboratories. Only cumulative results will be published in any report.
1. Method of analysis for crystalline silica phases
A. How many analyses for crystalline silica do you do in an average year
__1_ 0-10, _13__ 11-100, _19_101-1000, __4_ 1001-10000
B. What type of samples do you analyze
__11_ Air filter ____ Bulk _26_ Both
C. What method of analysis is your primary technique for quantifying crystalline
silica
_22_ X-ray Diffraction _14_ Infrared __3_Chemical
_1__ Optical __2_ Other _Colorimetric__
D. What is the average level of silica in analyzed samples
_23_0-10 wt.% _10__10-50 wt.% ____ 50-100wt.%
E. Indicate the percentage of analyzed samples that are dominantly
____ quartz ____ cristobalite/tridymite ____opal 30 labs do >95% quartz
F. Problems encountered with silica analyses
_12_ Insufficient sample
_9__ Difficult samples
_17_ Interferences among the silica phases
_24_ Interferences from other phases in sample
_7__ Difficulties with identification of silica phases
_13_ Limitations on accuracy in the methods of analysis
_0__ Other
G. Which of the following methods do you employ for the detection of crystalline
silica
_23_ X-ray diffraction _14_ Infrared Analysis
_7__ Chemical (e.g. Phosphoric acid digestion) ____ Differential Thermal
Analysis
_1__ Scanning electron microscopy _1__ Transmission electron microscopy
_6__ Optical microscopy __2_Other __Colorimetric_________________
H. Which of the following methods do you employ for the quantification of
crystalline silica
_22_ X-ray diffraction _14_ Infrared Analysis
__4_ Chemical (e.g. Phosphoric acid digestion) ____ Differential Thermal
Analysis
____ Scanning electron microscopy ____ Transmission electron microscopy
__4_ Optical microscopy __2_Other ___Colorimetric________________
I. General questions
Can you quantify crystalline silica phases at the 0.10% level
_18_ Yes _15_ No
Do you employ preconcentration methods
_11_ Yes _23_ No
What standards do you use for sample and instrument calibration
Sample______AIHA PAT (7)________________Internal Ag (2)__________
____________MinUSil (11)_______________Pre-spiked Stds. (2)_____
____________NIST (17)_______________CanMet (1)_____________
____________NIOSH (7)________________In-House (3+)____________
____________Arkansas (3)_________________________________________
____________Outside suppliers (6)_____________________________________
Instrument______This question was misinterpreted to mean instrument type________
_______not instrument calibration. Calibration standards are listed above.______
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
2. Distinguishing cristobalite and opal
A. Do you recognize cristobalite and opal as distinct silica phases
_7__ Yes _30_ No
(If answer is “No”, go to section 3)
B. Which of the following criteria do you use to distinguish the two phases.
_6__ Value of d-spacing of peak at 22 2 (d = 4.04 - 4.20A)
_5__ Full width at half maximum of peak at 22 2 (FWHM = 0.12 - 3.5)
_3__ Presence of double peak at 22 2 (d = 4.08, 4.20A)
_4__ Asymmetry of peak at 22 2
_4__ Presence of peak at 36 2 (d = 2.50A)
_2__ Recognition of more than two diffraction peaks
_1__ Recognition of more than four diffraction peaks
____ Recognition of more than seven diffraction peaks
____ Tests for presence of water in the phase
_3__ Changes in diffraction pattern with heating
_3__ Confirmation with IR measurements or optical microscopy
____ Confirmation of analysis beyond computer produced values
_1__ TEM
_2__ Other ___Opal removed by H3PO4__________________
3. Reporting of silica results
A. Do you recognize quartz, tridymite, cristobalite and opal as distinct
minerals in reports
_19_ Yes (Except for opal where indicated) _17_ No
B. How do you report final results.
_16_ Percent abundance by individual silica mineral species
_2__ Mass Loading
_12_ Total abundance of all crystalline silica species as one number
____ Do you supply copies of the analytical data to requestors
_1__ Yes _7_ No
_24_ Only if specifically requested
4. Please complete the following information and return in the supplied envelope
Name and address of analytical laboratory
______All but one respondend identified lab____
_______________________________________________
_______________________________________________
_______________________________________________
Name of person responding to questionnaire
_______________________________________________
5. Use this section for further comments on any answer. (Indicate the section by
number and letter.)
___________Does IR. Where XRD required contracts with another AIHA
lab______________________
___________Never have considered opal. Never has been
requested_____________________
___________Only analyzing AIHA PAT
samples___________________________________________
___________Reports respirable dust and respirable
silica_____________________________
___________Employs XRD when quartz is
found__________________________________________
___________Opal determination requires multiple
tests________________________________
___________Several never see opal____Others comment on never seeing
tridymite__________________
___________Some samples have low crystallinity.______________________________________
___________Only reports quartz based on IR___________________________________________
___________Only do in-house
analyses_________________________________________________
| Note: This is historic information. The survey is closed. |
Please return the questionnaire to
Deane K. Smith
1652 Princeton Drive
State College, PA 16803
FAX number is 1-814-238-4069 or 1-814-863-7845
Thank you for your time responding to this important survey
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