IUCr, CPD Quantitative Phase Analysis Round Robin - Call for Expressions of Interest

Lachlan Cranswick lachlan at melbpc.org.au
Wed Feb 5 04:13:22 CST 1997

IUCr, CPD Quantitative Phase Analysis Round Robin - 
     Call for Expressions of Interest

Initiated and Organized by the IUCr Commission on Powder Diffraction

Aims of the Round Robin:
 The round robin will focus on the analysis of powder diffraction data
specifically for the derivation of quantitative phase abundance. While the
study will focus on the use of laboratory X-ray, synchrotron X-ray and
neutron diffraction data, other methods may be used to validate the
diffraction results (e.g. FTIR, normative analysis, etc.). The additional
methods used will be at the discretion of the participant.

General aims
 The general goals of the round robin will include the following:-
  á To document the methods & strategies commonly employed in Quantitative
Phase Analysis (QPA), especially those involving powder diffraction
  á To assess (i)  levels of accuracy & precision, and (ii) lower limits of
  á To identify specific problem areas & develop practical solutions
  á To formulate recommended procedures for QPA using diffraction data
  á To create a standard set of samples for future reference

Specific aims
The round robin will address the following analytical issues:-
 Type of analysis:   diffraction (X-ray /Neutron) vs non-diffraction,
internal std vs external std vs spiking etc, standardless methods
 Sample features:    representivity & homogeneity, particle & crystallite
size, statistics & microabsorption, crystallinity & surface roughness,
preferred orientation, microabsorption & extinction
 Data collection:    type of instrument / geometry, sample preparation, data
range and wavelength
 Data analysis:      integrated intensities vs full-profile, Rietveld vs
data-base of observed patterns, use of constraints and corrections, software
systems & methods, complexity of the pattern - peak overlap

Proposed Samples

The samples used in the study will consist of mixtures of major and minor
components covering a wide range of analytical complexity. All synthetic
samples contain a minor impurity phase (spinel - MgAl2O4) to provide an
ambiguity of chemistry as well as providing estimates of the accuracy and
precision of trace phases.
 ÎSimpleâ system          alpha-Al2O3 + Si + MgAl2O4
 Preferred orientation    Mg(OH)2 + a-Al2O3 + Si + MgAl2O4
 Crystallinity            alpha-Al2O3 + Si + MgAl2O4  + amorphous
 Microabsorption X-ray    alpha-Al2O3 + Fe3O4 + ZrSiO4 + MgAl2O4  
 Microabsorption neutron  alpha-Al2O3 + TiB2 + MgAl2O4
 Complex systems         (i)  Granodiorite  quartz + feldspar (x2) + biotite
                       (ii)  Bauxite ore  gibbsite + hematite + kaolinite + etc
                      (iii)  Pharmaceutical system

Types of analyses
 The involvement of participants in the round robin can vary depending on
the amount of time available to each individual/laboratory.
 However, since the success of the round robin will depend on the number of
results returned, full participation is encouraged.

Possible levels of participation will include the following:-
 Material supplied by CPD        Participant actions
 Diffraction data only	    Participant analyses Îstandardâ data sets
supplied by the CPD and returns details of the analytical procedure plus the
 Prepared samples	    Participant collects own data for analysis from at
least two of the samples supplied by the CPD (Îsimpleâ and Îpreferred
 Unprepared samples	    Samples supplied by the CPD are representative of
bulk, but may need additional preparation. Participant prepares samples for
data collection and analysis.

 Since the purpose of the round robin is to assess the methods of
quantification, and not identification, the identity of each of the
component phases will be supplied. For those participants using Rietveld
based methods for the analysis, full structural information for each of the
phases will also be supplied.
 Participants will be asked to return the results using Îstandardâ reporting
forms. This should minimize the number of errors likely to occur during
transcription of the data. In addition, it is requested that the diffraction
data be returned to the CPD as an ASCII format file for re-analysis with a
Îstandardâ Rietveld code.

The following timeline for the round robin is proposed:-
 Aug / Sept 1996    Final recommendations for mixtures and protocolFormal
approval from CPD
 Aug 96 - Mar 97    Call for expressions of interestSamples sourced &
prepared for distributionCollection of standard dataQuestionnaire sent to
all participants
 June 97            Samples and data distributed to participants
 December 97        Call-in of results
 Jan - June 98      Analysis of results (including late submissions)
 Aug 98             Preliminary results presented at EPDIC-6
 Aug 99             Presentation of final results at Glasgow IUCr Congress

How to participate
Potential participants can register their interest in the round robin by
sending an Email message containing the full contact information to the
address given below. Details should include
 Postal address
 Phone number (including country and area codes)
 FAX number (including country and area codes)
 Email address
Respondents will be sent a questionnaire request information about which if
the samples they wish to analyze plus the amount of sample required (i.e.
are they an X-ray or neutron user).

Operating Team
 Ian Madsen             CSIRO Minerals, Australia
 Rod Hill               CSIRO Minerals, Australia
 Edward Groleau         Eli Lilly & Co, USA
 Lachlan Cranswick      Melbourne, Australia

Advisory Team
 Deane Smith (CPD)      Penn State University, USA
 Jaroslav Fiala         Central Research Institute, Czech Republic

Contact Details for all Correspondence
 Ian Madsen
 CSIRO Minerals,
 PO Box 124,
 Port Melbourne, Victoria  3207,  Australia
 Fax:  +61 3 9646 3223
 E-mail:  qpa.rr at minerals.csiro.au

                  \ | /                 
                  (o o)
     Ian Madsen
     CSIRO Division Of Minerals
     P.O. BOX 124
     Port Melbourne  3207

     Phone  +61 3 9647 0366  direct
            +61 3 9647 0211  switch
     FAX    +61 3 9646 3223
     Email  Ian.Madsen at minerals.csiro.au

   XRD laboratory 'tour' starts at 
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