Recommendations for reference method for haemoglobinometry in human blood (ICSH standard 1995) and specifications for international haemiglobincyanide standard (4th edition)

Full text

Leaders
Recommendations
for
reference
method
for
haemoglobinometry
in
human
blood
(ICSH
standard
1995)
and
specifications
for
international
haemiglobincyanide
standard
(4th
edition)
International
Council
for
Standardisation
in
Haematology:
Expert
Panel
on
Haemoglobinometry
Introduction
Scientific
symposia
on
haemoglobinometry
were
held
at
the
9th
Congress
of
the
European
Society
of
Haematology,
Lisbon,
1963,'
and
the
10th
Congress
of
the
International
Society
of
Haematology
(ISH),
Stockholm,
1964.2
The
International
Committee
(now
Council)
for
Standardisation
in
Haematology
(ICSH)
made
recommendations
endorsed
by
the
General
As-
sembly
of
ICSH
in
Sydney
on
23
August
1966,3
for
a
reference
method
for
haemoglobinometry
and
for
the
manufacture
and
distribution
of
an
international
reference
preparation.
Further
symposia
were
held
at
the
12th
Congress
of
the
ISH,
New
York,
1968,4
and
at
the
13th
Congress
of
the
ISH,
Munich,
1970.5
The
re-
commendations
were
reissued
in
19786
and
in
1986.7
On
the
basis
of
continuing
experimental
studies,
the
reference
method
and
the
spe-
cifications
for
the
international
standard
have
been
modified.
The
revised
recommendations
are
described
in
this
document.
Members
of
the
expert
panel
on
haemoglobinometry
(1995):
A
Zwart,
Chairman,
Emmen,
The
Netherlands;
0
W
van
Assendelft,
Atlanta,
Georgia,
USA;
B
S
Bull,
Loma
Linda,
California,
USA;
J
M
England,
Watford,
UK;
S
M
Lewis,
London,
UK;
W
G
Zijlstra,
Groningen,
The
Netherlands.
Correspondence
to:
Dr
R
M
Rowan,
Haematology
Department,.
Western
Infirmary,
Dumbarton
Road,
Glasgow
GIl
6NT.
Accepted
for
publication
18
October
1995
Recommendations
for
reference
method
for
haemoglobinometry
in
human
blood
Haemoglobin
is
a
chromoprotein.
On
the
basis
of
the
chemical
structure
of
two
ct
and
two
chains
and
of
four
haem
groups,
it
is
calculated
to
have
a
relative
molecular
mass
of
64
458
(anhydrous).'-
"
The
mass
fraction
of
haemo-
globin
iron
is
therefore
0
003
47.
At
the
Assemblies
in
Kyoto,
Japan,
in
1976
and
Budapest,
Hungary,
in
1984,
ICSH
re-
commended
that
haemoglobin
in
blood
should
be
expressed
as
mass
concentration
in
gil.
In
conformity
with
the
joint
recommendation
for
use
of
the
international
system
of
units
(SI)
in
clinical
laboratory
measurements,
as
agreed
by
ICSH,
the
International
Federation
of
Clinical
Chemistry
(IFCC),
and
the
World
Association
of
Societies
of
Pathology
(WASP),"
substance
concentration
(mmol/l)
may
also
be
used.
In
that
case
the
elementary
entity
(monomer
or
tetramer)
should
be
specified
by
use
of
the
notation
Hb(Fe)
or
Hb(4Fe).
For
measure-
ment
of
the
reference
standard
the
expert
panel
recommends
relating
absorptivity
and
relative
molecular
mass
to
one
haem
group
and
one
quarter
of
the
total
globin
moiety.
PRINCIPLE
Photometric
determination
of
haemiglobin-
cyanide
(HiCN)
(see
note
1)
is
recommended
as
the
reference
method.
If
any
other
method
is
used
in
routine
measurement
(for
example,
photometric
determination
of
oxyhaemoglobin
or
haemiglobinazide;
iron
determination)
it
should
be
adjusted
to
obtain
comparability
with
the
haemiglobincyanide
method.'2
REAGENT
The
haemoglobin
derivatives
occurring
in
blood,
with
the
exception
of
sulphaemoglobin
(see
note
2),
are
converted
into
haemi-
globincyanide
by
the
use
of
an
appropriate
reagent.
The
reagent
must
be
of
such
quality
that
after
dilution
of
the
blood
there
is
no
turbidity
(see
note
3);
the
photometric
de-
termination
must
be
delayed
until
the
reaction
is
completed.
ABSORBANCE
MEASUREMENT
Blood
should
be
diluted
suitably
(for
example,
1:251;
100
gl
Of
blood
+
25
ml
reagent)
13
14
with
reagent,
filtered
with
a
low-binding,
low-release
membrane
filter,
0-2
to
0
25
gm
mean
pore
diameter
(see
note
4)
to
ensure
absence
of
all
particulate
matter,
and
measured
at
540
nm
(see
note
5)
against
an
appropriate
blank
(see
note
6).
The
photometer
must
be
calibrated
as
to
wavelength
and
should
be
checked
frequently
as
to
linearity
(see
note
7)
and
the
absence
of
stray
light;
the
absorbance
scale
should
be
checked
before
each
measurement
series
with-
for
example,
a
certified
glass
filter,
or
a
solution
_7
Clin
Pathol
1996;49:271-274
271
group.bmj.com on July 17, 2011 - Published by jcp.bmj.comDownloaded from

272
of
known
absorbance-for
example,
a
sec-
ondary
haemoglobin
standard.
Even
minor
changes
in
the
set-up
may
cause
significant
deviations
in
calibration.
CALIBRATION
STANDARD
The
haemiglobincyanide
calibration
standard
should
be
an
aqueous
solution
of
haemi-
globincyanide
with
a
concentration
in
the
range
550-850
mg/l
(see
note
8).
It
is
strongly
re-
commended
that
it
be
dispensed
as
a
sterile
solution
in
individual
doses
in
sealed
glass
am-
poules.
The
spectrophotometric
characteristics
must
conform
to
the
specifications
of
the
International
Haemiglobincyanide
Standard:
1.C-54O
1A50
iCN~.
70<A~V
1*59
<AHiCN/AH,CN
<1*63;
AHiCN
<-003
per
cm
lightpath
length;
and
an
absorbance
spectrum
characteristic
for
pure
HiCN
solutions.15
DETERMINATION
OF
HAEMOGLOBIN
CONCENTRATION
Because
HiCN
solutions
strictly
follow
Lambert-Beer's
law,
the
haemoglobin
con-
centration
is
calculated
using
the
relation
be-
tween
absorbance
and
HiCN
concentration
established
in
the
calibration
procedure.
If
this
relation
is
found
to
be
in
conformity
with
t
=
11
0
l.mmol-
.cm
-,
the
haemoglobin
con-
centration
is
calculated
by
means
of
the
fol-
lowing
equation:
40
X
1
X
1000
(1)
540NlXOO
where
AHiCN
=
absorbance
of
the
solution
at
k
=
540
nm;
M
=
relative
molecular
mass
of
haemo-
globin,
derived
from
64
458/49;
F
=
dilution
factor
used
(for
example,
251);
40N
=
mil-
limolar
absorptivity
=
11
01718;
1=lightpath
in
cm;
and
1000=conversion
factor
mg
to
g.
For
a
dilution
(F)
of
251
and
a
lightpath
of
1
000
cm:
c(g/l)
=
367*7
x
A540
(2)
International
haemiglobincyanide
standard
MANUFACTURE
The
international
haemiglobincyanide
stand-
ard
(see
note
9)
is
manufactured
at
three
to
five
year
intervals;
details
of
the
method
are
given
by
Holtz.'9
It
is
made
from
washed
red
cells
from
human
blood
tested
for
the
absence
of
hepatitis
and
HIV
antibodies,
haemolysed
by
toluene,
and
centrifuged-free
from
debris.
The
haemoglobin
is
converted
to
haemi-
globincyanide.
The
final
solution
has
a
haemi-
globincyanide
concentration
of
550-850
mg/l.
It
is
dispensed
in
sealed
10
ml
glass
ampoules
as
a
sterile
solution
after
membrane
filtration
(see
note
10).
EVALUATION
AND
CONTROL
Each
batch
is
tested
in
laboratories
nominated
by
the
ICSH
Board
(see
note
11),
in
accordance
with
the
principles
set
out
below.
The
results
are
analysed
by
a
consultant
who
advises
the
ICSH
Secretariat
on
the
control
of
the
pre-
paration.
CONCENTRATION
The
HiCN
concentration
is
calculated
from
the
results
of
at
least
five
laboratories,
using
the
equation:
c
(g/l)
=
x
16
1
1400
-
1465
x
AHiN
where
A54CN
=
absorbance
of
the
solution
at
k
=
540
nm;
16
114
5
=relative
molecular
mass
of
haemoglobin
monomer,
derived
from
64
458/
49;
110H=ijCN
(millimolar
absorptivity)
(see
note
12);
1
000
=
lightpath
in
cm.
An
equivalent
haemoglobin
concentration
of
the
standard
may
be
calculated
by
multiplying
the
HiCN
concentration
by
the
dilution
factor
(F)
used
in
the
method-for
example,
251
for
100
g1l
blood
plus
25
ml
reagent.
Using
an
appropriate
blank
(see
note
6),
AHCN
is
measured
on
a
spectrophotometer,
the
wavelength
scale
of
which
has
been
calibrated
with
the
aid
of
the
mercury
(or
hydrogen
or
deuterium)
emission
spectrum,
or
holmium
oxide
in
perchloric
acid2021;
on
which
ab-
sorption
checks
have
been
performed
using
calibrated
glass
filters
or
other
means
which
have
been
certified
by
a
standardising
authority
(see
note
13);
and
of
which
the
absence
of
stray
light
has
been
verified.
Its
slit
width
is
chosen
so
that
the
half
intensity
bandwidth
is
less
than
or
equal
to
2
nm.
The
cuvettes
in
which
the
solution
is
measured
are
plan-parallel
with
an
inner
wall
to
wall
distance
of
1
000
cm,
tol-
erance
0
5%
(0-995-1-005).
The
meas-
urements
are
carried
out
at
20-250C.
The
arithmetical
mean
and
standard
error
of
the
results
of
the
laboratories
are
recorded
after
erratic
results,
if
any,
have
been
discarded
in
accordance
with
statistical
practice.22
Ex-
perience
with
this
procedure
has
shown
that
the
confidence
limits
of
the
final
results
are
within
+1%.
PURITY
The
purity
is
controlled
by
(1)
judging
the
shape
of
the
absorbance
curve
between
k
=
450
and
750nm,
lightpath
length
1000
cm
(see
note
14);
(2)
determining
the
quotient
AHiCN/AHiCN,
the
value
of
this
quotient
should
lie
between
1-59
and
1
63;
and
(3)
measuring
at
a
wavelength
between
730
and
770
nm
(near-
infrared)
to
check
turbidity.
This
absorbance
should
be
<
0
003
per
cm
lightpath
length,
using
an
appropriate
blank
(see
note
6).
STABILITY
The
stability
is
checked
by
ICSH
testing
labora-
tories
several
times
each
year.
The
man-
ufacturing
laboratory
repeats
absorbance
meas-
urements
at
more
frequent,
regular
intervals.
The
International
Reference
Standard
is
kept
at
4°C.
It
is
stable
for
more
than
six
years."52'
ICSH
group.bmj.com on July 17, 2011 - Published by jcp.bmj.comDownloaded from

Recommendations
for
reference
method
for
haemoglobinometry
in
human
blood
STERILITY
In
conformity
with
current
practice
of
sterility
control,
the
contents
of
the
ampoules
to
be
tested
are
innoculated
in
aerobic
and
anaerobic
media
and
incubated
at
22
and
37°C
(see
note
15).
LABELLING
The
International
Standard
is
labelled
with
the
batch
number,
the
value
of
its
haemi-
globincyanide
concentration
(mean
and
stand-
ard
error;
see
concentration),
and
an
expiry
date
which
is
considered
well
within
safe
limits
(see
stability).
The
producer
notifies
all
customers
if
con-
tinuing
control
of
stability
indicates
that
a
par-
ticular
batch
is
no
longer
acceptable.
PURPOSE
AND
DISTRIBUTION
The
ICSH
International
Standard
is
used
to
assign
values
to
secondary
HiCN
reference
solutions
or
HiCN
calibration
solutions,
and
as
a
reference
against
which
to
judge
the
purity
of
such
HiCN
solutions.
The
International
Standard
is
made
available
for
reference
use
only
to
national
standards
committees
for
haematological
methods
or
to
official
government
nominated
holders
(see
note
16).
Where
there
is
no
committee
or
official
holder,
it
may
be
distributed
to
in-
dividuals
approved
by
ICSH.
The
national
holder
must
ensure
that
an
opportunity
is
given
to
manufacturers
and
dis-
tributors
to
use
the
International
Haemi-
globincyanide
Standard
as
a
reference
material
if
so
desired,
in
conformity
with
national
re-
quirements.
Information
about
national
committees,
official
holders,
and
other
contact
persons
may
be
obtained
from
the
ICSH
Secretariat,
c/o
Dr
R
M
Rowan,
Haematology
Department,
Western
Infirmary,
Dumbarton
Road,
Glasgow
GIl
6NT.
Notes
(1)
Alternative
terms
for
haemiglobincyanide
are
cyanmethaemoglobin
and
cyanferrihaemo-
globin.
(2)
Sulphaemoglobin
is
converted
to
sulphae-
miglobincyanide.
It
has,
however
been
cal-
culated
that
the
presence
of
1%
sulphaemo-
globin
in
a
blood
specimen
causes
the
total
haemoglobin
concentration
to
be
under-
estimated
by
no
more
than
0.27%24;
in
clinical
practice
sulphaemoglobin
fractions
ex-
ceeding
0-05
are
seldom
encountered.
(3)
A
suitable
reagent,
recommended
by
van
Kampen
and
Zijlstra,25
is
prepared
as
follows:
dissolve
200
mg
K3Fe(CN)6,
50
mg
KCN,
140
mg
KN2PO4
(analytical
grade
chemicals),
and
an
appropriate
amount
of
non-ionic
de-
tergent
in
water
and
dilute
to
1
litre.
The
pH
must
be
7-0-7
4;
the
osmolality
6-7
mmol/
kg.
The
absorbance
at
k
=
540
nm,
measured
against
water
as
blank,
should
be
zero.
If
stored
at
room
temperature
in
a
brown
borosilicate
glass
bottle,
the
solution
keeps
for
at
least
two
months
at
approximately
20°C.
K3Fe(CN)6
is
destroyed
by
freezing;
this
decomposition
can
be
prevented
by
the
addition
of
ethanol,
meth-
anol,
ethylene
glycol
(20
ml/l),
or
glycerol
(5
ml/1).26
Examples
of
suitable
non-ionic
de-
tergents
are
Nonidet
P40
(Shell
International)
1
ml/l
and
Triton
X-1
00
(Rohm
and
Haas)
1
ml/
1.
They
are
available
in
general
from
labor-
atory
chemical
suppliers.
The
reagent
has
a
conversion
time
of
three
to
five
minutes
in
contrast
to
the
original
or
modified
Drabkin's
reagent
with
a
conversion
time
of
15
minutes
or
more.
Because
of
the
longer
conversion
time,
as
well
as
the
greater
incidence
of
turbidity,
these
other
reagents
are
not
recommended.
A
modified
van
Kampen-Zijlstra
reagent
has
been
described27
for
suppression
of
turbidity
in
samples
from
patients
with
a
high
white
blood
cell
count
or
a
high
y
globulin
concentration.
The
conversion
time
of
carboxyhaemoglobin
to
HiCN
is
considerably
longer,
up
to
30
min-
utes.'5
(4)
Examples
of
low-binding,
low-release
filters
are
(0.22
gm)
polyvinylidene
difluoride
Millex-
GV
(Millipore)
and
(0
20
,m)
polypropylene
Paradisc
25
PP
(Whatman).
(B.
Houwen,
Loma
Linda
University
Medical
School:
per-
sonal
communication).
(5)
High
resolution
spectrophotometry
by
the
panel
and
by
the
US
National
Institute
of
Standards
and
Technology
has
shown
the
wavelength
of
maximal
absorbance
to
be
541-05+0-11
nm,
and
an
absorbance
mini-
mum
to
be
at
503-47+0-14nm.
When
meas-
uring
at
540
nm,
the
absorbance
difference
with
respect
to
541
05
nm
is
0
1
%.
(6)
The
reagent
does
not
absorb
light
(see
note
3).
Some
modem
spectrophotometers
have,
however,
been
identified
that
show
apparent
light
absorption
between
500
and
600
nm
by
the
reagent.
It
is
not
clear
whether
this
apparent
absorption
is
caused
by
stray
light
or
by
internal
cuvette
reflections.
The
laboratory
should
thus
verify
that,
for
a
particular
instrument-cuvette
combination,
the
reagent
does
not
absorb
light.
If
apparent
light
absorption
is
found,
a
reagent
blank
should
be
used
when
measuring.
(7)
Linearity
may
be
verified
using
a
procedure
such
as
that
described
by
Eilers
and
Crocker98
with
a
sterile,
membrane-filtered
(at
pore
size
0-2-0
25
,m)
haemiglobincyanide
cal-
ibration
standard.
With
present-day
spec-
trophotometers,
calibration
may
resolve
itself
into
verifying
that
the
instrument
yields
an
accurate
value
for
AHCN
of
a
secondary
haemi-
globincyanide
standard.
Slight
deviations
from
the
expected
AHiCN
value
may
be
used
to
correct
measurement
results.
(8)
Solutions
of
lower
concentration
are
not
reliable.
(9)
The
standards
were
originally
designated
by
the
World
Health
Organisation
(WHO)29
as
International
Haemiglobincyanide
Reference
Preparations.
They
are
now
designated
Inter-
national
Haemiglobincyanide
Standards.
(10)
It
was
agreed
that,
whereas
the
Inter-
national
Reference
Preparation
would
be
aque-
ous,
national
boards
might
provide
glycerinated
solutions
if
preferred.
273
group.bmj.com on July 17, 2011 - Published by jcp.bmj.comDownloaded from

274
(11)
At
present
these
laboratories
are
Atlanta
(USA),
Scientific
Resources
Program,
NCID,
Centers
for
Disease
Control
and
Prevention
(O
W
van
Assendelft);
Emmen
(The
Neth-
erlands),
Scheperziekenhuis
(A
Zwart);
Gai-
thersburg
(USA),
Laboratory
of
the
College
of
American
Pathologists,
National
Institute
of
Standards
and
Technology
(M
Welch);
Gron-
ingen
(The
Netherlands),
University
of
Gron-
ingen,
Faculty
of
Medicine
(W
G
Zijlstra);
Loma
Linda
(USA),
Loma
Linda
University
Medical
School
(B
Houwen);
London
(UK),
Royal
Postgraduate
Medical
School
(S
M
Lewis);
Rome
(Italy),
Instituto
Superiore
di
Sanita
(A
M
Salvati).
(12)
See
van
Kampen
and
Zijlstra'5,
Zijlstra
and
van
Kampen'7,
and
van
Assendelft
and
Zijlstra.
(13)
See
Menzies30
and
National
Bureau
of
Standards.3'
(14)
See
van
Kampen
et
al'3
and
van
Kampen
and
Zijlstra.'5
(15)
Always
checked
by
the
producer.
(16)
The
distribution
is
sponsored
by
the
WHO.29
1
ESH.
Haemoglobinometry:
erythrocytometric
methods
and
their
standardization.
Bibl
Haematol
1964;18:59-85.
2
ISH.
Haemoglobinometry
and
molecular
weight
of
haemo-
globin.
Standardization,
documentation
and
normal
val-
ues
in
haematology.
Bibl
Haematol
1965;21:25-102.
3
ICSH.
Recommendations
for
haemoglobinometry
in
human
blood.
BrJrHaematol
1967;13(Suppl):71-6.
4
Astaldi
G,
Sirtori
C,
Vanzetti
G
(eds).
Standardization
in
haematology.
Milan:
Fondazione
Carlo
Erba,
1969.
5
Izak
G,
Lewis
SM
(eds).
Modem
concepts
in
haematology.
New
York:
Academic
Press,
1972.
6
ICSH.
Recommendations
for
reference
method
for
haemo-
globinometry
in
human
blood
(ICSH
Standard
EP6/2:
1977)
and
specification
for
international
haemi-
globincyanide
reference
preparation
(ICSH
Standard
EP6/3:1977).
I
Clin
Pathol
1978;31:139-43.
7
ICSH.
Recommendations
for
reference
method
for
haemo-
globinometry
in
human
blood
(ICSH
standard
1986)
and
specifications
for
international
haemiglobincyanide
reference
preparation
(3rd
edition).
Clin
Lab
Haematol
1987;9:73-9.
8
Braunitzer
G,
Gehring-Muller
R,
Hilschmann
N,
Hilse
K,
Hobom
G,
RudloffV,
et
al.
Die
Konstitution
des
normalen
adulten
Humanhamoglobins.
Hoppe-Seylers
Zeitschrnft
fiir
physiologische
Chemie
1961;325:283-6.
9
Braunitzer
G.
The
molecular
weight
of
haemoglobin.
Bibl
Haematol
1964;18:59-60.
10
Hill
RJ,
Konigsberg
W,
Guidotti
G,
Craig
LC.
The
structure
of
human
hemoglobin.
Parts
1-5.
Biol
Chem
1962;237:
1549-54;2184-95;2547-61;3151-6;3157-62.
11
ICSH,
IFCC,
WASP.
Recommendations
for
use
of
SI
in
clinical
laboratory
measurements.
BrJtHaematol
1972;23:
787;
Z
Klin
Chem
Klin
Biochem
1973;11:93.
ICSH
12
Kwant
G,
Oeseburg
B,
Zwart
A,
Zijlstra
WG.
Calibration
of
a
practical
haemoglobinometer.
Clin
Lab
Haematol
1987;9:
387-93.
13
van
Kampen
EJ,
Zijlstra
WG,
van
Assendelft
OW,
Reinkingh
WH.
Determination
of
hemoglobin
and
its
derivatives.
Adv
Clin
Chem
1965;8:141-87.
14
van
Assendelft
OW.
Spectrophotometry
of
haemoglobin
de-
rivatives.
Assen:
van
Gorcum,
1970;
Springfield,
Illinois:
Charles
C
Thomas,
1970.
15
van
Kampen
EJ,
Zijlstra
WG.
Spectrophotometry
of
hemo-
globin
and
hemoglobin
derivatives.
Adv
Clin
Chem
1983;23:
199-257.
16
Zijlstra
WG,
Buursma
A,
Zwart
A.
Molar
absorptivities
of
human
hemoglobin
in
the
visible
spectral
range.
J
Appl
Physiol
1983;54:
1287-91.
17
Zijlstra
WG,
van
Kampen
EJ.
Standardization
of
hemo-
globinometry.
I.
The
extinction
coefficient
of
hemi-
globincyanide
at
k
=
540
mp:
£H4CN
Clin
Chim
Acta
1960;
5:719-26.
18
van
Assendelft
OW,
Zijlstra
WG.
Extinction
coefficients
for
use
in
equations
for
the
spectrophotometric
analysis
of
haemoglobin
mixtures.
Anal
Biochem
1975;69:43-8.
19
Holtz
AH.
Some
experience
with
a
cyanhemiglobin
solution.
Bibl
Haematol
1965;21:75-8.
20
Jansen
AP,
van
Kampen
EJ,
Steigstra
H,
van
der
Ploeg
PHW,
Zwart
A.
Simultaneous
spectrophotometric
calibration
of
wavelength
and
absorbance
in
an
interlaboratory
survey
using
holmium
oxide
(Ho203)
in
perchloric
acid
as
ref-
erence,
compared
with
p-nitrophenol
and
cobaltous
sulfate
solutions
(1978-1984).
Jf
Clin
Chem
Clin
Biochem
1986;
24:141-6.
21
Weidner
VR,
Mavrodineanu
R,
Mielenz
KD,
Velapoldi
RA,
Eckerle
KL,
Adams
B.
Spectral
transmittance
char-
acteristics
of
holmium
oxide
in
perchloric
acid
solution.
Jtournal
of
Research
of
the
National
Bureau
of
Standards
1985;90:115-25.
22
Dixon
WJ.
Processing
data
for
outliers.
Biometrics
1953;9:
74-89.
23
van
Assendelft
OW,
Buursma
A,
Holtz
AH,
van
Kampen
EJ,
Zijlstra
WG.
Quality
control
in
haemoglobinometry
with
special
reference
to
the
stability
of
haemi-
globincyanide
reference
solutions.
Clin
Chim
Acta
1976;
70:161-9.
24
Dijkhuizen
P,
Buursma
A,
Gerding
AM,
Zijlstra
WG.
Sulfhaemoglobin.
Absorption
spectrum,
millimolar
ex-
tinction
coefficient
at
k=
620
nm,
and
interference
with
the
determination
of
haemoglobin
and
of
haemi-
globincyanide.
Clin
Chim
Acta
1977;78:479-87.
25
van
Kampen
EJ,
Zijlstra
WG.
Standardization
of
hemo-
globinometry.
II.
The
hemiglobincyanide
method.
Clin
Chim
Acta
1961;6:538-44.
26
Zweens
J,
Frankena
H,
Zijlstra
WG.
Decomposition
on
freezing
of
reagents
used
in
the
ICSH-recommended
method
for
the
determination
of
total
haemoglobin
in
blood,
its
nature,
cause,
and
prevention.
Clin
Chim
Acta
1979;91:337-52.
27
Matsubara
T,
Okuzono
H,
Senba
U.
A
modification
of
van
Kampen-Zijlstra's
reagent
for
the
hemiglobincyanide
method.
Clin
Chim
Acta
1979;93:163-4.
28
Eilers
R,
Crocker
C.
The
value
of
Ringbom
curves
in
hemoglobinometry.
In:
Izak
G,
Lewis
SM,
eds.
Modem
concepts
in
hematology.
New
York:
Academic
Press,
1972:
58-65.
29
World
Health
Organization.
WHO
Expert
Committee
on
Biological
Standardization.
20th
Report.
World
Health
Organ
Tech
Rep
Ser
1968;384:12-
13;86-7.
30
Menzies
AC.
Report
on
calibration
of
wavelength
and
pho-
tometric
scales
of
non-recording
spectrophotometers.
Pure
Appl
Chem
1960;1:
147-62.
31
National
Bureau
of
Standards.
Standard
reference
materials
No.
51:
Glass
filters
as
a
standard
reference
material
for
spectrophotometry.
NBS
Special
Publication
260.
Wash-
ington
DC:
Govemment
Printing
Office,
1975.
group.bmj.com on July 17, 2011 - Published by jcp.bmj.comDownloaded from

doi: 10.1136/jcp.49.4.271
1996 49: 271-274J Clin Pathol
A Zwart, O W van Assendelft, B S Bull, et al.
(4th edition).
standardinternational haemiglobinocyanide
standard 1995) and specifications for
haemoglobinometry in human blood (ICSH
Recommendations for reference method for
http://jcp.bmj.com/content/49/4/271.citation
Updated information and services can be found at:
These include:
References
http://jcp.bmj.com/content/49/4/271.citation#related-urls
Article cited in:
service
Email alerting
the box at the top right corner of the online article.
Receive free email alerts when new articles cite this article. Sign up in
Notes
http://group.bmj.com/group/rights-licensing/permissions
To request permissions go to:
http://journals.bmj.com/cgi/reprintform
To order reprints go to:
http://group.bmj.com/subscribe/
To subscribe to BMJ go to:
group.bmj.com on July 17, 2011 - Published by jcp.bmj.comDownloaded from