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Institute for Reference Materials and Measurements (IRMM)Geel, Belgium
http://www.irmm.jrc.behttp://www.jrc.cec.eu.int
Workshop on water in food - 30th of March 2004 - Influence of water on the property values of CRMs - Seyhan Yazgan - 1
Influence of Water on the Property Values of Certified Reference Materials
Seyhan Yazgan, Alexander Bernreuther, Franz Ulberth, Heinz-Dieter Isengard
Workshop on water in food - 30th of March 2004 - Influence of water on the property values of CRMs - Seyhan Yazgan - 2
Content
• Introduction
• Certified Reference Materials (CRMs)
• Influence of water on the assigned value
• Comparison of different methods for water/moisture determination
• TG-MS analysis
• Kinetic analysis
• Conclusions
Workshop on water in food - 30th of March 2004 - Influence of water on the property values of CRMs - Seyhan Yazgan - 3
Certified Reference Materials (CRMs)BCR-517 FULL FAT SOYA (dietary fibre)BCR-518 BRAN BREAKFAST CEREAL (dietary fibre)BCR-519 ANHYDROUS BUTTER FAT (triglycerides)BCR-522 BOVINE BLOOD LYSATE (haemiglobincyanide)BCR-524 INDUSTRIAL SOIL (PAH's)BCR-528 BACILLUS CEREUS (number of colony forming particles)BCR-529 INDUSTRIAL SANDY SOIL (PCDD's, PCDF's)BCR-530 INDUSTRIAL CLAY SOIL (PCDD's, PCDF's)BCR-532 (RM) UNSPIKED MILK POWDER (PCDD, PCDF blank)BCR-533 (RM) SPIKED MILK POWDER (PCDD's, PCDF's, low level)BCR-535 FRESHWATER HARBOUR SEDIMENT (PAH's)BCR-536 FRESHWATER HARBOUR SEDIMENT (PCB's)BCR-537 PLASTIC FILM (OVERALL MIGRATION IN OLIVE OIL (film A)BCR-542 MUSSEL (dc-saxitoxin)BCR-544 LYOPHYLISED CHROMIUM SOLUTION (Cr III, Cr VI)BCR-545 WELDING DUST LOADED ON FILTER (Cr VI, Cr)BCR-547 ACETALDEHYDE-2,4-DINITROPHENYLHYDRAZONE (purity)BCR-549 ACETONE-2,4-DINITROPHENYLHYDRAZONE (purity)BCR-551-2 2,4-DINITROPHENYLHYDRAZONES in ACETONITRILEBCR-555 CHLORINATED HYDROCARBONS ON TENAXBCR-562 AROMATIC HYDROCARBONS ON CHARCOALBCR-563 COMMON WHEAT FLOUR (properties)BCR-564 SiO2/Si (10,50,120 nm)BCR-577 HUMAN SERUM (17 ß-ESTRADIOL, medium level)BCR-578 HUMAN SERUM (17 ß-ESTRADIOL, high level)BCR-579 COASTAL SEAWATER (Hg)BCR-580 ESTUARINE SEDIMENT (Hg, methylmercury)BCR-642 HUMAN URINE (As, Cd, Cr, Co and 1-hydroxypyrene)BCR-645 ARTIFICIAL FOODSTUFF (Free sugars and starch/gluchose)BCR-647 HUMAN ADENOSINE DEAMINASE (ADA 1)BCR-648-9 BOVINE LIVERBCR-651 BEER (EtOH, low level)
BCR-605 URBAN DUST (trimethyllead)BCR-607 MILK POWDER (PCDD's, PCDF's)BCR-609 GROUND WATER (trace elements, low level)BCR-626 ARSENOBETAINE STANDARD SOLUTIONBCR-627 TUNA FISH TISSUE (As species)BCR-628 ABNORMAL REFERENCE PLASMA-2 for prothrombin timeBCR-629 EUROPEAN REFERENCE PLASMA for Factor VIIIBCR-653 WINE (EtOH, low level)BCR-656 ABSOLUTE ALCOHOLBCR-657 GLUCOSEBCR-658 SYNTHETIC WINEBCR-715 WASTEWATER (INDUSTRIAL EFFLUENT) (trace elements)BCR-716 MAIZE (very low level ZON)BCR-717 MAIZE (low level ZON)BCR-718 CANNED FRESH HERRINGBCR-719 CANNED FRESH CHUBBCR-720 FLOUNDER BILE (PAHs)BCR-721 PLAICE BILE (PAHs)IRMM-410S-0 GENETICALLY MODIFIED SOYA BEANS (0 % RR)IRMM-411R-0 GENETICALLY MODIFIED Bt-176 MAIZE (0 %)IRMM-413-1 GENETICALLY MODIFIED MON810 MAIZE (0.1 %)IRMM-440 RESIN-BONDED FIBRE BOARD (thermal conductivity)IRMM-441 n-HEPTANE (purity)IRMM-442 ISOOCTANE (purity)IRMM-443-1 EUROSOIL (adsorption coefficients and pH)IRMM-444 Pork fat (PCB blank)IRMM-445 Pork fat (very low PCB level)IRMM-446 Pork fat (low PCB level)IRMM/IFCC-451 CORTISOL REFERENCE SERUM PANELIRMM-502A 237NpO2 (0.5 mm spheres)IRMM-534C Al-2.0 % Sc (1.0 mm wire)
BCR-517 FULL FAT SOYA (dietary fibre)BCR-518 BRAN BREAKFAST CEREAL (dietary fibre)BCR-519 ANHYDROUS BUTTER FAT (triglycerides)BCR-522 BOVINE BLOOD LYSATE (haemiglobincyanide)BCR-524 INDUSTRIAL SOIL (PAH's)BCR-528 BACILLUS CEREUS (number of colony forming particles)BCR-529 INDUSTRIAL SANDY SOIL (PCDD's, PCDF's)BCR-530 INDUSTRIAL CLAY SOIL (PCDD's, PCDF's)BCR-532 (RM) UNSPIKED MILK POWDER (PCDD, PCDF blank)BCR-533 (RM) SPIKED MILK POWDER (PCDD's, PCDF's, low level)BCR-535 FRESHWATER HARBOUR SEDIMENT (PAH's)BCR-536 FRESHWATER HARBOUR SEDIMENT (PCB's)BCR-537 PLASTIC FILM (OVERALL MIGRATION IN OLIVE OIL (film A)BCR-542 MUSSEL (dc-saxitoxin)BCR-544 LYOPHYLISED CHROMIUM SOLUTION (Cr III, Cr VI)BCR-545 WELDING DUST LOADED ON FILTER (Cr VI, Cr)BCR-547 ACETALDEHYDE-2,4-DINITROPHENYLHYDRAZONE (purity)BCR-549 ACETONE-2,4-DINITROPHENYLHYDRAZONE (purity)BCR-551-2 2,4-DINITROPHENYLHYDRAZONES in ACETONITRILEBCR-555 CHLORINATED HYDROCARBONS ON TENAXBCR-562 AROMATIC HYDROCARBONS ON CHARCOALBCR-563 COMMON WHEAT FLOUR (properties)BCR-564 SiO2/Si (10,50,120 nm)BCR-577 HUMAN SERUM (17 ß-ESTRADIOL, medium level)BCR-578 HUMAN SERUM (17 ß-ESTRADIOL, high level)BCR-579 COASTAL SEAWATER (Hg)BCR-580 ESTUARINE SEDIMENT (Hg, methylmercury)BCR-642 HUMAN URINE (As, Cd, Cr, Co and 1-hydroxypyrene)BCR-645 ARTIFICIAL FOODSTUFF (Free sugars and starch/gluchose)BCR-647 HUMAN ADENOSINE DEAMINASE (ADA 1)BCR-648-9 BOVINE LIVERBCR-651 BEER (EtOH, low level)
BCR-605 URBAN DUST (trimethyllead)BCR-607 MILK POWDER (PCDD's, PCDF's)BCR-609 GROUND WATER (trace elements, low level)BCR-626 ARSENOBETAINE STANDARD SOLUTIONBCR-627 TUNA FISH TISSUE (As species)BCR-628 ABNORMAL REFERENCE PLASMA-2 for prothrombin timeBCR-629 EUROPEAN REFERENCE PLASMA for Factor VIIIBCR-653 WINE (EtOH, low level)BCR-656 ABSOLUTE ALCOHOLBCR-657 GLUCOSEBCR-658 SYNTHETIC WINEBCR-715 WASTEWATER (INDUSTRIAL EFFLUENT) (trace elements)BCR-716 MAIZE (very low level ZON)BCR-717 MAIZE (low level ZON)BCR-718 CANNED FRESH HERRINGBCR-719 CANNED FRESH CHUBBCR-720 FLOUNDER BILE (PAHs)BCR-721 PLAICE BILE (PAHs)IRMM-410S-0 GENETICALLY MODIFIED SOYA BEANS (0 % RR)IRMM-411R-0 GENETICALLY MODIFIED Bt-176 MAIZE (0 %)IRMM-413-1 GENETICALLY MODIFIED MON810 MAIZE (0.1 %)IRMM-440 RESIN-BONDED FIBRE BOARD (thermal conductivity)IRMM-441 n-HEPTANE (purity)IRMM-442 ISOOCTANE (purity)IRMM-443-1 EUROSOIL (adsorption coefficients and pH)IRMM-444 Pork fat (PCB blank)IRMM-445 Pork fat (very low PCB level)IRMM-446 Pork fat (low PCB level)IRMM/IFCC-451 CORTISOL REFERENCE SERUM PANELIRMM-502A 237NpO2 (0.5 mm spheres)IRMM-534C Al-2.0 % Sc (1.0 mm wire)
• Calibration • Method validation• Quality control
CRMs are used for
Workshop on water in food - 30th of March 2004 - Influence of water on the property values of CRMs - Seyhan Yazgan - 4
Interlaboratory comparison
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0
wat
er c
on
ten
t
%
-100
-80
-60
-40
-20
0
20
40
60
80
100
Dev
iati
on
fro
m t
he
KF
-tit
rati
on
val
ue
in %
below 80 deg C 80-85 deg C 100-102 deg C 103-105 deg C 106-120 deg C 130 deg C
Results for water content on the non-equilibrated CTS as reported by IMEP-19 participants using drying-oven method according to applied drying temperature
IMEP- 19: Trace elements in Rice water content (Karl Fischer Titration) : 4.53 ± 0.22 % [U =k ·u c (k =1)]
1 valueabove 100%
Workshop on water in food - 30th of March 2004 - Influence of water on the property values of CRMs - Seyhan Yazgan - 5
1.52
1.54
1.56
1.58
1.60
1.62
1.64
1.66
1.68
1.70
1.72
0.53 1.53 2.53 3.53 4.53 5.53 6.53 7.53
water content in %
corr
ecte
d va
lue
in m
g/kg
Example for the influence of the water content on the assigned value
Analyte: CadmiumMaterial: rice flour (IRMM-804)
assigned value:1.618 mg/kg ± 0.028 mg/kg
1.5851.601
1.671
1.653
1.635
1.569
Workshop on water in food - 30th of March 2004 - Influence of water on the property values of CRMs - Seyhan Yazgan - 6
Comparison drying oven - KFT
Analysed CRMs: • BCR-380R whole milk powder• BCR-685 skimmed milk powder• IRMM-804 rice flour • BCR-679 cabbage powder • BCR-515 dried carrot • BCR-431 Brussels sprouts • BCR-485 mixed vegetables • BCR-516 dried apple
Methods:• Volumetric Karl-Fischer titration• Drying oven(102 °C ± 2 °C, for 2 h [IDF 26 A: 1993 for milk powder])
Workshop on water in food - 30th of March 2004 - Influence of water on the property values of CRMs - Seyhan Yazgan - 7
Results
02468
10121416
BCR-
380R
whol
e m
ilkpo
wder
BCR-
685
skim
med
milk
powd
er
IRM
M-8
04ric
e flo
ur
BCR-
679
cabb
age
powd
er
BCR-
516
drie
d ap
ple
BCR-
515
drie
d ca
rrot
BCR-
485
mix
edve
geta
bles
BCR-
431
Brus
sels
spro
utsm
oist
ure/
wate
r con
tent
in %
drying oven 120 min at 102 °C KFT (minimum extraction time: 3 min at 40 °C)
Workshop on water in food - 30th of March 2004 - Influence of water on the property values of CRMs - Seyhan Yazgan - 8
TG - MS
Workshop on water in food - 30th of March 2004 - Influence of water on the property values of CRMs - Seyhan Yazgan - 9
BCR-685 skimmed milk powder
H2O
temperature
mass loss
Workshop on water in food - 30th of March 2004 - Influence of water on the property values of CRMs - Seyhan Yazgan - 10
BCR-679 cabbage powder
H2O
temperature
mass loss
CO2
Workshop on water in food - 30th of March 2004 - Influence of water on the property values of CRMs - Seyhan Yazgan - 11
Whole milk powder (BCR-380R) over saturated solutions
TG Analysis
• Temperature scanning rate: 10 °C/min• 20 to 180 °C
potassium sulfate sodium chloride magnesium nitrate lithium chloride molecular sievetheor. aw 0.936 0.753 0.529 0.113 --
Sample preparation: 7 days in desiccators over different saturated salt solutions
Water content in %K2SO4 NaCl Mg(NO3)2 LiCl molecular sieve from bottle
n 6 6 6 6 6 6mean 14.60 8.41 5.26 3.20 0.80 3.37
SD 0.24 0.11 0.14 0.38 0.10 0.05RSD in % 1.65 1.25 2.65 11.90 12.26 1.44
Workshop on water in food - 30th of March 2004 - Influence of water on the property values of CRMs - Seyhan Yazgan - 12
TG - BCR-380 whole milk powder
-16
-14
-12
-10
-8
-6
-4
-2
0
20 15 30 45 60 75 90 105 120 135 150 165 180 195
temperature in °C
wei
gh
t lo
ss in
%14.60 8.41 5.26 3.20 0.80 3.37water content in %
free water
crystal water
decomposition
Temperature scanning rate: 10 °C/min
Workshop on water in food - 30th of March 2004 - Influence of water on the property values of CRMs - Seyhan Yazgan - 13
DTG - BCR-380 whole milk powder
-3.5
-3
-2.5
-2
-1.5
-1
-0.5
0
0.5
15 35 55 75 95 115 135 155 175 195
temperature in °C
DT
G in
°C
/min
14.60 8.41 5.26 3.20 0.80 3.37water content in %:
Temperature scanning rate: 10 °C/min
free water
crystal water
decomposition
DTG
in %
/min
Workshop on water in food - 30th of March 2004 - Influence of water on the property values of CRMs - Seyhan Yazgan - 14
Kinetic analysis
Analysed food components:
• Pectin, esterification degree (ED): 94 %• Pectin, esterification degree (ED): 65 %• Pectin, esterification degree (ED): 25 %• Starch, 73 % amylopectin (AP), 27 % amylose• Starch, 100 % amylopectin (AP)• Gelatine 75 Bloom• Gelatine 225 Bloom• Cellulose microgranular• Cellulose fibrous medium• Cellulose fibrous long• Casein
• Before- mentioned CRMs
Workshop on water in food - 30th of March 2004 - Influence of water on the property values of CRMs - Seyhan Yazgan - 15
Moisture sorption analyser
Workshop on water in food - 30th of March 2004 - Influence of water on the property values of CRMs - Seyhan Yazgan - 16
• Relative humidity (RH) step 15 % to 80 %• Constant temperature of 25 °C
Workshop on water in food - 30th of March 2004 - Influence of water on the property values of CRMs - Seyhan Yazgan - 17
0
5
10
15
20
25
0 20 40 60 80 100 120 140 160time
wei
ght i
n %
skimmed milk powder
gelatine 75 Bloom
casein
starch
pectin 25 % ED
rice flour
whole milk powder
pectin 65 % ED
pectin 94 % ED
cellulose
gelatine 225 Bloom
time in s
wei
ght g
ain
in %
Water uptake kinetic of different food models and CRMs
Humidity step: 15 % to 80 %Temperature: 25 °C
Workshop on water in food - 30th of March 2004 - Influence of water on the property values of CRMs - Seyhan Yazgan - 18
))exp(1()( BtAtm ⋅−−⋅=
stretched-exponential model
Pectin, esterification degree: 25 %-5
0
5
10
15
20
25
30
0 20 40 60 80 100 120 140
time
wat
er u
pta
ke in
%
water uptake exponential model
Workshop on water in food - 30th of March 2004 - Influence of water on the property values of CRMs - Seyhan Yazgan - 19
Factor A
0
5
10
15
20
25
30
35
Pectin
94%
Pectin
65%
Pectin
25%
Starch
73% AP
Starch
100%
AP
Gelatin
e 75B
loom
Gelatin
e 225
Bloom
Cellulos
e micr
ogran
ular
Cellulos
e fibr
ous m
edium
Cellulos
e fibr
ous lo
ng Casein
IRMM-804 r
ice flo
ur
BCR-685 s
kimmed
milk
powde
r
BCR-380R
whole m
ilk po
wder
BCR-516 d
ried a
pple
BCR-515 D
ried C
arrot
BCR-431 B
russe
ls spro
uts
BCR-485 M
ixed v
egeta
bles
BCR-679 c
abba
ge po
wder
Workshop on water in food - 30th of March 2004 - Influence of water on the property values of CRMs - Seyhan Yazgan - 20
Factor B
0.00
0.02
0.04
0.06
0.08
0.10
0.12
0.14
0.16
0.18
0.20
Pectin
94%
Pectin
65%
Pectin
25%
Starch
73% AP
Starch
100%
AP
Gelatin
e 75B
loom
Gelatin
e 225
Bloom
Cellulos
e micr
ogran
ular
Cellulos
e fibr
ous m
edium
Cellulos
e fibr
ous lo
ng Casein
IRMM-804 r
ice flo
ur
BCR-685 s
kimmed
milk
powde
r
BCR-380R
whole m
ilk po
wder
BCR-516 d
ried a
pple
BCR-515 D
ried C
arrot
BCR-431 B
russe
ls spro
uts
BCR-485 M
ixed v
egeta
bles
BCR-679 c
abba
ge po
wder
Workshop on water in food - 30th of March 2004 - Influence of water on the property values of CRMs - Seyhan Yazgan - 21
-5
0
5
10
15
20
25
0 20 40 60 80 100 120 140
time
wat
eru
pta
ke in
%
Pectin, ED: 94% Pectin, ED: 65% Pectin, ED: 25%
time in min
Workshop on water in food - 30th of March 2004 - Influence of water on the property values of CRMs - Seyhan Yazgan - 22
Pectin
Workshop on water in food - 30th of March 2004 - Influence of water on the property values of CRMs - Seyhan Yazgan - 23
0
1
2
3
4
5
6
7
0 20 40 60 80 100 120 140
time
wat
er u
ptak
e in
%
cellulose microgranular cellulose fibrous medium cellulose fibrous long
time in min
Workshop on water in food - 30th of March 2004 - Influence of water on the property values of CRMs - Seyhan Yazgan - 24
Conclusions
For CRM user:• be aware of hygroscopicity of CRMs (i.e. avoid long exposure to environmental humidity)• perform water content determination accurately (chose the rightmethod)For CRM producer:• check the homogeneity (e.g. online NIR-spectrometer)• water content is a source of uncertainty (in some cases the
major source)
• Water uptake kinetics and water uptake capacity depend on the composition of the sample
• High temperatures (oven method) may cause decomposition of the material → higher moisture contents
Workshop on water in food - 30th of March 2004 - Influence of water on the property values of CRMs - Seyhan Yazgan - 25