Arsenic and Antimony:
Poisons or Not?
Element Speciation Analysis has the Answer
Helle Rüsz Hansen
University of Crete, Department of Chemistry
Environmental Chemical Processes Laboratory
CASE STUDY 1:
Consumption of As in seaweed
CASE STUDY 2:
Sb in juices contained in PET bottles
The poison Arsenic
HIGH ACUTE TOXICITY: with symptoms as problems
swallowing, vomiting, diarrhoea, stomach cramps etc.
HIGH CHRONIC TOXICITY: includes cancer,
diabetes, thickening of the skin, liver disease and
problems with the digestive system
Skin cancers
Arsenic-Laced Well Water Poisoning Bangladeshis
Pallava Bagla in New Delhi
for National Geographic News
June 5, 2003
Possibly the largest mass poisoning in history
may be underway in
India and Bangladesh. Pollution is not to blame. The culprit is arsenic in the drinking water, a natural phenomenon in several parts of
the world, but which is particularly severe in South Asia. Arsenic in ground water is caused naturally mainly by minerals dissolving
from weathered rocks and soils. Exposure to high levels of the toxic element can cause cancers of the skin, bladder, kidney, and
lung, and diseases of the blood vessels of the legs and feet, as well as possibly diabetes, high blood pressure, and reproductive
disorders………………
Keratoses of the foot
Decreasing
Toxicity
Why As speciation?
LD50 (mg/kg):
AsH3 - arsine (gas)
(3)*
As(III) - inorganic arsenite
(15)*
As(V) - inorganic arsenate
(87)*
MMA - monomethylarsonic acid
(1800)**
DMA - dimethylarsinic acid
(1200)**
TMAO - trimethylarsine oxide
(11600)**
AsB - arsenobetaine (marine)
(10000)
Arsenosugars (seaweed)
??
* Oral rat, ** Oral mouse
Toxicity of As is species
dependent!!!
As in Seaweed
O
75 mg As/kg dry mass
H 3C
As
HO
Non extractable
25%
OH
R=
As-sugar3
52%
As-sugar2
10%
R
CH3
DMA(V)
2%
As-sugar1
11%
O
1
OH
O
OH
2
O
O
O
P
OH
3
O
OH
SO3H
O
OH
Laminaria digitata/hyperborea
4
O
SO4H
What happens when we eat seaweed?
OH
OH
OH
Case study 1
Feeding trial, 12 sheep fed for 5 days
L. digitata
Urine + faeces
Samples
Total As determined by inductively coupled plasma mass spectrometry (ICP-MS)
Liquid sample introduction
•Urine
•Water
•Faeces digest
•Seaweed digest
ICP-MS
Dectection of m/z 75
(Agilent 7500c)
Total As
Results Total As
No obvious adverse health effects
As Intake by sheep:
As-excretion*:
As in sheep:
35 ± 6 mg As/day
Faeces 13 ± 10%
< 1% accumulating
(tissue, wool)**
1.7 ± 0.5 mg As/kg b. w.
Urine 86%
> 86% absorbed
As intake in Bangladesh:
4 L of 0.4 mg As/L
= 1.6 mg As/day
High absorption:
essential to study
metabolic products
Obvious health effects!!
*Hansen et al. Environ Sci Technol. 37, 2003
** Feldmann et al. Fresnius J Anal Chem 368, 2000 and Raab et al. Talanta 58, 2002
Analytical approach for speciation
Parallel use of HPLC-ICP-MS and HPLC-ES-MS
Liquid sample introduction
•Urine
•Water
•Faeces digest
•Seaweed digest
ICP-MS
Dectection of m/z 75
15%
HPLC
Sample introduction
(Agilent 1100 system)
Result
Chromatogram
(Agilent 7500c)
Column
Separation
85%
ES-MS
Molecular detection
Agilent HP1100 (LC/MSD))
Result
Chromatogram
Ex. As speciation in urine
Anion exchange column (HamiltonPRP-X100) 1 mL/ min 20 mM ammonium carbonate pH 8
O
H3C
As
S
H2S
COOH
H3C
As
CH3
CH3
120
A
B
1200000
1b
Fragmenter voltage (FV) 100 V
t=21.8 min
100
Abundance (%)
1: known species
1400000
COOH
197.0 [M+1]+
80
60
40
220.1
166.1
1000000
199.0
0
800000
U
Ua
2b
600000
1
U
21
41
61
81 101 121 141 161 181 201 221 241 261
Ub
3b
m/z
m/z
ICP-MS
ICP-MS
m/z75,
75
400000
m/zm/z199,
ES-MS
ESI-MS
199
m/z 137, ES-MS
ESI-MS m/z 137
200000
120
C
FV 240 V
t=21.8 min
100
Abundance (%)
Intensity (cps)
20
107.0 [AsS]+
80
60
40
91.0
20
m/z 197, ES-MS
109.0
ESI-MS m/z 197
0
0
10
20
30
Retention time (s)
40
50
60
0
1
21
41
61
81
m/z
101 121 141
Summary of Case Study 1
• HPLC-ICP-MS in combination with HPLC-ESMS(/MS) offers a superior method for As-speciation
&Novel As-species are continuously identified by this
method
&The first ever sulphur containing As-metabolite was
identified by this method (CASE STUDY 1) – at present
the toxicity and importance of sulphur-containing
arsenicals is unknown
• Both the As-species in the diet and their metabolites
must be studied for full evaluation of the toxicity of As
The poison Antimony
•ACUTE TOXICITY of Sb <<< As species (except SbH3)
•CHRONIC TOXICITY: similar symptoms as As, Sb3O2 (Sb(III)) is a suspected carcinogen
•INDUSTRIAL USE of Sb are many: Incl. Sb2O3 as a catalyst in PET plastic production
The poison lurking in your plastic water bottle
By JO KNOWSLEY, Daily Mail 10:22am 12th March 2006
Reader comments (22)
A Potentially deadly toxin is being absorbed into bottled mineral water from their plastic containers. And the longer the water is stored, the levels of poison increase, research
reveals. As the sell-by date on many bottled waters is up to two years, scientists have now called for extensive further studies.
The research by world expert Dr William Shotyk - who has vowed never to drink bottled water again - will be published in the Royal Society of Chemistry's journal next month.
It is sure to revive concerns about the safety of bottled water, the world's fastest-growing drinks industry, worth £1.2billion a year.
The tests found traces of antimony, a chemical used in the making of polyethylene terephthalate (PET) bottles, used by most mineral-water sellers.
Bottled water: Health fears
Small doses of antimony can make you feel ill and depressed. Larger quantities can cause violent vomiting and even death. The study stressed that amounts of antimony
were well below official recommended levels. But it also discovered that the levels almost doubled when the bottles were stored for three months.
Antimony is being
continuously released into bottled drinking water. The water in PET bottles is
contaminated."
Professor Shotyk, of Heidelberg University in Germany, said: "I don't want to shock people but here's what I know:
He tested ground water and 15 types of bottled mineral water in his native Canada. The ground water contained two parts per trillion (ppt) of antimony. Bottled water had an
average 160 ppt of antimony when opened immediately after bottling. But ground water stored in a PET plastic bottle had 630 ppt of antimony when opened six months later.
Professor Shotyk then tried the experiment in Europe, collecting 48 brands of water in PET bottles and water from its source in the ground at a German bottling plant. The
Case study 2: Analysis of citricjuices contained in PET bottles
QUESTIONS:
1) What are the Sb-concentrations in juices?
2) Which Sb-species are present in juices/water?
EXPERIMENTAL SET-UP:
Total Sb analysis and Sb speciation of
water and carbonated or non-carbonated citrus fruit drinks contained in:
1) PET bottles
2) Glass bottles
3) Tetra packs
Total Sb in juices stored in PET
containers
concentration (μg Sb/L)
1.2
y = 0.0019x + 0.6174
2
R = 0.5671
0.8
0.4
Max 1.05 μg Sb/L
(below guidelines:WHO, 20 μg Sb/L;
US EPA, 6 μg Sb/L and Japan 2 μg
Sb/L )
0
-125
-75
-25
25
75
Days before (-) and after (+) expiration
125
175
Total Sb in juices in PET bottles shows correlation to the expiration date
Results Sb speciation by
HPLC-ICP-MS
Water in PET
Citrus fruit juices in PET
5000
Identity confirmed by spiking
5000
5000
0.5 ppb Sb(V)
2500
Intensity (cps)
(cps)
Intensity
Intensity (cps)
+ 0.5 ppb Sb(III)
2) Sb(III)
sample
2500
2500
sample + 0.5 ppb Sb(III)
3) Sb(V)-citrate
3) Sb(V)-citrate
1) Sb(V)
0
0
0.5
1
1.5
2
Retention time (min)
100% Sb(V)
2.5
3
3.5
00
00
0.5
0.5
11
1.5
22
1.5
Retention
time
Retention time (min)
(min)
2.5
2.5
33
3.5
3.5
Sb(III): 44 ±17% (n=11)
*Sb(V)-citrate: 41 ± 20% n=11)
* Hansen, H. R. and Pergantis, S. A. JAAS, submitted
Summary of Case Study 2
• Elevated Sb concentrations are present in juices
stored in PET bottles (0.28 to 1.05 μg Sb/L)
compared to juices in Tetra packs (0.07 ± 0.06
μg Sb/L).
• By speciation it is revealed that the carcinogenic
form of antimony, Sb(III), is preserved by the
citric acid in fruit juices and a complex of
unknown toxicity is present.
Arsenic and Antimony:
Poisons or Not?
Element Speciation Analysis has the Answer
• No simple answer
• Speciation is essential!
• No, by speciation the chemical forms of
the element can be determined, but it is up
to the toxicologist to give the answer
Acknowledgment
• Prof. S. A. Pergantis, University of Crete,
Department of Chemistry, Environmental
Chemical Processes Laboratory
• Prof. J. Feldmann, University of Aberdeen,
Department of Chemistry, TESLA