In Israel, desalinated water is a major source of drinking water. Previous studies have suggested that the levels of iodine in water provided by authorities may not accurately reflect the levels reaching end-users. Materials and Methods: We analyzed 21 tap water samples collected from different localities across Israel, 13 posttreated desalinated water samples from three of the largest Israeli desalination plants, and several natural water samples. An improved method of ICP-MS developed in our laboratory was used to analyze the content of iodine and other macro-elements, and determination of iodine was performed in alkaline media. Results: Our results showed that it is possible to distinguish between sample groups based on iodine concentration, water hardness, and Ca/Mg ratio. The median iodine concentrations for four groups of tap water samples ranged from 0.3 to 12.3 μg/L, which is lower than the concentrations previously reported by other researchers in Israel. Based on typical consumption, the water samples can provide no more than 3.39% of the recommended dietary allowance level for iodine. The analysis of post-treated desalinated water samples indicated that these waters comply with industrial specifications but contain only trace concentrations of iodine and much less magnesium than recommended by different public health authorities for public consumption of drinking water. Conclusion: The total iodine concentrations found were lower than several observations reported in previous years in the literature. There are currently no strict regulations regarding iodine and magnesium levels in drinking and/or softened (desalinated) water, but the intensive desalination plant application is already exhibiting a negative impact on public health. Further investigations are needed, but the present study provides useful insights for developing an effective policy to ensure adequate iodine supply for the population of Israel through drinking water.

1. Determination of Total Iodine
using ICP-MS in Israeli Bottled
and Tap Water: Method
Development and Application
Dr Vasiliy V. Rosen
icpaes@gmail.com
The Scientific Service Core Facility
The Faculty of Agriculture
The Hebrew University of Jerusalem
January 17, 2023
The Team:
Dr Orit Gal
Yuliana Andrushchenko, M.Sc.
Prof. Yona Chen

2. Agenda
The Scientific Service Core Facility January 18, 2023 Slide No. 2
❑Iodine in drinking water in the desalination era
❑Iodine determination challenges
❑ICP-MS method improvement
❑Iodine in Israel: Tap water vs Bottled water

3. The Scientific Service Core Facility January 18, 2023 Slide No. 3
Iodine in drinking water in the desalination era
❖ Essential micro-element for human health
❖ The standard still not established, but: risk-reducing
concentrations of iodide in drinking water is about
5 – 50 µg L-1
❖ RDA 150 µg d-1
❖ EAR 95 µg d-1
for females and males of age 14-50 y.
❖ Discovered in 1811
❖ Occurs in water mostly as iodate I-

4. Iodine in drinking water in the desalination era
❖Do we consume enough iodine in Israel?
The Scientific Service Core Facility January 18, 2023 Slide No. 4

5. Iodine in drinking water in the desalination era
2007
The Scientific Service Core Facility January 18, 2023 Slide No. 5

6. Iodine in drinking water in the desalination era
Ashkelon Desalination Plant
118 million m3 per year
Tenne A. et al., 2012
❖Desalination plants are
providing about 80% of
potable water used in
households across Israel
❖Iodine in tap water:
Ashkelon District: 2003 – 52 µg L-1 ,
2008 - 27 µg L-1 (Gefel et al., 2016)
4 -20 µg L-1 (Barnett-Izhaki et al., 2022)
The Scientific Service Core Facility January 18, 2023 Slide No. 6

7. Organically-
bound Iodine
(Organic
Iodides)
Iodide I- Iodate IO3-
Free Iodine I2
3I2 + 3H2O = HIO3 + 5HI
In the alkaline media
In the acidic media
volatile non-
volatile
Iodine determination challenges
The Scientific Service Core Facility January 18, 2023 Slide No. 7

8. ICP-MS Method Improvement
Iodine using ICP-MS
Superior sensitivity (LOQ~0.01 µg L-1)
High-throughput method
Expensive equipment
Method development challenge
+2% NH4OH, pH>10
The Scientific Service Core Facility January 18, 2023 Slide No. 8

9. +2% NH4OH, pH>10
+2% NH4OH, pH>10
+0.1% EDTA
Carbonates precipitated
ICP-MS nebulizer
clogged
Carbonates have not formed
No clogging!
ICP-MS Method Improvement
The Scientific Service Core Facility January 18, 2023 Slide No. 9

10. ICP-MS Method Improvement
The Scientific Service Core Facility January 19, 2023 Slide No. 10

11. ICP-MS Method Improvement
Result Obtained (n=5):
The Scientific Service Core Facility January 18, 2023 Slide No. 11

12. Method
Precision
ICP-MS Method Improvement
The Scientific Service Core Facility January 18, 2023 Slide No. 12

13. ICP-MS Method Improvement
Cs133
Ge72
I127
Internal Standard for I127
Element
Abundance,
%
Ion Potential,
eV
Atomic Mass,
amu
Cs 27.6 3.89 132.9
Ge 100 7.89 72.6
I 100 10.5 126.9
The Scientific Service Core Facility January 18, 2023 Slide No. 13

14. ICP-MS Method Improvement
The Scientific Service Core Facility January 18, 2023 Slide No. 14

15. ICP-MS Method Improvement
The Scientific Service Core Facility January 18, 2023 Slide No. 15

16. ❖ Iodine is stable in
matrices A and E
❖ Iodine is stable in
original water sample
during 2 weeks at +4 ºC
or at room temperature
as is
+4 ºC
Room T
ICP-MS Method Improvement
The Scientific Service Core Facility January 18, 2023 Slide No. 16

17. Total Iodine Concentration in Mineral Bottled Waters in Israel, µg L-1
Aqua Nova
<0.1
Evian
1.53±0.03
S.Benedetto
3.47±0.03
Neviot
5.22±0.07
Mei Eden
6.89±0.13
Brand F
6.96±0.23
Brand G
8.46±0.11
Brand H
21.13±0.45
Tap Water
2.99±0.06
Iodine in Israel: Tap water vs Bottled water
7.68±2.41 µg L-1
(average ± standard error)
7 ± 5.7 µg L-1
(Benbassat et al., 2004)
The Scientific Service Core Facility January 18, 2023 Slide No. 17

18. Iodine in Israel: Tap water vs Bottled water
Median values range
for all the samples
0.3 – 12.3 µg I L-1
Group A
<1 µg I L-1
Group B
1-4 µg I L-1
Group C
4-8 µg I L-1
Group D
8-20 µg I L-1
Total iodine in tap water
The Scientific Service Core Facility January 18, 2023 Slide No. 18

19. Iodine in Israel: Tap water vs Bottled water
The Scientific Service Core Facility January 18, 2023 Slide No. 19

20. Iodine in Israel: Tap water vs Bottled water
The Scientific Service Core Facility January 18, 2023 Slide No. 20

21. Iodine in Israel: Tap water vs Bottled water
Total iodine in natural waters
The Scientific Service Core Facility January 18, 2023 Slide No. 21

22. Iodine in Israel: Tap water vs Bottled water
Ca/Mg
36.2
Ca/Mg
14.6
Ca/Mg
2.56
Ca/Mg
2.44
Ca/Mg
66.1
Ca/Mg
169
Ca/Mg
31.3
The Scientific Service Core Facility January 18, 2023 Slide No. 22

23. Iodine in Israel: Tap water vs Bottled water
The hourly and yearly dynamics of iodine in tap water
CV 12%
CV 56%
CV 151%
The Scientific Service Core Facility January 18, 2023 Slide No. 23

24. Conclusions
+2% NH4OH, pH>10
+0.1% EDTA
LOQ is 0.04 – 0.1 µg I l-1
2 weeks stability Iodine deficiency is
possible 
The Scientific Service Core Facility January 18, 2023 Slide No. 24

25. The Team:
Dr. Orit Gal Garber
Yuliana Andrushchenko, M.Sc.
Prof. Yona Chen
Dr. Vasiliy V. Rosen