pptfinal! (2)
TRANSCRIPT
-
7/30/2019 PPTfinal! (2)
1/25
Pollutant analysis by spectroscopy methods
5 TH Course of Chemistry Degree
Jos Antonio Alonso Domnguez
Roco Barreiro Rodrguez
-
7/30/2019 PPTfinal! (2)
2/25
Introduction
Toxicity of the inorganic arsenic
Legislation
Analytical methods
Literature sources
-
7/30/2019 PPTfinal! (2)
3/25
Arsenic is a chemical element whose namecomes from the Greek 'Aarsenkon', meaning'powerful'.
It was obtained around 1250 by AlbertoMagno heating arsenic oxide with soap.
Are known compounds of arsenic from
antiquity, were used as a poison because ofits extreme toxicity. In contrast, from arsenicalso got the first effective medicine to treatsyphilis.
-
7/30/2019 PPTfinal! (2)
4/25
Historically there have beenmajor disasters due to arseniccontamination. An example of adisaster that remains today is in
Bangladesh .
The University of California,Berkeley after working forseveral weeks camp closed its
report warning "a tragedy thatexceeds 10 times that ofChernobyl
-
7/30/2019 PPTfinal! (2)
5/25
In Argentina, more than a 100locations in the provinces ofBuenos Aires, La Pampa, Salta,
San Luis, Cordoba and other is arate of As contained in drinkingwater.
The origin of the problem is thevolcanic ash resulting from theformation of the Andes, whichcontaminate groundwater.
-
7/30/2019 PPTfinal! (2)
6/25
The environmental contamination and mobilityof arsenic is conditioned primarily by the
redox conditions and the pH of the waterenvironment. The phosphate, if it is present ina concentration greater than arsenic, will actas a competitor In the arsenic fixation.
Arsenic comes in various
oxidation states, As0, or as ions:
As5 +, As3 +, and As3-.
-
7/30/2019 PPTfinal! (2)
7/25
Regarding the diabetogenic effect ofarsenic, (Tseng et al. 2004), proposesoxidative stress and interference withfactor of transcription as the most likelycauses. Through induction of insulinresistance and beta cell dysfunction.
Arsenite at low concentration, inhibitsan important nuclear receptor ofhormones, that activate the insulin.
-
7/30/2019 PPTfinal! (2)
8/25
The epidemiological studies in Taiwan, Chile, Argentina and
Mexico showed that arsenic was diabetogenic.
In Taiwan, in studies carried out inrecent decades confirms theassociation between exposure toarsenic and disorders such asdiabetes mellitus, hypertension,heart disease, stroke.
More recent studies suggest thatthe risk of disease is associatedwith the inability of the individual tofully methylate inorganic arsenic.
-
7/30/2019 PPTfinal! (2)
9/25
In Mexico, a study recognized by the AMC shows that exposure toArsenic is a clear risk factor for disease development.
In rats was found that low-dose arsenic, pancreatic beta cells did notdie, however, it was observed that the cells lost their ability torecognize the extracellular glucose concentration.
It was also concluded that arsenic interferes insulin secretion byaltering levels of intracellular free calcium.
80 individuals were studied, which were 50% are diabetics. Inconclusion, when it came to diabetic patients, it was found that the
higher the concentration of arsenic in the urine, the percentage ofbeta cell function declines with an exponential pattern, although itwas noted that arsenic exposure seems to be sufficient to trigger thedisease but it is a clear risk factor that should be taken into account.
-
7/30/2019 PPTfinal! (2)
10/25
Millions of individuals worldwide are exposed to drinking
water contaminated with inorganic arsenic (arsenite and
arsenate) mainly from natural mineral deposits.
-
7/30/2019 PPTfinal! (2)
11/25
Inorganic arsenic is classified by the U.S. EPA as a knownhuman carcinogen, based on extensive population studies
of lung cancers following inhalation exposure, and skin
cancers following ingestion of contaminated drinking water
in adults.
-
7/30/2019 PPTfinal! (2)
12/25
Other effects of chronic arsenic exposure reported foradults include kidney damage and failure, anemia, low
blood pressure and shock, and central nervous system
symptoms such as headaches, weakness, and delirium.
Chronic arsenic exposure of children and adults has been
associated with adverse liver and respiratory effects,
including irritation of mucous membranes.
During development, chronic high level inorganic arsenic
exposure in humans was associated with increased
incidence of preterm delivery, miscarriage, stillbirths, low
birth weight, and infant mortality.
-
7/30/2019 PPTfinal! (2)
13/25
Inorganic arsenic exposure during childhood wasassociated with decreased performance in tests of
intelligence (I.Q.) and long-term memory.
Acute exposure (14 days or less, including single exposure)of adults and children resulted in gastrointestinal effects,
such as nausea, vomiting, abdominal pain, and diarrhea;
and neurological effects (e.g., headaches, dizziness) on the
central and peripheral nervous system.
Acute one-time exposure of adults of approximately 22-600
g/day has resulted in death.
-
7/30/2019 PPTfinal! (2)
14/25
Furthermore, inorganic arsenic may be an increased risk ofdiabetes in chronically-exposed adults and children
because relatively high concentrations increased glucose
and insulin levels, decreased glucose uptake in insulin
sensitive cells and interfered with transcription factorsinvolved in insulin signal transduction and insulin sensitivity
in vitro.
-
7/30/2019 PPTfinal! (2)
15/25
Additionally, humans are exposed to organic arseniccompounds such as arsenobetaine and arsenosugars,
mainly from seafood, but they are nontoxic.
-
7/30/2019 PPTfinal! (2)
16/25
In Spain until 1990 the level of arsenic allowed in drinkingwater was 100g/L.
It was not until October 3, 1990 when the Royal Decree1138/90 was approbed. This RD which sets the limit for
drinking water in 50g/L, this limit is still too high if weconsider the limit recommended by the World HealthOrganization which is set at 10g/L.
From Europe, Directive 98/83/EC sets the limit of 10g/L limitcoinciding with the WHO recommendation and EPA but not
until January 7, 2003 when enters into force transposing thestandard European to Spain by approval the RealDecreto140/2003 establishing health criteria of drinking waterin countries with severe arsenic poisoning.
Argentina would not adopt this limit of 10g/L to 2007.
-
7/30/2019 PPTfinal! (2)
17/25
In Spain have not been established ceilings of inorganicarsenic in aliments.
Currently, Australia and New Zealand only limited to 1mg/kgfresh weight of inorganic arsenic content in fish products.
World Health Organization has set the limit for wet weight foodof 2 mg/Kg. The limits for shellfish is 50 to 100 mg/Kg and forfish 3 to 5 mg/kg.
In actually is presenting a bill to limit the amount of arsenic
allowed in rice and rice-based products, following aninvestigation by Consumer Reports found that very high levelsof arsenic in more than 200 samples of this cereal and itsderivatives.
-
7/30/2019 PPTfinal! (2)
18/25
There are many analytical methods for the determination
of inorganic arsenic. The most used are:
HG-ICP-MS
HG-AAS Electroanalysis
Others:
IC-ICP-MS AFS
-
7/30/2019 PPTfinal! (2)
19/25
HPLC-HG-ICP-MS
A cyclonic spray chamber was connected to the T piece and the sample gas flow mixed with thenebulised continuous internal standard creating stable wet plasma conditions. For the analysis,the ICP-MS was optimised for optimal sensitivity and stability on arsenic that has an m/z of 75.
The sample flow was passed through a reaction coil of Teflon into a gas-liquid separator. Thegaseous products were transported via an argon flow to a glass T piece connected directly to the
torch.
An HPLC system was connected directly to a continuous-flow HG system. Acid (3 M, HCl) andNaBH4 (1.5% w/v, in 0.1M NaOH) were mixed with the sample post column via two T pieces.
Acid and NaBH4 flows were regulating using a peristaltic pump.
The separation and detection of anionic arsenic species in the sample extracts were carried outon a column with a flow rate of 1 mLmin-1. As mobile phase, 6.2 mM NH4NO3 and 6.5 mM
H3PO4 adjusted to a pH of 6.0 was used.
-
7/30/2019 PPTfinal! (2)
20/25
HPLC-HG-ICP-MS
Schematic of HPLC-HG-ICP-MS system:
-
7/30/2019 PPTfinal! (2)
21/25
SPE-HG-AAS
The hydrides were swept to a gasliquid separator using argon gas and transported through a
dryer tube to the electrically heated open-ended T-shaped silica cell of the atomic absorptionspectrometer. Data were collected by the SOLAAR software.
The HG-AAS system was operated according to the manufacturers instructions. Theautosampler introduced the pre-reduced sample to the vapour generator where it reacted withfreshly prepared NaOH/NaBH4 (0.5%w/v) and HCl (4.7 M) solutions to generate gaseousarsenic
hydrides (AsH3) from AsIII.
A pre-reduction was carried out by mixing 1 mL of SPE eluate with 7 mL of reduction solution,which react for 1 h at room temperature. Furthermore, 6 ml of 3 M HCl was added, and it was left
to react for another hour at room temperature.
Inorganic arsenic was selectively separated from other arsenic compounds using strong anionexchange SPE. Optimal performance was obtained using a silica-based SPE cartridge with a
flow rate of ~1 mlmin1. The procedure required a pre conditioning and a post analysis wash ofthe cartridge .
-
7/30/2019 PPTfinal! (2)
22/25
SPE-HG-AAS
HG-AAS system:
SPE cartridge:
-
7/30/2019 PPTfinal! (2)
23/25
ELECTROANALYSIS: Differential-puIseCathodic Stripping Voltammetry
Auxiliary electrode: platinum rod
Reference electrode: Ag/AgCl/KCl(3 M) Working electrode: an HMDE
-
7/30/2019 PPTfinal! (2)
24/25
ELECTROANALYSIS:
The initial potential was set at -0.5 V and, after extrusion of a new mercury drop, arsenic wascollected with stirring for 120 s. The stirrer was stopped and, after a 20 s rest period, the scan was
begun in the negative direction using the differential-pulse (DP) mode with an electrode area of0.50 mm2, a sweep rate of 6.6 mVs-l and a pulse modulation of -50 mV.
A 0.2 g amount of KI and 0.4 g of NaHC03 were weighed in the voltammetric cell and then 10 mlof concentrated HCl and 10 ml of water were added. After dissolution, a volume of soil solution
(50-200 L) was added to the cell.
After the samples had reached room temperature, they were filtered and diluted to 50 mL withwater. These solutions were passed through a Sep-Pak C18 cartridge, previously activated with 5
mL of methanol and 10 mL of water.
Soil samples were dried, homogenized and sieved. A 0.5 g amount of soil was weighed in a PTFEbeaker, 2 ml of concentrated HNO3 and 6 ml of concentrated HCl were added and the beaker wasclosed and placed in the microwave digester. Digestion was carried out with the sample treatedfor 10 min at a pressure of 120 psi with a maximum power of 650 50W.
-
7/30/2019 PPTfinal! (2)
25/25
Ana Navas-Acien, Ellen K. Silbergeld, Roberto Pastor-Barriuso, Eliseo Guallar, ArsenicExposure and Prevalence of Type 2 Diabetes in US Adults, J. Am. Med. Assoc., 300/7(2008) 814-822.
http://www.epa.gov/teach/chem_summ/Arsenic_summary.pdf http://designbuildsource.com.au/rust-solution-arsenic-contaminated-water http://www.18andundermd.com/general/an-elemental-problem.html http://sciencelife.uchospitals.edu/2011/05/11/two-public-health-wrongs-make-it-worse/ http://www.empowher.com/media/reference/arsenic-toxicity
http://www.topnews.in/health/diseases/diabetes?page=6 http://www.sigmaaldrich.com/catalog/product/FLUKA/BCR626?lang=es®ion=ES http://upload.wikimedia.org/wikipedia/commons/a/af/Arsenosugars.svg http://www.pfc-asia.net/fresh_seafood.php Ptursdttir, A.H., Gunnlaugsdttir, H., Jrundsdttir, H., Mestrot, A., Krupp,
E.M., Feldmann, J., HPLC-HG-ICP-MS: a sensitive and selective method for inorganicarsenic in seafood, Anal. Bioanal. Chem. (2012) 404:21852191.
Rasmussen, R.R., Hedegaard, R.V., Larsen, E.H., Sloth, J.J., Development and validationof an SPE HG-AAS method for determination of inorganic arsenic in samples of marine
origin, Anal. Bioanal. Chem. (2012) 403:28252834. http://www.und.edu/dept/earl/Major%20instrument.htm http://www.kemomed.si/vsebina?x=1&y=6&z=38&u=47 I. Eguiarte , R. M. Alonso and R. M. Jimnez, Determination of total arsenic in soils by
differential-pulse cathodic stripping voltammetry, Analyst, 1996,121, 1835-1838. http://www.ff.uc.pt/labmia/english/equipamentos.htm http://www.ceb.cam.ac.uk/pages/hydrodynamic-voltammetry.html
http://faculty.jhsph.edu/?F=Ana&L=Navas-Acienhttp://faculty.jhsph.edu/?F=Ellen&L=Silbergeldhttp://www.epa.gov/teach/chem_summ/Arsenic_summary.pdfhttp://designbuildsource.com.au/rust-solution-arsenic-contaminated-waterhttp://www.18andundermd.com/general/an-elemental-problem.htmlhttp://sciencelife.uchospitals.edu/2011/05/11/two-public-health-wrongs-make-it-worse/http://www.empowher.com/media/reference/arsenic-toxicityhttp://www.topnews.in/health/diseases/diabetes?page=6http://www.sigmaaldrich.com/catalog/product/FLUKA/BCR626?lang=es®ion=EShttp://upload.wikimedia.org/wikipedia/commons/a/af/Arsenosugars.svghttp://www.pfc-asia.net/fresh_seafood.phphttp://www.scopus.com/authid/detail.url?authorId=49962062600&eid=2-s2.0-84865311168http://www.scopus.com/authid/detail.url?authorId=6602821361&eid=2-s2.0-84865311168http://www.scopus.com/authid/detail.url?authorId=12791087800&eid=2-s2.0-84865311168http://www.scopus.com/authid/detail.url?authorId=23568620200&eid=2-s2.0-84865311168http://www.scopus.com/authid/detail.url?authorId=6603449529&eid=2-s2.0-84865311168http://www.scopus.com/authid/detail.url?authorId=6603449529&eid=2-s2.0-84865311168http://www.scopus.com/authid/detail.url?authorId=35547990100&eid=2-s2.0-84865311168http://www.scopus.com/authid/detail.url?authorId=25927510600&eid=2-s2.0-84863778762http://www.scopus.com/authid/detail.url?authorId=6507948853&eid=2-s2.0-84863778762http://www.scopus.com/authid/detail.url?authorId=35429811100&eid=2-s2.0-84863778762http://www.scopus.com/authid/detail.url?authorId=6602875982&eid=2-s2.0-84863778762http://www.und.edu/dept/earl/Major%20instrument.htmhttp://www.kemomed.si/vsebina?x=1&y=6&z=38&u=47http://www.ff.uc.pt/labmia/english/equipamentos.htmhttp://www.ceb.cam.ac.uk/pages/hydrodynamic-voltammetry.htmlhttp://www.ceb.cam.ac.uk/pages/hydrodynamic-voltammetry.htmlhttp://www.ceb.cam.ac.uk/pages/hydrodynamic-voltammetry.htmlhttp://www.ceb.cam.ac.uk/pages/hydrodynamic-voltammetry.htmlhttp://www.ff.uc.pt/labmia/english/equipamentos.htmhttp://www.kemomed.si/vsebina?x=1&y=6&z=38&u=47http://www.und.edu/dept/earl/Major%20instrument.htmhttp://www.scopus.com/authid/detail.url?authorId=6602875982&eid=2-s2.0-84863778762http://www.scopus.com/authid/detail.url?authorId=35429811100&eid=2-s2.0-84863778762http://www.scopus.com/authid/detail.url?authorId=6507948853&eid=2-s2.0-84863778762http://www.scopus.com/authid/detail.url?authorId=6507948853&eid=2-s2.0-84863778762http://www.scopus.com/authid/detail.url?authorId=25927510600&eid=2-s2.0-84863778762http://www.scopus.com/authid/detail.url?authorId=35547990100&eid=2-s2.0-84865311168http://www.scopus.com/authid/detail.url?authorId=35547990100&eid=2-s2.0-84865311168http://www.scopus.com/authid/detail.url?authorId=6603449529&eid=2-s2.0-84865311168http://www.scopus.com/authid/detail.url?authorId=6603449529&eid=2-s2.0-84865311168http://www.scopus.com/authid/detail.url?authorId=23568620200&eid=2-s2.0-84865311168http://www.scopus.com/authid/detail.url?authorId=23568620200&eid=2-s2.0-84865311168http://www.scopus.com/authid/detail.url?authorId=12791087800&eid=2-s2.0-84865311168http://www.scopus.com/authid/detail.url?authorId=12791087800&eid=2-s2.0-84865311168http://www.scopus.com/authid/detail.url?authorId=6602821361&eid=2-s2.0-84865311168http://www.scopus.com/authid/detail.url?authorId=6602821361&eid=2-s2.0-84865311168http://www.scopus.com/authid/detail.url?authorId=49962062600&eid=2-s2.0-84865311168http://www.scopus.com/authid/detail.url?authorId=49962062600&eid=2-s2.0-84865311168http://www.pfc-asia.net/fresh_seafood.phphttp://www.pfc-asia.net/fresh_seafood.phphttp://www.pfc-asia.net/fresh_seafood.phphttp://upload.wikimedia.org/wikipedia/commons/a/af/Arsenosugars.svghttp://www.sigmaaldrich.com/catalog/product/FLUKA/BCR626?lang=es®ion=EShttp://www.topnews.in/health/diseases/diabetes?page=6http://www.empowher.com/media/reference/arsenic-toxicityhttp://www.empowher.com/media/reference/arsenic-toxicityhttp://www.empowher.com/media/reference/arsenic-toxicityhttp://sciencelife.uchospitals.edu/2011/05/11/two-public-health-wrongs-make-it-worse/http://sciencelife.uchospitals.edu/2011/05/11/two-public-health-wrongs-make-it-worse/http://sciencelife.uchospitals.edu/2011/05/11/two-public-health-wrongs-make-it-worse/http://sciencelife.uchospitals.edu/2011/05/11/two-public-health-wrongs-make-it-worse/http://sciencelife.uchospitals.edu/2011/05/11/two-public-health-wrongs-make-it-worse/http://sciencelife.uchospitals.edu/2011/05/11/two-public-health-wrongs-make-it-worse/http://sciencelife.uchospitals.edu/2011/05/11/two-public-health-wrongs-make-it-worse/http://sciencelife.uchospitals.edu/2011/05/11/two-public-health-wrongs-make-it-worse/http://sciencelife.uchospitals.edu/2011/05/11/two-public-health-wrongs-make-it-worse/http://sciencelife.uchospitals.edu/2011/05/11/two-public-health-wrongs-make-it-worse/http://sciencelife.uchospitals.edu/2011/05/11/two-public-health-wrongs-make-it-worse/http://sciencelife.uchospitals.edu/2011/05/11/two-public-health-wrongs-make-it-worse/http://sciencelife.uchospitals.edu/2011/05/11/two-public-health-wrongs-make-it-worse/http://www.18andundermd.com/general/an-elemental-problem.htmlhttp://www.18andundermd.com/general/an-elemental-problem.htmlhttp://www.18andundermd.com/general/an-elemental-problem.htmlhttp://www.18andundermd.com/general/an-elemental-problem.htmlhttp://www.18andundermd.com/general/an-elemental-problem.htmlhttp://designbuildsource.com.au/rust-solution-arsenic-contaminated-waterhttp://designbuildsource.com.au/rust-solution-arsenic-contaminated-waterhttp://designbuildsource.com.au/rust-solution-arsenic-contaminated-waterhttp://designbuildsource.com.au/rust-solution-arsenic-contaminated-waterhttp://designbuildsource.com.au/rust-solution-arsenic-contaminated-waterhttp://designbuildsource.com.au/rust-solution-arsenic-contaminated-waterhttp://designbuildsource.com.au/rust-solution-arsenic-contaminated-waterhttp://designbuildsource.com.au/rust-solution-arsenic-contaminated-waterhttp://designbuildsource.com.au/rust-solution-arsenic-contaminated-waterhttp://www.epa.gov/teach/chem_summ/Arsenic_summary.pdfhttp://faculty.jhsph.edu/?F=Ellen&L=Silbergeldhttp://faculty.jhsph.edu/?F=Ellen&L=Silbergeldhttp://faculty.jhsph.edu/?F=Ellen&L=Silbergeldhttp://faculty.jhsph.edu/?F=Ana&L=Navas-Acienhttp://faculty.jhsph.edu/?F=Ana&L=Navas-Acienhttp://faculty.jhsph.edu/?F=Ana&L=Navas-Acienhttp://faculty.jhsph.edu/?F=Ana&L=Navas-Acien