Flow Injection Hydride Generation

SPECTROSCOPIC TECHNIQUE IN ANALYTICAL CHEMISTRY

KIM 3401

GROUP MEMBERS;NAME UK NUMBER

SIM FONG CHIT UK 24791

NURUL SYAZDIANA BINTI MOHD ZUKI

UK 26258

NORSHARINA BINTI MOHD PESOL UK 25643

(Flow Injection Hydride Generation Atomic Absorption Spectrometry)

What is ARSENIC?

Found naturally in rocks and soil, water, air, and in plants and

animals.

Has no taste or smell

Arsenic 33rd element in Periodic Table. Highest priority contaminant. Refer:

http://www.atsdr.cdc.gov/SPL/index.html Known as poison and human carcinogen. Long-term exposure:

change the way cells communicatedevelopment of diabetesCancerlung disease

Arsenic

Inorganic form found in industry, and in arsenic-contaminated water. It tends to be more toxic and has been linked to

cancer.

Organic form are much less toxic than the inorganic arsenic compounds and are not thought to be linked to cancer. found in some foods, such as fish and shellfish.

How are people exposed to Arsenic?

At workIn the community

In drinking water

In food

CASE STUDY

CHRONOLOGY of Arsenic Pollution in West Bengal, India

Arsenic natural geological is present in local bedrock. Using of pesticides, fertilizers in agrochemical field.The Arsenic from pesticides and fertilizers percolated

into the ground.Using of deep tube wells for water supply and power

pump.The deeper the level of groundwater, the higher the

concentration of Arsenic.

CHRONOLOGY cont..The deep tube wells continue pulling up the deep

Arsenic, therefore the situation became worst.People used the water from the tube well,

unknowingly they were transferring the Arsenic to their body.

Epidemiological study was carried out. Water samples were obtained from the tube wells.

0.84 million people exposed to Arsenic, 0.14 million people suffering arsenical skin lesion.

Effect of Arsenic in humanCancer in the skin, lungs, bladder and kidneySkin changes such as thickening and pigmentationBlackfoot disease

How to prevent?

• Diet• Change the way to cook the rice• Vary with other grains

INSTRUMENTATION

Flow InjectionHydride Generation

Atomic Absorption Spectrometry(FI-HG-AAS)

FLOW IN JECTION

AAS

HG-AAS

http://www.shsu.edu/~chm_tgc/sounds/sound.html

Advances of InstrumentFlow injection• consists of two peristaltic pumps

1. for pumping the carrier and reducing agents 2. for pumping the sample solution.

• A certain volume of the sample injected into the flow of carrier liquid

Hydride Generation• the volatile sample is stripped from the analyte solution and

carried out by a gas into the atomizer.

• This strip is followed by chemically converting the analyte to hydride vapor form.

Flow Injection Hydride Generation Atomic Absorption

Spectrometry

Inductively-Coupled Plasma Mass Spectrometry

Detection limit 0.02µg/L 0.2 µg/L

Nebulizer Nebulizer is not required Nebulizer is required

Precision 0.1-1% 1-3%

Dissolved solids maximum concentration

0.5-3 0.1-0.4

Chlorine interference Less More (1µg/L for each 100mg/L)

Linear dynamic range 103 105

Sample throughput 15seconds/elements 2-6minutes all elements

Operation cost Low High

Advantages of FI-HG-AAS

• low detection limits• quite fast measurement• most of interferences disappear when the analyte is

transferred to a gaseous state

Disadvantages of FI-HG-AAS

• the specific chemical form of the analyte is required• high concentrations of Cu, Ni, platinum group metals and other

transition metals cause serious interferences• a large excess of the hydride-forming element makes

determination of traces of the other one impossible

CONCLUSION