here is a report on the tea analysis done by students of St. Johns's College Agra

1. A PROJECT REPORT ON
DETERMINATION OF SOME HEAVY METAL LEVELS
IN TEA SAMPLES USING FLAME ATOMIC
ABSORPTION SPECTROPHOTOMETER (FAAS)
SUBMITTED TO
DEPARTMENT OF CHEMISTRY, ST. JOHN’S COLLEGE, AGRA
FOR THE DEGREE OF MASTER OF SCIENCE (M Sc)
IN PHYSICAL CHEMISTRY (2013-2014)
UNDER THE SUPERVISION OF:
Dr. SUSAN VERGHESE .P
Associate Professor
Department of Chemistry
St. John’s College, Agra
SUBMITTED BY:
SHOWKAT ALI BHAT
M Sc Final
Physical Chemistry
2013-14

2. CERTIFICATE
This is to certify that this project entitled “DETERMINATION OF
SOME HEAVY METAL LEVELS IN TEA SAMPLES USING FLAME
ATOMIC ABSORPTION SPECTROPHOTOMETER (FAAS)” submitted
to St. John’s College, Agra, for the fulfillment of the requirement
for the Master degree is a bona fide project work carried out by
SHOWKAT ALI BHAT student of M Sc Final (PHYSICAL CHEMISTRY)
under my supervision and guidance during the session 2013-2014.
The assistance and help rendered during the course of
investigation and sources of literature have been acknowledged.
Dr. Susan Verghese .P
Associate Professor
Department of Chemistry
St. John’s College, Agra
(Supervisor)
Dr. Hemant Kulshreshtha
HEAD
Department of Chemistry
St. John’s College, Agra

3. ACKNOWLEDGEMENT
It is my proud privilege to express my profound sense of gratitude
and sincere indebtedness to honorable Dr Alexander Lal, Principal of
St. John’s College, Agra, for providing infrastructure for the
completion of this project. I am thankful to Dr Hemant Kulshreshtha,
Head of the Chemistry Department; he was always affectionate,
pain taking and source of inspiration to me. I am highly obliged to
him for their guidance, constructive criticism and valuable advice
which they provided to me throughout the tenure of my project.
The project work could not have been possible without his worthy
suggestions and constant co-operation.
I am also thankful to my supervisor Dr Susan Verghese to guide me
on the various sides of this project and her help and guidance she
provided to me for the initiation of this project. My heart is filled
with deep sense of thankfulness and obeisance to my teachers Dr. R
P Singh, Dr. H B Singh, Dr. P E Joseph, Dr. Raju V John, Dr. Shalini
Nelson, Dr. Mohd. Anis, Dr. Anita Anand, Dr. Padma Hazra, and Dr.
David Massey for their valuable suggestions and lively moral
boosting during the progress of this investigation.
I am also thankful to Ms. Nisha Siddhardhan (Instrumentation in-
charge) for their kind support during the project work. I also place
my sincere thanks to non-teaching staff for their support and co-
operation.
I am highly grateful to my parents for their affectionate and moral
support. They have always been source of inspiration for me.
Above all, I thank The Almighty for giving me strength to complete
this project.
Last but not the least I extend my sincere thanks to all those who
have helped me in one or the other way during my project work.
SHOWKAT ALI BHAT
M Sc Final (Physical Chemistry)

4. ABBREVIATIONS
RDA = Recommended Dietary Allowance
AI = Adequate Intake
UL = Upper Limit
DDI = Daily Dietary Intake
DRI = Dietary Reference Intakes
MAL = Maximum Acceptable Limit
SAM = Standard Addition Method
AA = Atomic Absorption
FAAS = Flame Atomic Absorption Spectroscopy
HCL = Hollow Cathode Lamp
MIBK = Methyl isobutyl ketone
APDC = Ammonium pyrrolidine dithiocarbamate
ND = Non Detectable
PMT = Photomultiplier tubes
LPG = Liquefied petroleum gas
ppm = Parts per million
Cu = Copper
Cr = Chromium
Pb = Lead
Ni = Nickel
Na = Sodium
Fe = Iron
Ca = Calcium
Cd = Cadmium
UL = The maximum level of daily nutrient intake that is likely to pose
no risk of adverse effects. Unless otherwise specified, the UL
represents total intake from food, water, and supplements.
ND = Non detectable due to lack of data of adverse effects in this age
group and concern with regard to lack of ability to handle excess
amounts. Source of intake should be from food only to prevent high
levels of intake.

5. Introduction
Tea is an aromatic beverage commonly prepared by pouring hot or boiling
water over cured leaves of the tea plant, Camellia sinensis. After water, tea is
the most widely consumed beverage in the world. It has a cooling, slightly
bitter, and astringent flavour that many people enjoy
Tea originated in China as a medicinal drink. It was first introduced to
Portuguese priests and merchants in China during the 16th century. Drinking tea
became popular in Britain during the 17th century. The British introduced it to
India, in order to compete with the Chinese monopoly on the product
Tea has long been promoted for having a variety of positive health benefits.
Recent studies suggest that green tea may help reduce the risk of cardiovascular
disease and some forms of cancer, promote oral health, reduce blood pressure,
help with weight control, improve antibacterial and antivirasic activity, provide
protection from solar ultraviolet light, and increase bone mineral density. Green
tea is also said to have "anti-fibrotic properties, and neuroprotective power."
Additional research is needed to "fully understand its contributions to human
health, and advise its regular consumption in Western diets."
Tea catechins have known anti-inflammatory and neuroprotective properties,
help regulate food intake, and have an affinity for cannabinoid receptors, which
may suppress pain and nausea and provide calming effects.
Consumption of green tea is associated with a lower risk of diseases that cause
functional disability, such as “stroke, cognitive impairment, and osteoporosis”
in the elderly.
Tea contains L-theanine, an amino acid whose consumption is mildly associated
with a calm but alert and focused, relatively productive (alpha wave-dominant)
mental state in humans. This mental state is also common to meditative practice.

6. The phrase herbal tea usually refers to infusions of fruit or herbs made
without the tea plant, such as rosehip tea, chamomile tea, or rooibos tea.
Alternative phrases for this are tisane or herbal infusion, both bearing an
implied contrast with "tea" as it is construed here.
Health effects of Tea
Tea contains a large number of possibly bioactive chemicals, including
flavonoids, amino acids, vitamins, caffeine and several polysaccharides,
and a variety of health effects have been proposed and investigated. It has
been suggested that green and black tea may protect against cancer, though
the catechins found in green tea are thought to be more effective in
preventing certain obesity-related cancers such as liver and colorectal
cancer, while both green and black teas may protect against cardiovascular
disease
Negative effects of tea drinking are centered around the consumption of
sugar used to sweeten the tea. Those who consume very large quantities of
brick tea may experience fluorosis.
Numerous recent epidemiological studies have been conducted to
investigate the effects of green tea consumption on the incidence of human
cancers. These studies suggest significant protective effects of green tea
against oral, pharyngeal, oesophageal, prostate, digestive, urinary tract,
pancreatic, bladder, skin, lung, colon, breast, and liver cancers, and lower
risk for cancer metastasis and recurrence.

7. Review of Literature
Başgel et al (2005) reported the daily mineral intake by consuming herbal
teas for a 70 kg person per day are 500 mg Ca, 300 mg Mg, 15 mg Fe, 5
mg Al, 2.8 mg Mn, 15 mg Zn, 2.5 mg Cu, 1.6 mg Sr, 1.1 mg Ba, 0.025 mg
Ni, 0.05-0.2mg Cr, 0.04 mg Co, 0.415 mg Pb and 0.057 mg Cd. This
shows that the amounts of heavy metals are presence in herbal tea.
Most of slimming tea products consists of tea (Camellia sinensis) which is
either green tea or black tea. Ansari et al (2007) stated that tea (Camellia
sinensis) is the most popular beverage in the world and contains several
essential nutrients, which are beneficial for human health. The
contamination of tea leaves by heavy metals may pose a serious threat to
human, because they are not biodegradable and remain in environment and
pass to food chain. The concentration of heavy metals of Cd, Pb, Ni, and
Al and macro elements of Fe, Zn, Cu and Mn were determined by atomic
absorption spectrometry on 30 samples of black tea cultivated in Iran and
compared with the results for 30 samples of imported black tea in 2006.
The results of analysis showed that the mean level of Al was 699.2±172.7
mg/kg for Iranian and 388.3±98.3 mg/kg for imported black tea. However,
the values for Cd, Pb, and Ni were non-detectable. The most abundant
nutritive metal was manganese with 155.2-214.2 mg/kg and 96.7-332.9
mg/kg in Iranian and imported black tea, respectively.

8. RANK OF TEA PRODUCTION IN DIFFERENT
COUNTRIES
Rank Country 2008 2009 2010 2011
1 China 1,274,984 1,375,780 1,467,467 1,640,310
2
India 987,000 972,700 991,180 1,063,500
3
Kenya 345,800 314,100 399,000 377,912
4
Sri
Lanka
318,700 290,000 282,300 327,500
5
Turkey 198,046 198,601 235,000 221,600
6
Vietnam 173,500 185,700 198,466 206,600
7
Iran 165,717 165,717 165,717 162,517
8 Indonesia 150,851 146,440 150,000 142,400
9 Argentina 80,142 71,715 88,574 96,572
10
Japan 96,500 86,000 85,000 82,100
Total World 4,211,397 4,242,280 4,518,060 4,321,011

9. Health effects of nickel
Nickel is a compound that occurs in the environment only at very low
levels. Humans use nickel for many different applications. The most
common application of nickel is the use as an ingredient of steal and
other metal products. It can be found in common metal products such
as jewelry.
Food stuffs naturally contain small amounts of nickel. Chocolate and
fats are known to contain severely high quantities. Nickel uptake will
boost when people eat large quantities of vegetables from polluted
soils. Plants are known to accumulate nickel and as a result the nickel
uptake from vegetables will be eminent. Smokers have a higher nickel
uptake through their lungs. Finally, nickel can be found in detergents.
Humans may be exposed to nickel by breathing air, drinking water,
eating food,Beverages or smoking cigarettes. Skin contact with
nickel-contaminated soil or water may also result in nickel exposure.
In small quantities nickel is essential, but when the uptake is too high
it can be a danger to human health.
An uptake of too large quantities of nickel has the following
consequences:
- Higher chances of development of lung cancer, nose cancer, larynx
cancer and prostate cancer
- Sickness and dizziness after exposure to nickel gas
- Lung embolism
- Respiratory failure
- Birth defects
- Asthma and chronic bronchitis
- Allergic reactions such as skin rashes, mainly from jewelry
- Heart disorders
Nickel fumes are respiratory irritants and may cause pneumonitis.
Exposure to nickel and its compounds may result in the development
of a dermatitis known as “nickel itch” in sensitized individuals. The
first symptom is usually itching, which occurs up to 7 days before
skin eruption occurs. The primary skin eruption is erythematous, or

10. follicular, which may be followed by skin ulceration. Nickel
sensitivity, once acquired, appears to persist indefinitely.
Carcinogenicity- Nickel and certain nickel compounds have been
listed by the National Toxicology Program (NTP) as being reasonably
anticipated to be carcinogens. The International Agency for Research
on Cancer (IARC) has listed nickel compounds within group 1 (there
is sufficient evidence for carcinogenicity in humans) and nickel
within group 2B (agents which are possibly carcinogenic to humans).
OSHA does not regulate nickel as a carcinogen. Nickel is on the
ACGIH Notice of Intended Changes as a Category A1, confirmed
human carcinogen.

11. Health effects of chromium
People can be exposed to chromium through breathing, eating or
drinking and through skin contact with chromium or chromium
compounds. The level of chromium in air and water is generally low.
In drinking water the level of chromium is usually low as well, but
contaminated well water may contain the dangerous chromium(IV);
hexavalent chromium. For most people eating food that contains
chromium(III) is the main route of chromium uptake, as
chromium(III) occurs naturally in many vegetables, fruits, meats,
yeasts and grains. Various ways of food preparation and storage may
alter the chromium contents of food. When food in stores in steel
tanks or cans chromium concentrations may rise.
Chromium(III) is an essential nutrient for humans and shortages may
cause heart conditions, disruptions of metabolisms and diabetes. But
the uptake of too much chromium(III) can cause health effects as
well, for instance skin rashes.
Chromium(VI) is a danger to human health, mainly for people who
work in the steel and textile industry. People who smoke tobacco also
have a higher chance of exposure to chromium.
Chromium(VI) is known to cause various health effects. When it is a
compound in leather products, it can cause allergic reactions, such as
skin rash. After breathing it in chromium(VI) can cause nose
irritations and nosebleeds.
Other health problems that are caused by chromium(VI) are:
- Skin rashes
- Upset stomachs and ulcers
- Respiratory problems
- Weakened immune systems
- Kidney and liver damage
- Alteration of genetic material
- Lung cancer
- Death
The health hazards associated with exposure to chromium are
dependent on its oxidation state. The metal form (chromium as it

12. exists in this product) is of low toxicity. The hexavalent form is toxic.
Adverse effects of the hexavalent form on the skin may include
ulcerations, dermatitis, and allergic skin reactions. Inhalation of
hexavalent chromium compounds can result in ulceration and
perforation of the mucous membranes of the nasal septum, irritation
of the pharynx and larynx, asthmatic bronchitis, bronchospasms and
edema. Respiratory symptoms may include coughing and wheezing,
shortness of breath, and nasal itch.
Carcinogenicity- Chromium and most trivalent chromium compounds
have been listed by the National Toxicology Program (NTP) and
International Agency for Research on Cancer (IARC) as having
inadequate evidence for carcinogenicity in experimental animals.
According to NTP, there is sufficient evidence for carcinogenicity in
experimental animals for the following hexavalent chromium
compounds; calcium chromate, chromium trioxide, lead chromate,
strontium chromate,and zinc chromate.

13. Health effects of copper
Copper can be found in many kinds of food, in drinking water and in
air. Because of that we absorb eminent quantities of copper each day
by eating, drinking and breathing. The absorption of copper is
necessary, because copper is a trace element that is essential for
human health. Although humans can handle proportionally large
concentrations of copper, too much copper can still cause eminent
health problems.
Copper concentrations in air are usually quite low, so that exposure to
copper through breathing is negligible. But people that live near
smelters that process copper ore into metal, do experience this kind of
exposure.
People that live in houses that still have copper plumbing are exposed
to higher levels of copper than most people, because copper is
released into their drinking water through corrosion of pipes.
Occupational exposure to copper often occurs. In the working
environment, copper contagion can lead to a flu-like condition known
as metal fever. This condition will pass after two days and is caused
by over sensitivity.
Long-term exposure to copper can cause irritation of the nose, mouth
and eyes and it causes headaches, stomachaches, dizziness, vomiting
and diarrhea. Intentionally high uptakes of copper may cause liver and
kidney damage and even death. Whether copper is carcinogenic has
not been determined yet.
There are scientific articles that indicate a link between long-term
exposure to high concentrations of copper and a decline in
intelligence with young adolescents. Whether this should be of
concern is a topic for further investigation.
Industrial exposure to copper fumes, dusts, or mists may result in
metal fume fever with atrophic changes in nasal mucous membranes.
Chronic copper poisoning results in Wilson’s Disease, characterized
by a hepatic cirrhosis, brain damage, demyelization, renal disease, and
copper deposition in the cornea.

14. Health effects of lead
Lead is a soft metal that has known many applications over the years.
It has been used widely since 5000 BC for application in metal
products, cables and pipelines, but also in paints and pesticides. Lead
is one out of four metals that have the most damaging effects on
human health. It can enter the human body through uptake of food
(65%), water (20%) and air (15%).
Foods such as fruit, vegetables, meats, grains, seafood, soft drinks and
wine may contain significant amounts of lead. Cigarette smoke also
contains small amounts of lead.
Lead can enter (drinking) water through corrosion of pipes. This is
more likely to happen when the water is slightly acidic. That is why
public water treatment systems are now required to carry out pH-
adjustments in water that will serve drinking purposes.
For as far as we know, lead fulfils no essential function in the human
body, it can merely do harm after uptake from food, air or water.
Lead can cause several unwanted effects, such as:
- Disruption of the biosynthesis of haemoglobin and anaemia
- A rise in blood pressure
- Kidney damage
- Miscarriages and subtle abortions
- Disruption of nervous systems
- Brain damage
- Declined fertility of men through sperm damage
- Diminished learning abilities of children
- Behavioural disruptions of children, such as aggression, impulsive
behavior and hyperactivity
Lead can enter a foetus through the placenta of the mother. Because
of this it can cause serious damage to the nervous system and the
brains of unborn children

15. Health effects of cadmium
Human uptake of cadmium takes place mainly through food.
Foodstuffs that are rich in cadmium can greatly increase the cadmium
concentration in human bodies. Examples are liver, mushrooms,
shellfish, mussels, cocoa powder and dried seaweed.
An exposure to significantly higher cadmium levels occurs when
people smoke. Tobacco smoke transports cadmium into the lungs.
Blood will transport it through the rest of the body where it can
increase effects by potentiating cadmium that is already present from
cadmium-rich food.
Other high exposures can occur with people who live near hazardous
waste sites or factories that release cadmium into the air and people
that work in the metal refinery industry. When people breathe in
cadmium it can severely damage the lungs. This may even cause
death.
Cadmium is first transported to the liver through the blood. There, it
is bond to proteins to form complexes that are transported to the
kidneys. Cadmium accumulates in kidneys, where it damages filtering
mechanisms. This causes the excretion of essential proteins and
sugars from the body and further kidney damage. It takes a very long
time before cadmium that has accumulated in kidneys is excreted
from a human body.
Other health effects that can be caused by cadmium are:
- Diarrhoea, stomach pains and severe vomiting
- Bone fracture
- Reproductive failure and possibly even infertility
- Damage to the central nervous system
- Damage to the immune system
- Psychological disorders
- Possibly DNA damage or cancer development

16. Health effects of calcium
Calcium is the most abundand metal in the human body: is the main
constituent of bones and theets and it has keys metabolic functions.
Calcium is sometimes referred to as lime. It is most commonly found
in milk and milk products, but also in vegetables, nuts and beans. It is
an essential component for the preservation of the human skeleton
and teeth. It also assists the functions of nerves and muscles. The use
of more than 2,5 grams of calcium per day without a medical
necessity can lead to the development of kidney stones and sclerosis
of kidneys and blood vessels.
A lack of calcium is one of the main causes of osteoporosis.
Osteoporosis is a disease in which the bones become extremely
porous, are subject to fracture, and heal slowly, occurring especially
in women following menopause and often leading to curvature of the
spine from vertebral collapse.
Unlike most of the people think, there is an intense biological activity
inside our bones. They are being renewed constantly by new tissue
replacing the old one. During childhood and adolescence, there’s
more production of new tissue than destruction of the old one, but at
some point, somewhere around the 30 or 35 years of age, the process
is inverted and we start to loose more tissue than what we can replace.
In women the process is accelerated after the menopause (he period
marked by the natural and permanent cessation of menstruation,
occurring usually between the ages of 45 and 55); this is because their
bodies stop producing the hormone known as estrogen, one of which
functions is to preserve the osseous mass.
Evidence suggests that we need a daily intake of 1,000 milligrams of
calcium in order to preserve the osseous mass in normal conditions.
This is both for man and pre-menopausic women. The recommended
daily intake rises to 1,500 for menopausic woman.
The main calcium sources are the dairy products, but also nuts, some
green vegetables like spinach, and cauliflower, beans, lentils…
Calcium works together with magnesium to create new osseous mass.
Calcium should be taken together with magnesium in a 2:1 rate, that
is to say, if you ingest 1000 mg of calcium, you should also ingest
500 mg of magnesium. Some magnesium sources in the diet are

17. seafood, whole-grains, nuts, beans, wheat oats, seeds and green
vegetables.
Other important measures to prevent osteoporosis are:
• Doing regular exercise (at least three times a week)
• Taking adequate amounts of manganese, folic acid, vitamin B6,
vitamin B12, omega 3 (it aids calcium absorption and stimulates new
osseous mass production) and vitamin D (it aids calcium absorption in
the small intestine).
• Not abusing of sugar, saturated grease and animal proteins
• Not abusing of alcohol, caffeine, nor gaseous drinks
• Not smoking
Other triggers for osteoporosis are the hereditary factor and the stress.

18. EXPERIMENTAL
MATERIALS AND METHODS
Sample Collection
Tea samples were collected from Rajamandi, the main market of
Agra. Sampling was done at random from different retailers and
vendors of this market. A total of six (6) varieties broke bond taza,
dhadkan, patakha, razana, red lebel and tata tea were collected.
Sampling was done during four days in December 2013. The tea
samples were then analyzed for Cd, Cr, Cu, Ni, Pb, and Ca.
Sample Preparation
Took 1 gm of tea sample and digested in aqua-ragia. Then made upto
the mark in 100 ml measuring flask.
Sample treatment and analysis
All metal salts dissolved in tea are adsorbed on some materials
present as impurities in tea. Therefore, the sample should be digested
rigidly under controlled condition. Maintain constant sample volume,
acid strength and contact time. Use the least rigorous digestion
method to provide acceptable and consistent recovery compatible to
analytical method and metal being analyzed.
HNO3 DIGESTION
Transfer a 1gm of sample to a flask or a beaker and add 5ml conc.
HNO3. If the beaker used, partially cover it with a watch glass to
minimize contaminations. Take the container under a fume hood and
heat solely on a hot plate or burner to boiling and evaporate to
dryness. The solution at this state should be clear having a light
colour. If not continue heating and adding conc. HNO3 till the
digestion is complete i.e., a clear or light coloured solution is
obtained.

19. Remove the flask or beaker and cool for 10 min. wash down its and
watch glass cover with water and if necessary. Transfer filtrate to a
100 ml volumetric flask with 5ml portion of water adding this rinsings
to the vol. flask, dilute to mark and mix thoroughly .take portions of
the solution for required metal determinations.
HNO3-HCl
If the above solution has any ppt. or residue at 10ml of dilute HCl in
20ml of water per 100ml anticipated final volume. Heated for an
additional 20 minutes to dissolve the ppt or residue . Cool wash down
beaker wall and watch glass with water , filtered to remove insoluble
material and transfer filterate to a 100ml of volume flask with rinsing.
Alternatively, centrifuge . adjusted to volume and mixed thoroughly.
Apparatus
A Perkin-Elmer AAnalyst100 double beam atomic absorption
spectrophotometer (Perkin-Elmer corp., CT) was used at a slit width
of 0.7 nm, with hollow cathode lamps for mineral measurements by
FAAS. Samples were atomized for Cr, Cu, Cd, Ni, and Pb. All
analyses were performed in peak height mode to calculate absorbance
values.
SYSTRONICS Flame photometer 130 was used for the estimation of
Ca.
All solutions were prepared from analytical reagent grade reagents,
for e.g., Commercially available 1,000 μg/mL Cu [prepared from
Cu(NO3)2.3H2O in 0.5 M HNO3] were used. The water employed
for preparing the standards for calibration and dilutions was ultra pure
water with a specific resistivity of 18 m_ cm-1 obtained by filtering
double-distilled water immediately before use.
Calcium can be easily analysed by Flame Photometer. Standards can
be prepared as follows-
 Calcium – 1000 ppm
Dissolved 2.497 g CaCO3 in approx 300 ml glass distilled water and
added 10 ml conc. HCl diluted to 1 litre. For calibration 20, 40, 60, 80
and 100 ppm solutions were prepared from the stock solution.

20. INSTRUMENTATION
Introduction Atomic absorption spectroscopy
Atomic absorption is a very common technique for detecting metals
and metalloids in environmental samples. It is very reliable and
simple to use. Figure 1 shows which elements are commonly detected
through atomic absorption. The technique is based on the fact that
ground state metals absorb light at specific wavelenths. Metal ions in
a solution are converted to atomic state by means of a flame. Light of
the appropriate wavelength is supplied and the amount of light
absorbed can be measured against a standard curve.
In analytical chemistry the technique is used for determining the
concentration of a particular element (the analyte) in a sample to be
analyzed. AAS can be used to determine over 70 different elements in
solution or directly in solid samples used in pharmacology, biophysics
and toxicology research.
Atomic absorption spectroscopy was first used as an analytical
technique, and the underlying principles were established in the
second half of the 19th century by Robert Wilhelm Bunsen and
Gustav Robert Kirchhoff, both professors at the University of
Heidelberg, Germany.
The modern form of AAS was largely developed during the 1950s by
a team of Australian chemists. They were led by Sir Alan Walsh at
the Commonwealth Scientific and Industrial Research Organisation
(CSIRO), Division of Chemical Physics, in Melbourne, Australia.
Atomic absorption spectrometry has many uses in different areas of
chemistry such as:
• Clinical analysis: Analyzing metals in biological fluids and
tissues such as whole blood, plasma, urine, saliva, brain tissue, liver,
muscle tissue, semen
• Pharmaceuticals: In some pharmaceutical manufacturing
processes, minute quantities of a catalyst that remain in the final drug
product
• Water analysis: Analyzing water for its metal content.

21. Basic Principle
The technique of atomic absorption spectroscopy (AAS) requires a
liquid sample to be aspirated, aerosolized, and mixed with
combustible gases, such as acetylene and air or acetylene and nitrous
oxide. The mixture is ignited in a flame whose temperature ranges
from 2100 to 2800 oC.
During combustion, atoms of the element of interest in the sample are
reduced to free, unexcited ground state atoms, which absorb light at
characteristic wavelengths, as shown in figure 3.
Figure 3. Operation principle of an atomic absorption spectrometer.
The characteristic wavelengths are element specific and accurate to
0.01-0.1nm. To provide element specific wavelengths, a light beam
from a lamp whose cathode is made of the element being determined
is passed through the flame. A device such as photonmultiplier can
detect the amount of reduction of the light intensity due to absorption
by the analyte, and this can be directly related to the amount of the
element in the sample.
The technique makes use of absorption spectrometry to assess the
concentration of an analyte in a sample. It requires standards with
known analyte content to establish the relation between the measured
absorbance and the analyte concentration and relies therefore on the
Beer-Lambert Law.

22. Instrumentation Hardware
Figure; Flame absorbrion spectrometer with attached graphite
furnace.
Figure shows an atomic absorption spectrometer. This instrument in
particular is designed to operate either with a flame or with a graphite.
The graphite furnace is additionally equipped with an auto sampler.
In order to analyze a sample for its atomic constituents, it has to be
atomized. The atomizers most commonly used nowadays are flames
and electrothermal (graphite tube) atomizers. The atoms should then
be irradiated by optical radiation, and the radiation source could be an
element-specific line radiation source or a continuum radiation
source. The radiation then passes through a monochromator in order
to separate the element-specific radiation from any other radiation
emitted by the radiation source, which is finally measured by a
detector.
Flame atomic absorption hardware is divided into six fundamental
groups that have two major functions: generating atomic signals and
signal processing. Signal processing is a growing additional feature to
be integrated or externally fitted to the instrument. The instrument
parts are shown in figure

23. Figure . schematic of basic instrumental parts of atomic absorption
spectrometer
.
A cathode lamp (1), is a stable light source, which is necessary to emit
the sharp characteristic spectrum of the element to be determined. A
different cathode lamp is needed for each element, although there are
some lamps that can be used to determine three or four different
elements if the cathode contains all of them. Each time a lamp is
changed, proper alignment is needed in order to get as much light as
possible through the flame, where the analyte is being atomized, and
into the monochromator.

24. The atom cell (2), shown in figure , is the part with two major
functions: nebulization of sample solution into a fine aerosol solution,
and dissociation of the analyte elements into free gaseous ground state
form. Not all the analyte goes through the flame, part of it is disposed
as shown in the figure.
Figure . Atom cell.
As the sample passes through the flame, the beam of light passes
through it into the monochromator (3). The monochromator isolates
the specific spectrum line emitted by the light source through spectral
dispersion, and focuses it upon a photomultiplier detector (4), whose
function is to convert the light signal into an electrical signal.
The processing of electrical signal is fulfilled by a signal amplifier
(5). The signal could be displayed for readout (6), or further fed into a
data station (7) for printout by the requested format.

25. TABLE-I
Metal concentration in mg/L studied in Tea samples during
this project
Samples
Elements
Broke
bond
Taza
Dhadkan Patakha Razana Red
lebel
Tata
tea
UL
Copper 0.923 0.481 0.8083 0.7429 0.2392 0.735 < 1
Nickel 1.012 1.125 0.893 0.792 0.962 0.786 0.5- 1
Lead 1.151 0.755 0.958 0.835 0.899 0.650 < 2
Cadmium 0.080 0.029 0.122 0.046 0.051 0.084 0.1
Chromium 4.683 6.914 3.717 4.741 3.708 2.961 3
Calcium 70 70 68 66 60 66 100

26. Result and discussion
Table 1 presents the concentrations of metals found in the teas
considered. These contents agree with literature data reported by other
researchers. The maximum copper concentration was found in the
broke bond taza sample and the lowest copper concentration was in
red lebel. However, these values were found to be in accordance with
UL approved by WHO.
There was not much variation in the concentration of nickel in all
samples. The concentration was safe according to WHO.
Although, the highest lead concentration was found in Broke Bond
Taza but it was not too high to consider.
But ofcourse, chromium level was found to be extremely high in
Dhadkan sample.
The calcium level was low as recommended by WHO.
The DDI of the studied metals are tabulated here.

27. TABLE-I
Nutrient Life Stage
Group
RDA/AI
(μg/d)
UL
(μg/d)
Copper
Males
14-18 y
19-50 y
Females
14-18 y
19-50 y
Pregnancy
19-30 y
31-50 y
Lactation
19-30 y
31-50 y
890
900
890
900
1000
1000
1300
1300
8,000
10,000
8,000
10,000
10,000
10,000
10,000
10,000

28. TABLE-II
Nutrient Life Stage
Group
RDA/AI
(μg/d)
UL
(μg/d)
Chromium
Males
14-18 y
19-50 y
Females
14-18 y
19-50 y
Pregnancy
19-30 y
31-50 y
Lactation
19-30 y
31-50 y
35
35
24
25
30
30
45
45
ND
ND
ND
ND
ND
ND
ND
ND

30. TABLE-III
Nutrient Life Stage
Group
RDA/AI
(mg/d)
UL
(mg/d)
Calcium
Males
14-18 y
19-50 y
Females
14-18 y
19-50 y
Pregnancy
19-30 y
31-50 y
Lactation
19-30 y
31-50 y
1,300
1,000
1,300
1,000
1,000
1,000
1,000
1,000
2,500
2,500
2,500
2,500
2,500
2,500
2,500
2,500

31. TABLE-IV
Nutrient Life Stage
Group
RDA/AI
(mg/d)
UL
(mg/d)
Nickel
Males
14-18 y
19-50 y
Females
14-18 y
19-50 y
Pregnancy
19-30 y
31-50 y
Lactation
19-30 y
31-50 y
ND
ND
ND
ND
ND
ND
ND
ND
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0

32. TABLE-IV
LEAD
For Whom Amount Known To
Cause Health Problems
(μg/d)
FDA’s Recommended Safe
Daily Diet Lead Intakes
(μg/d)
For children under age 6 60 6
For children 7 and up 150 15
For Adults 750 75

33. Conclusions
Tea is the most common beverage used in everyday life by everyone.
It must follow the UL recommended by WHO for heavy metals. In
present study six tea samples (Broke Bond Taza, Dhadkan, Patakha,
Razana, Red lebel and Tata tea) were analysed for Cu, Ni, Pb, Cd, Cr
and Ca. on the basis of tea analysis report for the elements studied, we
have concluded that the most of the tea samples were under DL and
PL. therefore the samples were found to be fit to consume. However
some samples were found to be polluted and are therefore completely
unfit to consume.
Tea should not consume in high quantity because chromium was
found to be crossing the UL proposed by WHO.

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