Appropriate Instruments & techniques for Complying with Air Quality Standards

APPROPRIATE INSTRUMENTS AND
TECHNIQUES FOR COMPLYING
WITH NEW AMBIENT AIR QUALITY
MONITORING STANDARDS
Dr. S. K. Bhargava,
Chairman,
State Expert Appraisal Committee, U. P.
&
Former Deputy Director & Head,
Environmental Monitoring Section,
Indian Institute of Toxicology Research,Lucknow

The presence in outdoor atmosphere, of one or
more contaminants such as fumes, dust, gases,
mist, grit, odor, smoke, smog or vapors in
considerable quantities and of duration which is
injurious to human, animal or plant life of which
unreasonably interferes with comfortable
enjoyment of life and property.”
How Do We Define the Air Pollution ?

Natural Sources
Volcanic Eruptions
Forest Fires
Natural Decays
Marsh Gases
Cosmic Dusts
Soil Debris
Pollen Grains
Fungal Spores
Anthropogenic
Sources
Increase in Population
Vehicular Pollution
Deforestation
Burning of Fossil
Fuels
Rapid Industrialization
Agricultural Activities
Wars
Sources of Pollution

Health Effects
Pollutants Health Effects
SPM & RSPM Respiratory diseases, reduce visibility
SO2 Irritation of eyes, respiratory system, increased
mucus production, cough and shortness of breath.
NOX Irritation of pulmonary tract affecting functioning of
lungs.
CO Reduction in oxygen-carrying capacity of blood,
prone to cardiovascular diseases
Hydrocarbons Lung cancer, irritation of mucus membrane.
Pb Cumulative poison, impairment of central nervous
system, disruption of pathways of haem
synthesis,increase in d-aminolevulinic acid
dehydratase activity in red cells/or elevated levels
of erythrocyte protoporphyrin
Benzene Leukaemia, Chromosomal damage

Pollutants Health Effects
Ammonia Eye, Nose, Throat irritation, Dyspnea,
Bronchospasm, Chest Pain, Pulmonary edema,
Pink frothy sputum,Skin burns, vesiculation
Nickel Head verti, nausea, vomit, epigastric, substernal
pain, cough, hypernea
Arsenic Ulceration of nasal septum, gastrointestinal
disturbances, hyperpigmentation of skin
Benjo(a)Pyrene Carcinogenic
Health Effects

Penetration of RSPM in Respiratory
System

Primary and Secondary Pollutants
 Primary pollutant is an air pollutant emitted
directly from a source.
 Secondary pollutant is not directly emitted as
such, but forms when other pollutants (primary
pollutants) react in the atmosphere.
Examples of a secondary pollutant include ozone,
which is formed when hydrocarbons (HC) and
nitrogen oxides (NOx) combine in the presence of
sunlight; NO2, which is formed as NO combines
with oxygen in the air; and acid rain, which is
formed when sulfur dioxide or nitrogen oxides react
with water.

Objective of Air Monitoring
 To assess health hazards and potential damage to
property;
 To determine the background pollution level for
application in industrial zoning, town planning or
location of sites for certain types of industries
requiring stringent air quality criteria;
 To determine the degree of air pollution control
required for existing industries;
 To identify industrial and other source of pollution;
Conti…….

 To collect data for formulating and testing air
pollution models;
 To identify and control pollution from vehicular
emission;
 To monitor the criteria pollutants depending on
the locations;
 To determine present air quality status and
trend;
 To control and regulate pollution from
industries and other sources to meet the air
quality standards.

Guidelines for carrying out Ambient Air
Quality Monitoring developed by CPCB
 Site selection criteria;
 Quality assurance and quality control in air
quality monitoring;
 Type of pollutants to be monitored in a city;
 Frequency and duration of monitoring;
 Data reporting and compilation procedures;
 Measurement methods of various air pollutants
etc.

Site Selection Criteria
 The site should be representative of the location
being assessed. It should not be unduly
influenced by immediate surroundings unless
those influences are specifically being
measured, for example, near a busy road, a
factory stack or a dusty quarry.
 The site should not be subject to flooding, and
the site classification or situation should not
change over time.

National Ambient Air Quality Standard
Pollutants
Pre November 2010
 SO2
 NOx
 SPM
 PM10
 Pb
 Ammonia
 CO
Post November 2010
 SO2
 NOx
 PM10
 PM2.5
 O3
 Pb
 Carbon Monoxide
 Ammonia
 Benzene
 Benzo(a)pyrene
 Arsenic
 Nickel

National Ambient Air Quality Standard
Area
 Industrial, Residential, Rural& other Areas
 Ecologically Sensitive Area

Rotameter and Floats
Gas Flow
Rotameter
Floats

Sampling Device
Any gas sampling equipment has three
essential component
 Suction device
 Metering device
 Trapping device to retain the contaminants
 Equipment with two are even three of the
above component in combination have been
designed

Method Prescribed in the standard are:
SO2
 Improved West and Gaeke
 Ultaviolet Florosence
NOx
 Jacob & Hochheiser (Na-Arsenite)
 Chemiluminescence's
PM10 & PM 2.5
 Gravimetric
 TOEM
 Beta attenuation
O3
 UV Photometric
 Chemical Method
Pb
 AAS/ICP method after sampling on EPM 2000 or equivalent


CO
 Non dispersive infrared spectroscopy (NDIR)
NH3
 Indophenols Blue Method
Benzene
 Gas Chromatography based continuous analyzer
 Adsorption and desorption followed by GC
Benzo (a) pyrene particulate phase only
 Solvent Extraction followed by HPLC/GC
Arsenic & Nickel

Types of Sampling
Spot sampling Batch Sampling Baseline Sampling
It is for short duration It is for long duration
(usually for 24 hours)
It is carried out to
determine the quality of
ambient for 1-hour and
24 hour.‑
Its duration varies from
less than 30 minutes to
several hours.
Batch sampling may
be carried out by the
chemical absorption or
filtration of measured
air volumes
sequentially in time.
During monitoring there
should not be any
construction or dust
generating activities in
the vicinity of the
monitoring stations.
It is useful for the random
checking of pollution at
any point due to some
local source.

Particulate matter which is very small ( less than 10 µm)
remain suspended in the air for a periods of time and easily
inhaled into the deep lungs. Increased death (mortality) and
diseases (morbidity). Currently PM10
have been identifying
death effects associated with environmental levels of PM10
is significant issue.
Particulate Matter
A. Suspended Particulate Matter (<100 µm)
B. Respirable Suspended Particulate Matter (<10 µm)
C. Fine Particles (<2.5 µm).
Particulate Matter is the term used for a mixture of
solid particles and liquid droplets found in the air.
Coarse particles larger than 10 µm is known as
SPM (Suspended Particulate Matter).

Application and Limitation for Sampling
Airborne Particulate Matter
 As per the new notification it measures PM10,
PM2.5 .
 A known volume of air is passed through
initially weighted glass fibre filter paper (GF/A)
of size 8” x 10”.
 Centrifugal force acts on the dust particles to
separate it into two parts.
 Below 10 µm collected on filter paper.
 Particle above 10 µm collected in cyclone cap.
 The difference in initial and final weight of filter
paper and cyclone cap used in calculation to
express the result in µg/m3
.

Instructions for Measurement of Particulate
Matter
Conditioning of Filter Paper:
 Both blank and sampled filters shall be conditioned at
20-250
C and relative humidity below 50% for 16 hrs.
prior to weighing.
Sampling:
 Use fresh carbon brush after every 48 hrs of sampling
or use brushless sampler.
Handling:
 Do not bend or fold the filter before collection of
samples.
Transport and Storage:
 Filter papers can be transported in filter paper box.

 RSPM sampling by Respirable Dust
Sampler as per IS 5182 Part 32 involves the
principle of filtering a known volume of air
through a glass fiber filter paper of known
weight at an average speed of 1.0-1.5 m3
air/min.
 RSPM (µg/m3
) = (W2-W1) *106
___________________________
Volume of air sampled
Where W1 is initial weight (g) and W2 is
final weight (g) of the filter paper
Methods for Sampling Airborne Particulate
Matter
PM10

APM 550 for PM10 & 2.5
 The APM 550 uses a brush-less pump
with a low noise.
 Same instrument can be used for PM10
and PM2.5 sampling.
 Lower sampling rate of 1m3
/hour reduces
filter choking even in areas having high
FPM levels.
 Critical Orifice maintains constant
sampling rate of 1m3
/hour.
 Compact and portable for convenient field
operation.

Beta Ray Attenuation Measurement
•This method provides a simple determination of concentration in units of
milligrams or micrograms of particulate per cubic meter of air.
•A small 14
C (Carbon 14) element emits a constant source of high-energy
electrons known as beta particles.
•These beta particles are detected and counted by a sensitive scintillation
detector.
•An external pump pulls a measured amount of dust-laden air through a filter
tape.
•After the filter tape is loaded with ambient dust, it is automatically placed
between the source and the detector thereby causing an attenuation of the
beta particle signal.
•The degree of attenuation of the beta particle signal is used to determine the
mass concentration of particulate matter on the filter tape, and hence the
volumetric concentration of particulate matter in ambient air.

Particulate Monitor Flow diagram
Hourly tape spots

Step by step test instruction to be‑
followed for Gaseous Sampling
Install the RDS at a height of 1.5 m.
Switch on the instrument,
Adjust the timer reading for required hours of
sampling, Flow rate to be adjusted 0.5 litre per
minute at the initial stage. Note the initial and final
manometer readings,
Fill the impinger with 10 ml by the absorbing
solution,
After 4 / 8 hours of operation transfer the media to
plastic bottle (60 ml) and then analyse the sample.

SO2
 Improved West and Gaeke
 Ultraviolet Florescence
Standard: µg/m3
Industrial, Residential, Ecologically Sensitive
Rural& other Areas Areas
Annual Average 50 20
24 hr Average 80 80

SO2 Source
 Natural process 67%
 Volcanoes
 Manmade 33%
 Fuel combustion
 Coal
 Biofuel
 Diesel
 Removal of Sox from fuel gases
 Removal of Sulphur from fuel burning and use of low
sulphur fuel
 Sulphur can be remove by using chemical scrubber in
which gases passes through lime stone.

SO2 by Improved West and Gaeke
Method
Principle
 Sulphur Dioxide is absorbed from air in a
solution of Sodium/Potassium Tetra
Chloromercurate (TCM)
 Ambient SO2 react with it and forms a stable
dichlorosulphitomercurate complex
 The amount of SO2 then estimated by colour
produced when p-rosaalinie is added to the
solution.

Range and Sensitivity
This method can measure concentration
over an approximate range of 0.005 to
5.0 ppm with an accuracy of ±10%
(including sampling and analysis at the
lower end of the range and ±5% at the
upper end with the precision of about
2%.

Take the 10 ml portion of Sample.
Then add 2 ml sulphamic acid + 2 ml of formaldehyde + 1 ml
p-rosaniline.
After 20 min., read the absorbance at 560 nm in a
spectrometer with the blank as reference.
Methodology for Analysis of SO2
(West & Gaeke Method)

Reaction Mechanism
 HgCl4
-2
+SO2+ H2O =HgCl2SO3
-2
+2H+2Cl-
 SO2+H2O+HCHO=HOCH2-SO3H
C6H4-NH3
 NH3-C6H4-C-C6H4-NH3 + HOCH2-SO3H= p-rosaline methyle
Cl sulphonic
acid

Equipments used
 A midget impinger contains absorbing
solution
 A pump suitable to desire flow rate of
0.2-1.0 lpm
 A volume meter with thermometer,
manometer and timer.

Chemicals Required
Absorbent
 0.1 M Sodium –tetra chloromercurate (Na2HgCl4) (27.2 g
HgCl2 and 11.7 g NaCl in 1000 ml D.W.)
Rosaaniline hydrochloride(0.04%)
 0.2 gm of dye in 100 ml of DDW, after 48 hrs filter the
solution (This is stable for three month if kept in dark)---(A)
 Take 20 ml of (A) in 100 ml flask add 6ml conc. HCl and
after five min fill up to the mark with DDW. (stable 2 week if
refrigerated)
Formaldehyde (0.2%)
 5ml of 40% in 1000ml DDW

Standard Solution
 Calibration-0.0123 N Sodium Metabisulphite
(1ml=150 µl SO2)
(Dissolve 640 mg of metabisulphite (65%.5)as SO2 in 1 liter of DDW
standardized with iodine using starch as indicator)
 0.01 Iodine-
(Dissolve 12.69 of resublimed iodine in 25 ml of solution made with
15 gm iodate-free KI, Dilute to 1 liter, pipette 100 into 1000ml flask,
fill to mark with 1.5%KI, check the normality by standard
thiosulphate)

Standardization of metabisulphie
Follow the following steps:
 Standardize sodium thiosulphate with
potassium dichromate
 Standardize iodine with standard thiosulphate
 Standardize metabisulphite with standard
iodine and finally make the solution of
0.0123N
 Dilute 2ml of this in 100 ml with absorbing
reagent, this is equivalent to 3µl of SO2 per ml

Procedure
 10 ml absorbing in midget impinger
 Bubble known volume of air through any gas
collecting device. (This is stable up to three days)
 Adjust volume to 10 ml with D.W. (If any
evaporation loss occurs)
 Add 1ml each of complexing reagent and mix.
 Prepared a blank in same manner.
 After 20 min read absorbance at 560 nm.
 Calculate ppm or µg/m3
of SO2. 1ppm=1µl of
SO2 /liter of air

SO2
Ultraviolet Fluorescent
 Sulphur dioxide absorbs UV energy at
190nm-230nm free from interference and
come to the exited state, producing
fluorescence, which is measured by PMT.
 The fluorescence reaction impinging up on
the PMT is directly proportional to to the
concentration of SO2.

Optical measurement theory
Exhaust air is scrubbed with a charcoal scrubber to eliminate Hydrocarbons and
SO2. This air is then ideal for use in the hydrocarbon kicker to remove
hydrocarbons from sample air.
Sample
Inlet
SO2 + photon
Particulate
Filter
Fluorescence
Cell
PMT
Microprocessor
SO2 Outputs
exhaust
SO2 *
Hydrocarbon
kicker
Optical
filter
UV lamp
SO2 + UV
SO2 Analyzer Flow diagram

Oxides of Nitrogen (as NO2)
 Jacob & Hochheiser (Na-Arsenite)
Standard: (µg/m3
)
24 hr Average 80 80

Source
 Combustion of Coal, Oil, Natural gas and
Gasoline
 Average residence time in atmosphere is 4
days.
 At traffic rush time (6-8am) level of NO
increases.
 At mid morning level of NO2 increases due
to conversion of NO to NO2 by UV rays.

Jacob & Hochheiser (Na-Arsenite)
Principle
Nitrogen oxides as nitrogen dioxide are
collected by bubbling air through a sodium
hydroxide solution to form a stable solution of
sodium nitrite. The nitrite ion produced during
sampling is determined colorimetrically by
reacting the exposed absorbing reagent with
phosphoric acid, sulphanilam-ide and N
(1 napthyl) ethylenediamine dihydrochloride at‑
540nm

Range
 Range of the method is 20-740 µg/m3
(0.01 to 0.4
ppm) nitrogen dioxide in a 50 ml absorbing reagent
with a sampling rate of 200ml/min for 24 hr.
Reagents
 Absorbing reagent
(4.0gm NaOH + 1 gm sodium arsenite in 1000 ml D.W.)
 Sulphanilamide: 20gm in700ml D.W.
 NEDA: 0.5 gm of N (1-Napthyle) ethylene diamine
dihydrochloride

Equipment used
 Respirable Dust Sampler along with
gaseous attachment. Gaseous attachment
contains 4 (2 for SO2 and 2 for NOX) midget
impingers containing the absorbing
solution.
 Flow rate of gas in the midget impinger is
to be adjusted through manometer of the
gaseous attachment

Methodology for Analysis of NOx
Pipette 10 ml of the collected sample into a test tube.
Add 1 ml of H2O2, 10.0 of sulphanilamide solution and 1.4
ml of NEDA solution with thorough mixing after the
addition of each reagent.
After a 10-minute colour development interval, measure‑
the absorbance at 540 nm against the blank. Read µg
NO2 /ml from the standard curve.

Calculation
For calibration the amount of Potassium/Sodium Nitrate used can be
calculated:
G=(1.500/A)x100
Where:
G=Amount of Sodium Nitrate
1.500=Gravimetric Factor
A=Assay, percent
Mass NO2 in µg/m3
= (µg NO2/ml)/(V x 0.82)
Where: V=Volume of Air Sampled

NOx by Chemiluminescence's
 Emission of light from electrically exited
species due to the chemical reaction.
 NO+O3=NO2
*
+ O2
 NO2
*
=NO2+hv
 In this process light energy produce is directly
proportional to the NO concentration.
 NO is associated with NO2 therefore it is
necessary to convert NO2 to NO before
analysis

 Sample air is drawn into the reaction cell via two separate
(alternating) channels the NO and NOX. The NOX
channel travels through a delay coil enabling the same
sample of air to be sampled for NO, NO2 and NOX.
 The NOX channel passes through an NO2 to NO
converter, NO2 is converted to NO
 Sample air (NO & NOX channels) enter the
measurement cell where NO reacts
 with Ozone in the following reaction
 NO + O3 -> NO2* + O2
 Equation 1 Chemiluminescence reaction
Chemiluminescence

 This reaction releases energy in the form of Chemiluminescence
radiation (1100nm), which is filtered by the optical band pass filter
and detected by the Photomultiplier tube (PMT)
 The level of Chemiluminescence detected is directly proportionally to
the NO in sample
 NO2 is calculated by subtracting the NO measurement from NOX
measurement
 NOX = NO + NO2 or NO2 = NOX – NO
Sample
Inlet
NO + photon
3-way
solenoid valve
Particulate
Filter
Molycon
Ozone
Generator
Reaction
Cell
PMT
Microprocessor
NO,NO2,NOx
Outputs
exhaust
room air
Permeation
Dryer
NO2 NO
NO + O3 NO2 *
NOx Analyzer Flow diagram

Ammonia (NH3)
 Indophenols Blue Method
Standard: (µg/m3
)
Annual Average: 100 100
24 hr. Average 400 400

Principle
• Ammonia in the atmosphere is collected by
bubbling of measured amount of air through a
dilute solution of sulfuric acid to form
ammonium sulphate.
• The ammonium sulfate formed in the sample
is analysed colorimetric by reaction with
phenol and alkaline sodium hypochlorite to
produces Indophenols a blue dye.
• Sodium nitropruside accelerated the reaction
as an catalyst.

Range & Sensitivity
 With a sampling rate of 1-2 lit/mina conc.
range of 200-700µg/m3
. of air may be
determine with the sampling time of one hr.
 The limit of detection of the analysis is
0.02µNH3/ml.

Reagents
Ammonia free D.D.W.
Absorbing Solution (0.1 N)
(2.3 ml of conc. H2SO4(18M) in 1lit.DDW.)
Sodium Nitropruside:
(2g in 100ml of DDW)
(Stable for two months in refrigerator)
Sodium Hydroxide(6.75M)
(270g in 1lit.)

Buffer:
 50g Na3PO4.12H2O in and 74ml of 6.75 NaOH in DDW.
Working Hypochloride:
 Mix 30ml of 0.1NSodium hypochloride+30ml of 6.75 M
NaOH in 100ml DDW.
Working Phenol:
 20ml of 45% phenol in 1ml of 2%sodium nitropruside
and dilute to 100ml) (Prepare fresh every at
4hrsAmmonia:
 Dissolve 3.18gm of NH4Cl in 1lit.DDW.(Stable for two
month when preserve with CHCl3)

Procedure
 Bubble air through any gas sampling device to 10 ml
of absorbing reagent.
 The sampling rate should be 1-2 lit/min for adequate
sampling time.
 Transfer the sample in 25ml glass stoppred flask.
 Add 2ml of Buffer.
 Add 5ml of working phenol solution mix and then
add 2.5 ml of working hypochloride solution with
rapid mixing.
 Dilute to 25 ml and keep it in dark for 30 min.
 Measure developed blue colour at 630nm

Calibration
 Pipet 0.5,1,0,1.5 of working standard in
25ml flask and make 10 ml with
absorbing and then proceed as in
sample.
 These correspond to 5,10 and 15 µg
ammonia /25ml of sample.

Calculation
 µg/m3
NH3=W/V0
 Where:
W=µgNH3 in 25 ml from standard
V= Volume of Air sampled

Ozone (O3)
 UV Photometric
 Chemical Method
Standard: (µg/m3
)
8 hr. Average: 100 100
1 hr. Average 180 180

Ozone: Chemical Method
Principle
 Air containing Ozone is drown through a
midget impinger containing 10 ml of 1%
potassium iodide in a neutral (pH 6.8)buffer
composed of 0.1M disodium hydrogen
phosphate and 0.1M potassium dihydregen
phosphate.
 The iodine librated in the absorbing reagent
is determined spectrophotometrically at 352
nm.

Chemical Reaction
 O3+3KI+H2O=KI3+2KOH+O2
 The analysis must be completed within 30
min to 1hrs after sampling.
Range and sensitivity
 The range extend from 0.01ppm to about 10
ppm.
 The sensitivity of method is depend on the
volume of air sampled.

Precision and Accuracy
 The Precision of the method within the
recommended range is about
±5%deviation from the mean.
 The accuracy of this method has not been
established. Calibration is based on the
assumed stoichiometry of the reaction
with the absorbing solution.

Chemicals Required
 Potassium dihydrogen phosphate ( KH2PO4 ),
 Bisodium hydrogen phosphate ( Na2NH4 )
 Potassium iodide
 Sodium hydroxide

Reagents
 Dissolve 14 g of potassium dihydrogen
phosphate( KH2PO4 ), 14.20 g of disodium hydrogen
phosphate ( Na2NH4 ) and 10 g of potassium iodide
successively and dilute the mixture to 1 litre with distilled
water. Age at room temperature for at least 1 day before
use.
 Measure the pH and adjust to 6.8 with sodium hydroxide
or potassium dihydrogen phosphate solution. This
absorbing solution may be stored for several weeks in a
glass stoppered brown bottle in the refrigerator and for
shorter periods at room temperature without
deterioration.
 The absorbing solution should not be exposed to

Standard Iodine Solution
Dissolve 16 g of potassium iodide and 3.173
g of iodine successively and dilute the
mixture with distilled water to exactly 500 ml
to make a 0.05N solution. Age at room
temperature least one day before use.

Sampling
 Pipette exactly 10 ml of the absorbing solution
into the bubbler.
 Sample at a rate of 0.5 to 3 litres/min for up to 30
minutes.
 The flow rate and time of sampling should be
adjusted to obtain a sufficiently large
concentration of oxidant in the absorbing
solution.
 Approximately 2 µg of ozone may be obtained in
the absorbing solution at an atmospheric
concentration of 0.01 ppm by sampling for 30
minutes at 3 litres/min.

Calibration
 Prepare a 0.0025 N iodine solution by pipetting exactly 5
ml of the 0.05 N standard solution ( normality should be
checked before use ) into a 100 ml volumetric flask and
diluting to the mark with absorbing solution.
 Prepare four or more standard solutions in 25 ml
volumetric fasks by pipetting 0.1 to 1 ml portions of the
0.0025 N iodine solution into the flasks, diluting to the
mark with absorbing solution and mixing.
 Immediately after preparation of this series, read the
absorbance of each at 352 nm. The solutions should
cover the 0.1to 1 unit

Procedure
 If significant evaporation of solution occurs, add double
distilled water to bring the liquid volume to 10 ml. Read
the absorbance at 352 nm against double distilled water
within a 30 to 60-minute period after collection in a I-cm
cuvette or tube.
 Ozone liberates iodine through both a fast and a slow set
of reactions. Some of the organic oxidants also have
been shown to cause slow formation of iodine.
 Some indication of the presence of such oxidants and of
gradual fading due to reductants may be obtained by
taking several readings during an extended period of
time.
 Determine the blank correction (to be subtracted from
sample absorbance) every few days by reading the
absorbance of unexposed reagent.

Calculations
 Subtract the absorbance of the blank from the
absorbance of the standards. Plot corrected
absorbance's against the normality's of the standardized
solutions.
 From the line of the best fit the normality corresponding
to an absorbance of exactly one shall be determined.
 To obtain a value, M, representing microlitres of ozone
required by 10 m.l of absorbing solution to produce an
absorbance of one, multip!y this normality by the factor
1.224 X 103
.

Calculations continued……
 For I-cm cells, M should be approximately 9.6
Results for air samples may be computed from equation:
 Oxidant ( as O3), ppm = AM/V
where
 A = corrected absorbance, and
 v = volume of air sample in litres ) per 10 ml of absorbing solution
corrected to 25°C and 760 mmHg (correction is ordinarily small and
may be omitted).
NOTE - 1 mg/litre = 509 ppm of ozone at 25°C and 760 mmHg

UV Absorption
The UV photometer determines the concentration of Ozone
(O3) in a sample gas at ambient
pressure by detecting the absorption of UV radiation in a
glass absorption tube.
• Ozone shows strong absorption of UV light at 254nm
• Sample air is passed into the glass absorption tube
(measurement cell)
• Within the measurement cell a single beam of UV radiation
passes through the sample and is absorbed by the O3
• The Solar blind vacuum photodiode detects any UV that is
not absorbed
• The strength of the UV signal being detected is proportional
to the amount of UV light being absorbed by O3
• The analyzer uses the Beer-Lambert relationship to
calculate the ozone concentration

Sample
Inlet
Particulate
Filter
Absorption
(Measurement Cell)
Detector
Microprocessor
O3 Output
exhaust
UV source
O3 Analyzer Flow diagram
•O3 is not the only gas that absorbs UV (254nm), SO2 and
aromatic compounds also absorb radiation at this wavelength
•To eliminate these interferences a second cycle is performed
where sample air is passed through an ozone scrubber which
allows all interfering gases through but eliminates ozone thereby
accurately measuring interfering gases effects on signal and
removing them from the sample measurement signal

Benzene
 Gas Chromatography based continuous
analyzer
 Adsorption and desorption followed by GC
Standard:(µg/m3
)
Annual Average: 5 5

Principle of the Method
•A known volume of air is drawn through a charcoal
tube to trap the organic vapors present.
•The charcoal in the tube is transferred to a small,
graduated test tube and desorbed with carbon
disulphide.
•An aliquot of the desorbed sample is injected into a
gas chromatograph.
•The area of the resulting peak is determined and
compared with areas obtained from the injection of
standards.

Interferences
• When the amount of water in air is so great that
condensation actually occurs in the tube, organic
vapors will not be trapped. High humidity severely
decreases the breakthrough volume.
• When two or more solvents are known or suspected
to be presenting the air, such information (including
their suspected identities), should be transmitted
with the sample, since with differences in polarity,
one may displace another from charcoal.
• It must be emphasized that any compound which
has the same retention time as the specific
compound under study at the operating condition
described in this method is an interference.

Advantages of the Method
•The sampling device is:
–small,
–portable and
–involves no liquids.
•The tubes are analyzed by means of a quick,
instrumental method.
•The method can also be used for the
simultaneous analysis of
two or more solvents suspected to be present in
the same sample by simply changing gas
chromatographic conditions.

Disadvantages of the Method
One disadvantage of the method is that the
amount of sample, which can be taken, is limited
by the number of milligrams that the tube will hold
before overloading. When the sample value
obtained for the backup section of the charcoal
tube exceeds 25% of that found on the front
section, the possibility of sample loss exists.
During sample storage, the most volatile
compounds will migrate throughout the tube until
equilibrium is reached (33% of the sample on the
backup section).

Apparatus
Suction device
• For personal sampling : personal sampler
• For an area sample : any vacuum pump
Trapping device to retain the contaminants
Charcoal tubes
7cm long and 6 mmO.D.and 4mm I.D. ontaining 2 sections of
20/40 mesh activated charcoal separated by 2mm
portion of urethane foam.

Instrumentation
 Gas Chromatograph with a Flame
Ionization Detector
 Column (20ft X 1/8”) with 10% FFAP
stationary phase on 80/100meshes,
acid- washed DMCS chromosorb W
solid support
 A mechanical or electronic integrator
or a recorder and some method for
determining peak area.

 Micro centrifuge tubes, 2.5 ml, graduated.
 Hamilton syringes: 10µl and convenient
sizes for making standards.
 Pipettes: 0.5ml delivery pipettes or 1.0 ml
type graduated in 0.1ml increments.
 Volumetric flasks: 10ml or convenient
sizes for making standard solutions.

 Each personal pump must be calibrated
with a representative charcoal tube in a
line.
 This will minimize error associated with
uncertainties in the sample volume.
 In Rotameter, float reading should be in
proper place as directed in figure.
Calibration Of Sampling Pump

•Spectroquality Carbondisulfide
•Sample of Specific Compound Under
Study
•Grade A Helium gas
•Purified Hydrogen
•Filtered Compressed Air
Reagents

Procedure
•Glass ware: detergent washed and thoroughly
rinsed with distilled water
•Calibrate the personal pump
•Immediately before sampling break the tube to
provide an opening
•Place the charcoal tube in a vertical direction
•Air being sampled should not be pass through
any hose or tubing before entering the charcoal
tube

Analysis Of Sample
•The Charcoal in the first section is transferred to
the small stoppered tube.
•The separating section of foam is removed.
•The second section is transferred to another test tube.
•These two section are analyzed separately.
•Now in each tube add 0.5 ml of carbon disulfide.
•Carbon disulfide is toxic therefore all work should
be performed in hood.

•The de-sorption time should not exceed 3 hours.
•Condition the GC as per the type of instrument.
•Inject the aliquot of the sample in GC.
•The de-sorption time should not exceed 3 hours.
•Condition the GC as per the type of instrument.
•Inject the aliquot of the sample in GC.
Area Sample- Area blank
•De-sorption efficiency=
Area Standard

Convert the volume of air sampled to standard condition
of 250
and 760 Torr
The concentration of organic solvent in the
air sampled
Total mg x 1000
mg/m3
=
Volume of air
CALCULATION

Conversion ppm to mg
• Another method of expressing concentration is
ppm (corrected to standard conditions of 25o
C
and 760 mm Hg).
ppm = [(mg/m3
) x (24.45/MW) x (760/P) x
((T+273)/298]
where:
• P = pressure (mm Hg) of air sampled
• T = temperature (o
C) of air sampled
• 24.45 = molar volume (liter/mole) at 25'Cand
760 mm Hg
• MW = molecular weight
• 760 = standard pressure (mm Hg)
• 298 = standard temperature (o
K)

Benzo(a)pyrene
Solvent Extraction followed by HPLC/GC
Standard: ng/m3

Benzo(a)pyrene
 Polycyclic aromatic hydrocarbons (PAHs)
have received increased attention in recent
years in air pollution studies because some
of these compounds are highly carcinogenic
or mutagenic.
 In particular, benzo[a]pyrene (B[a]P) has
been identified as being highly carcinogenic.

This method is designed to collect particulate phase PAHs in
ambient air and fugitive emissions and to determine individual PAH
compounds.
It is based on high volume (- 1.2 m3/min) sampling method capable
of detecting sub ng/m3 concentration of PAH with a total sample
volume -480 m3/ of air over a period of 8 h with same filter.
It involves collection from air particulate on a fine particle (glass-
fibre) filter using high volume sampler for total suspended
particulatematter (TSPM) or respirable dust sampler for respirable
suspended particulate matter (RSPM or PM1O) and subsequent
analysis by Gas Chromatograph (GC) using Flame Ionization
Detector (FID).
If sampling period is extended to 24 h without changing the filter, it
may enhance sample loss due to volatility or reactions of PAHs on
collection media.
PRINCIPLE

INTERFERENCES
 The panicle phase PAH maybe lost from particle
fiIter during sampling due to resorption and
volatilization especially during summer months at
ambient temperature of 30°C and above.
 The method interference may be caused by
contaminations in low grade filter, solvent, and
reagent, if used.
 Glassware shall be properly cleaned (acid-washed)
followed by solvent rinsing prior to use.
 Matrix interferences may be caused by
contaminants, that is, hydrocarbons and other
organics that are co-extracted from sample. In this
organics that are co-extracted from sample.
 In this case clean-up by column chromatography
shall be required besides identification and
confirmation of individual analyte followed by mass-
spectrometer.

DETECTION LIMIT
The minimum detectable concentration in
term of BaP for a sampling period of 8 h (with
about 480 m3 of air passed) will be 2 ng per
cubic meter assuming 0.5 ml as the final
volume of sample extract after clean-up and
detectable concentration of 2 ng/pl of that
sample extract. High resolution mass-
spectrometry or high pressure liquid
chromatography can improve sensitivity down
to 1 ng/m3.

REAGENTS
 All solvents to be used should be of reagent
grade.
 Toluene, ultra-residue grade.
 Cyclohexane, ultra-residue grade.
 Tri-phenyl Benzene, ultra-residue grade.
 Solid PAHs Compounds, high purity to
prepare the standard PAH solution.
 Activated Silica Gel (60-100
meshes),chromatography grade.

APPARATUS
 Ultrasonicator, with compact tank/bath of 4.5 litre capacity and
producing -40 kHz frequency for extraction.
 Rotary Evaporator, buchi-type.
 Silica-Gel Column, 200 mm length, 5 mm
 internal diameter with teflon stopcock.
 GC-FID with Capillary Column
 Syringes, 1 @to 10 ~1.
 Flask and Beakers, 5-ml, lo-ml, 25-ml, 50-ml
 and 250-ml capacity.
 Variable Volume Micro-Pipettes, 0.5 ml and
 1.0 ml capacity.

PROCEDURE
 Collect sample through a high volume-
sampler (HVS) using glass fibre (EPM —
2000) filter paper perferably Whatmart or
equivalent) at a flow rate of -1.2 m3/min over
an extended period of time usually 8 h for
ambient air.

Sample Processing and Extraction
 Cut/punched at least 30 percent of total sample of
the exposed filter paper or measured fraction of it
into small strips/circtrlar pieces in a beaker/flask of
250-ml capacity.
 Add tri-phenyl benzene, an internal standard at this
stage for recovery test. Add about 100 ml of toluene
for extraction and keep beakers in ultrasonic bath
for 30 min (or for 6 using Soxhlet extraction
apparatus).
 Filter the extracts into evaporative flask of 250 ml
with the help of Whatrnan filter paper No. 20 or filter-
disc. Repeat the extraction twice and combine
extractants.

Sample Processing and Extraction
 Cut/punched at least 30 percent of total sample of the
exposed filter paper or measured fraction of it into small
strips/circtrlar pieces in a beaker/flask of 250-ml capacity.
 Add tri-phenyl benzene, an internal standard at this stage for
recovery test.
 Add about 100 ml of toluene for extraction and keep beakers
in ultrasonic bath for 30 min (or for 6 using Soxhlet
extraction apparatus).
 Filter the extracts into evaporative flask of 250 ml with the
help of Whatrnan filter paper No. 20 or filter-disc. Repeat the
extraction twice and combine extractants.

Sample Concentration
 Evaporate the toluene extracts using rotary evaporator with
water bath as cool as possible (temperature not exceeding
40”C).
 Do not evaporate up to total dryness.
 It should be stopped at near dryness (less than 1 ml,
visible). Add 2.0 ml of toluene to rinse the wall of
evaporation flask and transfer extract into a beaker of
5 ml capacity.
NOTE — Samples extraction should preferably be carried out within
a month of sampling.

 It is performed using silica gel column having length 200” mm, and inner
diameter (ID) 0.5 cm. Pour a slurry of 3 g deactivated silica gel (60-100
mesh size) in cyclohexane into the column.
 Eltrte toluene followed by cyclohexane through the column for
conditioning.
 Now introduce sample extract (concentrated, 2.0 or 3.0 ml) at the top of
silica column.
 Collect the PAH fraction with about 5 ml of cyclohexane. Collect all the
eluants into a rotary evaporator flask.
 Add another 30 ml of cyclohexane to the column to elute all organics of
interest. Collect all fractions into the flask and reduce to about 1 ml.
 Finally transfer into 5 ml capacity beaker/vials, dry and store in a dark
and cool place.
Clean-Up and Enrichment

Gas Chromatography Conditions
 Gas chromatography equipped with percent ionization detector
(FID), a split injector and capillary column (Phase cross linked 5 percent
phenyl,methyl-silicone) :25 m length, 0.2 mm inner diameter
 GC conditions:
 Injection — Port — Temperature : 320°C
 FID — Temperature : 320”C
 Oven — Temperature — Programme : Initial temperature
140°C, hold for 3 min
 Deg/min “c min
 Ramp A 6 250 6
 Ramp B 10 300 5
 Total run time :36 min

CALCULATION
 Calculate the concentration in (rig/@) of each
identified analyte in the sample extract (CJ as
follows:
cs = (AS Xcis)/(Al$X RF)
where
A, = area count of characteristic analyte
sample/peak being measured,
Ais = area count of characteristic internal
standardlpeak, and
C,, = concentration of internal standard.

Calculate the air volume from the periodic flow
reading taken during sampling using the following equation:
V = Average flow rate of sampling, m3/min x T
where
v = total sample volume at ambient conditions, in m3; and
T = elapsed sampling time, in min.
The volume of air sampled (VS) may optionally be converted to
standard conditions of temperature
and pressure (25°C and 101 kpa) using the following equation:
V,= VX (P. / 101)X [298/(273+ T.)]
where
v= total sample volume under ambient
Pa =conditions, in m3;
T, = ambient pressure, in kPa; and
ambient temperature, in “C.

Solvent Extraction followed by
HPLC/GC
Soxhlet Appratus GC, Capillary Column
Water In
Water Out
Condenser
Flask
s
Sample
Solvent

Metals
Pb
 EDXRF Using Teflon filter
Standard:(µg/m3
)
Annual Average: 0.5 0.5
24 hr. Average 1.0 1.0
Arsenic & Nickel
AAS/ICP method after sampling on EPM 2000 or equivalent
Standard:(ng/m3
)
Industrial, Residential, Ecologically
Sensitive Rural& other Areas
Areas
Annual Average: (As) 6.0 6.0
Annual Average: (Ni) 20.0 20.0

Sample Collection and Analysis
 Metals are associated mainly with the particulate
matter therefore collected on EPM-2000 cellulose
membrane filter paper by any dust collecting device.
 Calculate the dust collecting area of filter.
 This filter will be digested with digestion mixture (6:1
of nitric acid and perchloric acid) and digested at
1000
C.
 Digested samples will be filtered through Whatman
filter paper (Grade No1)
 Make the volume up to 25 ml with double distilled
water and analyzed for Pb, Hg, Cu, Cd, Zn and Ni
using AAS.

Calculation
Metal Concentration (µg/m3
)
= (Concentration in sample- Blank) x Area of filter
Volume of air sampled

Carbon Monoxide
Non dispersive infrared spectroscopy (NDIR)
Standard: mg/m3
8 hr.Average 02 02
1 hr.Average 04 04

Carbon Monoxide
Non dispersive Infrared Gas filter Correlation
The measurement of Carbon Monoxide is completed via the following
principles and measurement techniques:
Measurement cell theory
•CO absorbs infrared radiation (IR) at a wavelength near 4.7 microns
•IR radiation (at 4.7 microns) is passed through a 5 meter path length
through sample air
•The strength of the signal received is proportional to the amount of CO
in the sample as shown in the Beer Lambert Law
•A band pass filter is fitted to the signal detector to ensure only light near
4.7 microns wavelength is detected

Sample
Inlet
Particulate
Filter
Absorption
(Measurement Cell)
IR Detector
Microprocessor
CO Output
exhaust
IR source
Gas Filter
Wheel
CO Analyzer Flow diagram
•A gas filter correlation wheel is combined with this system in the light
path.
•This wheel contains 3 parts to increase measurement accuracy, CO,
N2 and the mask
•The CO window contains a saturation of CO which acts as a reference
beam
•The N2 window does not absorb IR at 4.7 microns and is used during
normal CO measurement
•The mask totally blocks the light source and is used to determine
background signals and the strength of other signals relative to each
other and the background

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