Analysis of
Adulteration
Dr. Suchita Rawat
Mphil, NET,PhD
Unit 1: Introduction to Forensic Chemistry (co faculty) 10 hours
Arson: Definition and introduction; Chemistry of fire; Cause and origin of fire; Fire scene patterns; Recognition of type of fire; Role of a
forensic investigator; Examination of crime scene; Collection, preservation and analysis of clue materials in: arson, accidentaland
vehicular fire; Analytical techniques in arson investigation: Pyrolysis Gas chromatography, Headspace Gas chromatography; Post-flashover
burning.
Definition,history,scopeandbranchesoftoxicology;Roleofaforensictoxicologist;Poison:definition,dosage,classificationbasedon
origin,modeofaction,chemicalnature;Modeofadministration;Factorsaffectingtheactionofpoisons;Antidotes:Definitionandtypes;
Typesofexhibitsencountered;Collectionandpreservationofdifferentspecimensinfatalandsurvivalcases:choiceofpreservations,
containers,labelling,sealingandstorage.
Analysis of adulteration in: cement, oils, fats, cosmetics, paints, gold, silver, tobacco, tea, sugars and salts; Analysis ofadulterants
like pesticides, metals and their alloys in water, cold drinks, milk and food materials
Unit 5: Introduction to Toxicology 14 hours
Unit 3: Arson Analysis 12 hours
Cement bag
(note/random sampling /1kg in
airtight container or
polythene bag , cover with
brown paper )
Sampling of Small
Quantities
(Less than 12 bags or
packages)
(1kg from each bag)
Sampling of large
Quantities
(More than 12 bags or
packages)
(grouping of bags/ 20% form
each)
Sampling
METHODS OF ANALYSIS
Test Procedure Observation
Thymolphthalein Test
(Thymolphthalein Indicator 0.1%
in ethyl alcohol)
100-150 mg of cement sample +
1-2 ml water + 2 drops of
indicator
blue colour indicates the
presence of cement
No colour indicates that the
sample is stone powder (poly
silicates of calcium, magnesium
and iron)
Heat test
Take 0.5 gm of sample, heat it for about 20 min. on a
steel plate.
a). Change in colouradulterated cement.
b). No change in colourunadulterated cement.
Performance Test:
Make thick slurry of cement with about 1 part of cement with one part of water and put
in an empty matchbox. The cement gets hardened. The performance is tested after 24 hrs.
just by removing matchbox and checking approx. strength of the cement by fingers, if the
block breaks easily, the setting property is said to be poor. If the block does not break by
fingers. The performance is said to be good.
Acid insoluble:
0.5 -1.0 gm cement + 20 ml water to
make a paste+ 5 ml conc. hydrochloric
acid + 20 ml water, stir, digest on
water bath for five minutes, no lumps
should be formed.
Digest further for another 10 minutes,
filter through ashless filter paper till
chloride free.
Residue dried in oven and further
incinerated in furnace at 800°C-900°C
for 1 hr.
weigh the residue, till constant weight.
Calculate percent acid insoluble
Silica
Concentrate filtrate from previous acid
insoluble test (insoluble acid) on hot plate to
dryness (without charring)
then add 20 ml 1:1 Hydrochloric acid and
digest on water bath for 10 minutes stir well,
and filter on ashless filter paper till chloride
free
Dry the residue (Precipitated silica) in oven
for 1hr
incinerate in furnace at 800°C-900°C for 1hr
weigh the residue, till constant weight. Weight
of silica obtained is noted.
*(20% Silica = 100% cement).
Combined Ferric Oxide and
AluminaConcentrate the filtrate to about 200-ml by boiling
then add 2-3 drops of nitric acid to oxidiseany
ferrous iron to ferric condition.
Add 1-2 grams of ammonium chloride, stir, and then treat the
filtrate with conc. ammonia solution till smell of ammonia persists
then boil the solution containing the ppts. of Fe and Al hydroxides
for few minute
filter and wash the ppt. with hot water
Dry the ppt. in oven and ignite in platinum crucible till
constant weight at 1050°C to 1100°C.
Weigh as alumina and ferric oxide.
Determination of Calcium by EDTA Titration
Take filtrate from ferric oxide and alumina
determination in 250 ml Vol. flask adjust Vol. to 250
ml.
Take out 25ml soln. in titration flask add 50 ml
water, 5ml (1:1) glycerol with constant stirring then
add 5ml diethylamine, further add 5-6 pellets of
NaOH (pH should be more than 12) shake well
further add 50mg of Patton Reeder`s indicator
(Grind 10mg of the indicator with 10gm of sodium
sulphate.) and shake well
titrate against 0.01M EDTA soln. colour change
violet to blue.
1ml 0.01 M EDTA= 0.5608 mg of CaO. (60 % CaO =
100% Cement) andCaO% = 3 Silica %
Direct Cement % by acid titration
Take 0.5 gm cement in a conical flask add
50ml of 0.5 N HCl, digest on water bath for
30 minutes, add 50 ml water
titrate against 0.5 N NaOH using
phenolphthalein as an indicator
Colour change is colourlessto pink.
Cement %= 28* N(N= Normality of NaOH).
Mortar,is the mixture of sand and cement for
plastering the brickwork
SAMPLING
1-2 Kg of mortar sample accompanied by 1 kg each of
cement and / or lime and sand if available from the
field shall be sent for analysis.
Every article should be independently packed.
Testing of Mortar
Heat good piece of mortar approx. 200 gmsis heated in oven at 110°C for
15 min. cool and then weigh. Separate the cement portion from sand by
slowly grinding the lump in iron mortar.
sieve the material and make three fractions. Powder, fine sand and
coarse sand.Weigh individually and record.
take about 5-10 gm of each fraction in beaker, add 5-10 ml 3.3 N HCl
till all the material is wet with HCl, if required, add further 5-10 ml
HCl, to dissolve the material
The cement portion gets dissolved and sand portion gets separated
from cement, digest on water bath for 10 minutes & filter the liquid
through filter paper, wash with water till chloride free.
The filtrate is evaporated and silica determined as in earlier part, from silica
cement portion in each fraction is determined, from total weight, weight of sand
obtained by subtracting wt. Of cement and hence the ratio of cement to sand is
calculated. Also % of cement in the sample is calculated.
EDTA Titrations:For filtrate same as cement titration with EDTA normally the
ratio of cement: sand used in plastering work is 1:4 (The ratio used for compound
walls and such other work is 1:6 to 1:8).
Concret,is the hard mass obtained by solidification of
the inert material like sand, coarse stone, water and
cement.
Sampling:
Concrete lumps, about 3-5kg accompanied by 1 kg each
of cement, sand and aggregate if available from the
field shall be sent for analysis.
Every article should be independently packed.
Testing of Mortar
About 1/2kg sample is required for analysis dry the piece from
slab/beam in oven at 110°C for 15 minutes., cool, and weigh.
Then grind the sample so that cement particle gets separated from
sand and aggregate.
Sieve the bulk with different mesh size sieves, to separate powder,
fine sand, coarse sand and aggregate. Weigh the fractions so
separated individually.
Take about 5-6gm from powder fraction and fine sand fraction, about
50-60 gm from coarse sand and about 100-150 gmsof aggregate
fraction for actual silica and calcium oxide determination.
Take all the four fractions as above in 250 ml beakers, add sufficient quantity of
3.3 N HCl to dissolve the adhering cement particles. Then digest on water bath
for 10-15 minutes and filter. The filtrate so obtained is used for silica
determination.
SILICA
Evaporate the filtrate to dryness on hot plate, dry silica remains in the
beaker along with calcium and aluminiumsalts.
Then add 3.3 N HCl and digest on water bath for 5 mins. Filter the
silica through ashless filter paper, wash with water until chloride free.
Dry the silica in oven and further in furnace at 800°C-1000°C for 2
hrs, Wash the silica so obtained. From silica calculate the weight of
cement obtained in different fractions(20% silica = 100% cement).
Take sand and fine sand fractionstogether. Thus calculate the total
cement, total sand and total aggregates present in the sample, and
hence calculate the ratio of cement: sand: aggregate also calculate the
cement percentage.
From filtrate of silica, calculate CaO% as detailed in cement, from CaO% also
calculate the % cement in each fraction, and hence get the ratio of cement: sand:
aggregate, and also % of cement in the sample. Compare the results obtained by
silica and CaO.
cosmetics refer to substances or mixtures that are
externally rubbed, poured, sprinkled or sprayed on,
introduced into or otherwise applied to the body or
ingested orally to clean, protect, enhance, beautify,
promote attractiveness or modify the skin’s
appearance.
skincare hair care
colour (make-up) fragrances
toiletries/others
A systematic review of heavy metals contamination in
cosmetics
Instrumental methods
Sample preparation
•to convert the sample to a liquid form : a
mixture of concentrated acids, such as
nitric acid and hydrogen fluoride or
sulphuricacid and nitric acid,.
•For complete oxidative digestion: chloric
acid or hydrogen peroxide is added.
A systematic literature review on the current detection tools for
authentication analysis of cosmetic ingredients
Cosmetic products are often formulated using water and oil based
ingredients.
The oil-based ingredients are naturally or synthetically derived from animal
fats and vegetable oils.
The animal fats and vegetable oils composed of esters of the alcohol such as
glycerol (propane-1,2,3-triol; CH2OHCHOHCH2OH) and long-chain carboxylic
acids (often known as fatty acids; RCO2H), where the alkyl groups contain
between 7 and 21 carbon atoms.
Fatty acids can be divided into two main categories, namely, saturated and
unsaturated fatty acids. The most common fatty acids in fat/oil are
composed of palmitic (C16:0) and stearic acids (C18:0), besides
monosaturated oleic (C18:1) and polyunsaturated linoleic acids (C18:2).
Health Effects of Dyes,
Minerals, and Vitamins Used in
Cosmetics
oils, fats, tea, sugars and salts
TOCP contaminates the tricresylphosphates—slightly
yellowish, viscous, oily chemicalscommonly used
industrially in plasticizers, hydraulic fluids, lubricants,
glues and adhesives, solvents, and flame retardants.
In the winterization process,the oil is cooled from room
temperature to a predetermined temperature of crystal-
lization. The cooled oil is kept at this temperature for a
certain period of time prior to the separation of solid phase
from the liquid oil by filtration of the oil-solid fat slurry.
Edible Oils & Fats
Detection of Rancidity in Edible Oil and Ghee
Rancidification is the process of complete or
incomplete autoxidation or hydrolysis of fats and
oils when exposed to air, light, moisture, or bacterial
action, producing short-chain aldehydes, ketones
and free fatty acids. When these processes occur in
food, undesirable odors and flavors can results
Oil + HCL+ 0.1% phloroglucinol solution in ether
after 30 minutes red or pink coloration in acid layer
Edible Oils & Fats
Detection of Argemone Oil
Oil + 1) 0.5 ml of 2% Salicylic acid
solution, 2) 2 ml of Conc. HNO3 and 3)
Finally 2-4 drops of Conc. H2SO4 : A
crimson red color within 20-30 sec
indicates the presence of argemone oil
Edible Oils & Fats
Detection of Mineral Oil
oil sample + Alcoholic Potash (KOH in aldehyde
free alcohol) . Heat in boiling water bath for 15
minutes Any turbidity shows the presence of
Mineral oil greater than 1%.
Edible Oils & Fats
Detection of Castor Oil in Edible Oil
oil + petroleum ether (Shake vigorously for 2 minutes) +
ammonium molybdate reagent Instantaneous development
of turbidityindicates presence of castor oil
Edible Oils & Fats
Detection of KaranjiaOil in Edible Oil
Oil + antimony trichloride solution in chloroform
Appearance of a canary yellow or orange color
indicates presence of Karanja oil
Edible Oils & Fats
Detection of Mobile (Lube) Oil in
Edible Oil
Oil + Alcoholic potash, . Heat till de-
colourise+ dichloroquinolchloride and
Warm the tube. The appearance of the
blue color indicates the presence of a
compound of triorthocrysylphosphate.
Gold,silverandcopper,normallystandardmix
Of
goldpurityarrivesas91.6%ofgoldand8.4
%ofeithercopperorsilveror
combinationofboth.
• Ir, Ru and Osbelong to the platinum group
of metals. When mixed with gold they do
not alloy but are dispersed in the gold
Ir, Ru and Osaddition ranging from 0.1%
to 0.5% with following combination:
Iridium; Iridium and Ruthenium; Iridium
and Osmium
GOLD ADULTERATION
aqua regia,mixture of concentrated nitric and hydrochloric acids (1:3)
Column 1 -30 m ×0.25 or 0.32 mm ID fused silica capillary column chemically bonded with
SE-54 (DB-5 or equivalent), 1µ film thickness.
Column 2 -30 m ×0.25 mm ID fused silica capillary column chemically bonded with 35 %
phenyl methylpolysiloxane(DB-608, SPB-608, or equivalent), 25 µm coating thickness.