TBS/CDC 2 (5794) P 3 
© TBS 2018                                                                                                                              First Edition 201 8  
  
  
DRAFT TANZANIA STANDARD  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
TBS/CDC 2 (5794) P 3 - Linear alkylbenzene - Specification  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
TANZANIA BUREAU OF STANDARDS  
  
 
 TBS/CDC 2 (5794) P 3  
 
©TBS 201 8 All right reserved                                                                      First edition 201 8 
 Foreword  
 
This Draft Tanzania Standard is being  developed by the Soap and Detergents Technical Committee under 
supervision of the Chemicals Divisional Standards Committee and it is in accordance with the procedures 
of the Bureau.  
In the preparation of this Draft Tan zania Standard assistance was drawn from IS 12795: 1989 (Reaffirmed 
2016) Linear alkyl benzene - specification ; Prepared by the Indian Standards Institutes  
In reporting the results of analysis of a test if the final value is to be rounded off, it shall be done in 
accordance with TZS 4  Rounding off numerical values  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 TBS/CDC 2 (5794) P 3 
 
©TBS 2018 All right reserved                                                                                            First edition 2018  
 
  
DRAFT  TANZANIA  STANDARD                                                                          TBS/CDC  2 (5794)  P3        
Linear alkylbenzene - Specification  
1 Scope  
This Draft Tanzania Standard prescribes the requirements and the methods of sampling and test for linear 
alkylbenzene . The standard is intended for Linear alkylbenzene suitable for detergent s preparation.  
2 Normative references  
The following referenced documents are indispensable for the application of this document ; the latest 
edition of the referenced document (including any amendments) applies.  
TZS 35, Soaps – Sampling and test methods  
 
TZS 1396 -2/ISO 672 Soaps — Determination of m oisture and volatile matter content — Oven method  
 
TZS 59/ ISO 3696 Water for analytical laboratory use – Specification and test method  
ISO 3839  Petroleum products -- Determination of bromine number of distillates and aliphatic olefins -- 
Electrometric method  
ISO 1523 Determination of flash point -- Closed cup equilibrium method  
ASTM D1298 Standard Test Method for Density, Relative Density, or API Gravity of Crude Petroleum and 
Liquid Petroleum Products by Hydrometer Method  
ASTM D4952  Standard Test Metho d for Qualitative Analysis for Active Sulfur Species in Fuels and 
Solvents (Doctor Test)  
ASTM D7344  Standard Test Method for Distillation of Petroleum Products and Liquid Fuels at 
Atmospheric Pressure (Mini Method)  
ASTM D156  Standard Test Method for Saybolt Colour of Petroleum Products (Saybolt Chromometer 
Method)  
3 Requirements  
3.1  General requirements  
Linear  alkylbenzene shall be a clear colourless liquid with a desirable  odour.  
3.2 Specific requirements  
The material  shall also comply with require ments specified in T able 1 .  
 
 
 
                                                                                                   TBS/CDC 2 (5794) P 3  
 
©TBS 2018 All right reserved                                                                                            First edition 2018  
 
 
3 
 Table  1 – Requirements for Linear  alkylbenzene  
 
S/N Characteristic  Requirement  Method of test  
i.  Colour , 
Saybolt, Min  
30  
ASTM D156  
ii.  Specific gravity at 15 °C/15°C  0.858 – 0.868  ASTM D1298  
iii.  Moisture, mg/kg , Max 100 TZS 1396 -2/ISO 672  
iv.  Doctor test  
Negative  ASTM D4952  
v.  Flash point (closed cup) °C, Min 130 ISO 1523  
vi.  Bromine number ., Max 0.05 ISO 3839  
vii.  Ready biodegradability of sulphonate*  92 Annex A 
viii.  Distillation, 95 percent recovery at °C, Max 320 ASTM D7344  
ix.  Molecular weight  236 - 246 Annex B 
x.  Paraffins, percent by  mass, Max 0.2 Annex C 
xi.  Sulphonability, percent  by mass, Min 98 Annex D 
xii.  Chain -length distribution,  
percent  
a) Less than C 10, Max 
b) C10, Max 
c) C10 + C 11 
d) C12 
e) C13, Max 
f) C14, Max  
 
0.5 
15.0 
30.0 – 55.0 
25.0 – 50.0 
30.0 
5.0 Annex E 
*Linear alkyl benzene is to be sulphonated before carrying out ready biodegradability test, as given in 
Annex D 
 
 
4 Pack aging and labelling   
4.1 Pack aging  
The material shall be packed in moist -free container  as agreed to between the purchaser and the 
supplier.  
4.2 Labelling  
The container shall be securely closed and labelled  with the following particulars:  
a) Name of the material;  
b) Name and address of the manufacturer ;  
c) Recognized  trade mark (if any ) 
d) Country of origin ; 
e) Net volume of the product ;  TBS/CDC 2 (5794) P 3 
 
©TBS 2018 All right reserved                                                                                            First edition 2018  
 
 f) Batch number or lot number; and  
g) Month and year of manufacture  (refer on MSD)  
5 Sampling  
The method of drawing representative samples of the material, number of tests to be performed and the 
criteria for conformity o f the material to the requirements of this specification shall be as prescribed in  
TZS 35. 
 
6 Quality of Reagents  
Unless specified otherwise analytical  chemicals and distilled water (see TZS 59 ) shall be used in tests.  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
                                                                                                   TBS/CDC 2 (5794) P 3  
 
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5 
  
Annex A  
(Normative)  
Determination of biodegradability of sulphonates  
( shake culture method)  
 
A.1 Outline of the method  
In this test, micro -organisms are inoculated into a flask that contains a chemically defined  microbial growth 
medium (basal  medium) and the  surfactant to be tested. Aeration is accomplished  by continuous shaking 
of the flask. Following two adoptive transfers, biodegradation is determined by measuring the reduction 
in surfactant content during the test period.  
A.2 Apparatus  
Shaking Machine  
A reciprocating shaker operating at about 128 strokes of 51 to 101.6 mm/mm or a gyratory shaker  
operating at 225 to 250 rev/min with an amplitude of 25 to 51 mm should be used. Other shakers may be 
used if equivalent aeration can be demonstrated.  
A.3 Reage nts  
A.3.1  Purity of Water  
Either distilled or deionized water may be used ; must be free of bacteriostatic materials. Water derived  
from steam condensate in many c ases may contain amines which are inhibitory to microbial growth.  
A.3.2  Basal Medium  
A.3.2.1  The composition of the basal medium shall be as described in Table 2 below :  
Table 2: C omposition of the basal medium  
Material  Quantity (g)  
Ammonium chloride (NH 4Cl)  3.0  
Potassium hydrogen phosphate (K 2HPO4) 1.0  
Magnesium sulphate heptahydrate(MgS O4.7H 2O) 0.25 
Potassium chloride (KCl)       0 25  
Ferrous sulphate (FeS O4.7H 2O)    0.002  
Yeast extract         0.30  
Water  (see A.3.1)           1.01  
 TBS/CDC 2 (5794) P 3 
 
©TBS 2018 All right reserved                                                                                            First edition 2018  
 
 A.3.2. 2 The basal medium may be prepared by sequentially  dissolving the dry ingredi ents in water, or by 
adding stock solutions of the salts. The yeast extract shall be added in dry form immediately before use, 
or alternatively, solutions containing yeast shall be sterilized and maintained  sterile if held for more than 
8 hours before beginning the test. The basal medium shall be dispensed into one of the following  flasks: 
500 m L in a 1 L flask, 1 000 m L in a 2 L flask and 1 500 m L in a 4  L flask. 1 L and 2  L flasks are best 
suited for a gyratory  shake and the 4  L flask f or a reciprocating  shaker.  
A.3.3 Microbial Culture  
A.3.3.1 Source  
The microbial inoculum may be obtained from any of the following sources.  
A.3.3.1.1  Natural sources (soil, water, sewage, activated sludge, etc).  
A.3.3.1.2  Laboratory cultures (activated sludge, river die-away, etc).  
A.3.3.2 Maintenance of Culture  
If desired, the culture may be maintained as a shake flask culture by weekly transfers in the basal 
medium. For each weekly transfer use m L of 7-day culture for e ach 100 m L of fresh medium .  
A.4 Procedure  
Add 30 mg/ L surfactant to the flasks containing basal medium. If surfactant stock solutions are 
used,stability during storage shall be confirmed, use one flask for each surfactant being tested and one 
blank flask  containing all basal medium components but with no surfactant. Using the culture described 
in A.3.3  inoculate the flasks. Use the same culture for all flasks including blank. Use  1 mL of inoculum for 
each 100 m L of basal medium in the flask. Place the flasks containing basal medium, surfactant and 
inoculum on a shaking machine that will produce acceptable aeration and mixing for biodegradation. 
Maintain the temperature of the flask contents at 25 °C ± 3°C.  
Prior to beginning the biodegradation test, make two 72  h acclimation transfers from the flasks. To follow 
the course of biodegradation, removesamples from the shake flasks for analysis. Samples shall be taken 
during the 8-day test at zero time (immediately afte r inoculation and mixing of the flask contents) and on 
the seventh and eighth days. Samples at zero time of the two adaptive transfers are desirable to ensure 
proper initial concentration. Unless analyses are run immediately, the addition of 1 m L of 
formal dehyde /100 mL of sample shall beused for preservation of any sample (0 time or 7 or 8 days). 
When preservative is used, add to all  samples including blank. Since the analytical result from the blank 
sample is used to correct the results from other flasks, use the same sample size (or dilution factor) for 
the blank as used for the other  samples  
A.5 Calculation  
Calculate net surfactant concentration by subtracting the analyzed blank values from the analyzed  
values for the other flasks. Calculate the percent age removal from the reduction in surfactant  
concentration as follows:  
Percentage removal (day x)  
= [(𝑆0−𝐵0)−(𝑆𝑟−𝐵𝑧)
(𝑆0−𝐵0)]×100  
Where; 
𝑆0 and 𝑆𝑟= analysis of test surfactant cultures, and  
𝐵0and 𝐵𝑧= analysis of blank cultures, on days 0 and x, respectively.                                                                                                    TBS/CDC 2 (5794) P 3  
 
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 The result shall be calculated as the average of the seventh and eighth day percentage removals.  
 
 
Annex B  
(Normative)  
Determination of molecular weight  
(Gas liquid chromatographic method)  
B.1 Outline of the method  
The gas liquid chromatogram of the sample is recorded as described in C.1 and assignments made as in 
B.2. 
B.2 Apparatus  
Gas liquid chromatography  
B.3 Procedure  
B.3.1  The linear alkylbenzene (LAB) sample is injected and the chromatogram is obtained as per the 
method described in C.3. Calculate the weight percent of all the linear alkylbenzene isomers; for  example,  
C10, C11, CI2 ... etc; after adjusting its area percent  with response factors obtained by inject ing the synthetic 
blend under identical conditions. Add up all the C 10 isomers which will be the total C 10-LAB mass percent 
in the sample. Likewise calculate for all the carbon number LAB's such as C 11-LAB, C 12-LAB,  etc. 
Calculate the total linear alkyl benzene content in the sample by adding up all weight  percentages of C 10-
LAB, C 11-LAB, etc.  
B.4 Calculation  
B.4.1  The percentage of different homolog LAB with respect to total linear alkyl benzene in the sample 
is calculated as follows:  
X = 𝑌
𝑍 X 100  
where  
x = weight percent of LAB -C10, LAB -C11….etc, with respect to LAB in the sample;  
Y = weight percent of LAB -C10, LAB -C11….etc, in the sample; and  
Z = total linear alkyl benzene in the sample.  
B.4.2Average molecular weight  
The average molecular weight of linear alkylbenzene is obtained by multiplying eachpercentage 
homolog LAB, as obtained from B.4.1 , With its molecular weight and adding up all thevalues.  
𝑀=(𝐴×𝐶10+𝐵×𝐶11+𝐶×𝐶12+𝐷×𝐶13+𝐸×𝐶14+⋯)
100 
where  TBS/CDC 2 (5794) P 3 
 
©TBS 2018 All right reserved                                                                                            First edition 2018  
 
 M = average molecular weight of linear alkyl benzene;  
C10, C11 ... etc = weight percent of LAB -C10, LAB -C11, etc; and  
A, B,  C. ... etc = molecular weight of LAB -C10, LAB -C11, etc 
 
Annex C 
(Normative)  
Determination of Paraffins  
 
C.1 O utline of the method  
The sample to be analyzed is injected into a gas chromatograph that is equipped with fused silica  capillary 
column. A quantitative blend, containing known amount of normal paraffins in linear alkyl benzene (LAB) 
is chromatographed und er identical conditions. The calibration chromatogram thus developed is used to 
ascertain the normal paraffins in the sample by comparing the retention of the normal paraffins to the 
observed retention times  of the components obtained in the synthetic mixt ure. Quantitative results are  
obtained from the measured areas of the recorded peaks, adjusted for differences in response by the use 
of factors determined from the analysis of synthetic blend.  
 
C.2 Apparatus  
Gas liquid chromatography  
C.3 Procedure  
C.3.1 Inject C 10 to C 14 individual normal  paraffins namely decane, undecane dodecane, tridecane and  
tetradecane into GC and find out the retention times of each paraffin. Prepare a synthetic blend 
containingclose to 0.2 by mass of total normal paraffin in linear  alkyl benzene. Now inject the synthetic 
blend and run the chromatogram. Identify the normal paraff in peaks from C 10 to C 14. Calculate the area 
per-  
cent of individual normal paraffin and sum it up to get total area percent of the total normal paraffin in  the 
blend. Calculate the area response factor as given in C.4.1.  
 
C.3.2 Inject linear alkylbenzene sample and run the chromatogram. From the area percent of  
total normal paraffin calculates the weight percent as given in C.4.2.  
 
C.4 Calculation  
C.4.1 The area response factor is calculated as  
follows:  
 
𝐹=𝑊
𝐴 
 
Where; 
F = response factor;  
W = weight percent of total normal paraffin in the blend; and  
A = area percent of total normal paraffin in the blend;  
 
C.4.2 The weight percent of tot at normal paraffin in linear alkyl benzene as follows:  
Percent total normal paraffin in linear alkyl benzene = B x F  
                                                                                                   TBS/CDC 2 (5794) P 3  
 
©TBS 2018 All right reserved                                                                                            First edition 2018  
 
 
9 
 where  
B = area percent of total normal paraffin obtained from the chromatogram; and  
F = response factor of total normal paraffin.  
 
 
 
 
Annex D 
(Normative)  
Determination of Sulphonability  
 
D.1 Outline of the method  
A known mass of  linear alkyl benzene of known molecular mass is sulphonated with 20 % oleum. Knowing 
the mass of the product after sulphonation and its active matter content, the percent sulphonability is 
calculated.  
D.2 Apparatus  
A 500 -ml capacity 4 -necked round  bottom flask, with standard joints, is fitted with a mercury -sealed stirrer,  
thermometer ( 0 °C– 110 °C) and a 100ml, capacity addition funnel with pressure equalizing  side-arm (see 
Fig. 1). A guard -tube filled with granular, fused calcium chloride is inserted into the fourth neck of the flask.  
 
 
….Standard socket joint, B 24  (check correctness of drawings)  
 
Fig. 1 Apparatus for determination of Sulphonability  
TBS/CDC 2 (5794) P 3 
 
©TBS 2018 All right reserved                                                                                            First edition 2018  
 
  
D.3 Reagents  
D.3.1 20% Oleum  
D.3.2 Purified Hyamine 1622  
Commercially -available, Hyamine 1622 is crystallized  6 to 7 times from chloroform -petroleum ether (60 °C-
80°). I n the last crystallization , it is dissolved in chloroform and filtered through filter paper to removetraces  
of dust and dirt. Then, the chloroform solution is concentrated on a hot -water bath and petroleum ether is 
added to the hot solution until it is slightly hazy. This solution is then cooled, scratching the sides with a 
clean glass rod. The separated crysta ls are filtered in a Buchner funnel under vacuum  
and the cake of crystals pressed dry with an inverted bottle stopper. The crystals are then scraped gently 
from the filter -paper into a glass dish and dried subsequently on a steam -bath. The melting point o f the 
dried crystals is 163.5°C.  
D.4 Procedure  
D.4.1 The empty 500-ml round bottomed flask,fitted with stirrer and thermometer (partly  
coming in contact with the reaction mixture) is weighed, to the second decimal 100.00 g of the linear alkyl 
benzene sam ple is now weighed into it. The mercury seal and calcium chlo ride guard tube are fitted. 120g 
of 20 % oleum is weighed into the addition funnel, which is stoppered at once and fitted to the 4 -necked 
flask. The linear alkyl benzene is then cooled with stirri ng in a bath containing ice and water  
to 20°C. Dropwise addition of the 20 % oleum is started. The reaction is exothermic, but, by adding more 
ice to the bath, reaction temperature is held below 20°C  and a fairly fast rate of addition of oleum is 
maintaine d. After all the oleum is added, reaction mixture temperature  is allowed to come up to 40°C, by  
replacing ice and water in the bath with warm water. The reaction mature is maintained at 40°C with 
stirring for 1 h. The calcium chloride guard tube, additiona l funnel and mercury seal are removed. The 
outside of the flask is wiped dry and weighed, as before, with stirrer and thermometer, to the second 
decimal  place . The net weight of the contents after sulphonation is thus found out . Its anionic active  
matter content is then found out as given in D.4.2 below . 
D.4.2 Determination of Anionic Active Matter  
D.4.2.1 Sample solution preparation  
Weigh a suitable quantity of the sample containing100  mg to 160 mg of anionic active matter  per 100 m L 
of solution. Fo r this take an appropriate  quantity of sample and neutralize with  required quantity of sodium 
hydroxide solution  to get sodium alkyl benzene sulphonate. About1 g of sodium alkyl benzene sulphonate 
per500 m L of the solution is suitable.  
D.4.2.2  Procedure  
Pipette 10 mL sample  solution  into a 100  mL graduated cylinder provided with a glass stopper . Add 15 
mL of chloroform and 25 m L of methylene blue reagent to the cylinder  then Shake well. The chloroform 
layer (lower )shall be coloured blue or greenish blue.A dd from the burette hyamine 1622 solution (see 
D.3.2) slowly, initially in portions of0.2 m L. After each addition, stopper the cylinder,shake well and allow 
the phases to separate.  Initially the chloroform phase will be colouredblue or greenish blue. Toward s the 
end the  colour would start migrating to the aqueouslayer. Note the reading at which the colour  intensity 
in both the phases is the same when  viewed under standard conditions of light, fo r example, against a 
white porcelain tile unde r normal daylight.  
Calculate the molarity of hyamine 1622 solution  (i.e. benzethonium  chloride solution ) as follows:  
Molarity of benzethonium  chloride solution, T2 =10 𝑇1
𝑉1                                                                                                   TBS/CDC 2 (5794) P 3  
 
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11 
 where  
T1 = molarity of sodium lauryl sulphate  solution, and  
V1 = Volume in ml of benzethonium  chloride  solution added.  
 
D.5 Calculation  
Percent sulphonability = 𝑀1× 𝐴 × 𝑀2
100 (𝑀2+80) 
Where  
𝑀1 = netmass of reaction mixture after sulphonation;  
A = percent active matter of the sulphonated mixture; and  
𝑀2 = average molecular mass of the sample.  
 
 
 
Annex E  
(Normative)  
Determination of chain length distribution  
The gas liquid chromatogram of the sample is taken and recorded as described  in C.3 and assignments 
made as in B.3. Thereafter, the chain length distribution of the sample is calculated as given in B.4.1 .