DOI: 10.1007/s10967-008-7332-2 Journal of Radioanalytical and Nuclear Chemistry, Vol. 279, No.3 (2009) 725–731
0236–5731/USD 20.00 Akadémiai Kiadó, Budapest
© 2008 Akadémiai Kiadó, Budapest Springer, Dordrecht
INAA and AAS of different products from sugar cane industry in Pakistan:
Toxic trace elements for nutritional safety
S. Waheed,* S. Rahman, K. P. Gill
Chemistry Division, Directorate of Science, Pakistan Institute of Nuclear Science and Technology, P. O. Nilore, Islamabad, Pakistan
(Received July 22, 2008)
Instrumental neutron activation analysis (INAA) have been used to determine As, Br, Hg, Sb and Se in combination with atomic absorption
spectrometry (AAS) as a complementary technique for the quantification of Cd and Pb in jaggery, brown sugar, white sugar and molasses. All
sugar cane products were collected from the local sugar cane industry of Pakistan. The highest concentration of these potentially toxic elements
was quantified in molasses; however, molasses together with jaggery, brown sugar and white sugar contains trace amounts of all of these elements.
Due to very low concentration of Cd it could only be detected in molasses. To evaluate the percentage contribution of these elements in the sugar
cane products to the weekly recommended values, intakes on weekly consumption of 100 g of each item have also been calculated which follow
the pattern Br>Se>Pb>Hg>As>Sb. The elevated Br contents may be attributed to the use of Br-containing chemicals for fumigation; however,
these contents are well within the tolerance levels. The estimated weekly intake of all toxic elements is very low indicating that sugar cane products
can be safely ingested as part of the diets.
Introduction
In Pakistan, the sugar industry is mainly dependent
on sugarcane and a nominal percentage of sugar-beet
production. Sugar cane crop is an important cash crop of
Pakistan and is grown on area more than one million
hectares. At the time of partition of India in 1947, the
country only had two sugar mills with total production
of 7.932 tons. By the end of 2006, the number increased
to 75, producing 3.6 million tons of sugar.
1,2
The main
reason for the success and development of this industry
can be attributed to the fact that almost all the products,
by-products and waste can be sold or used, apart from
the supporting climatic conditions of the country for
harvesting, cheap labour and low transportation charges
as most of the industries are located close to the
sugarcane cultivation sites. Globally, Pakistan is ranked
as fifth in terms of area, fifteenth by yield and twelfth by
recovery among the sixteen major producers of sugar by
sugarcane. Besides jaggery, brown sugar and white
sugar as the main products of this industry, molasses is
exported in large quantities to the international market.
Since molasses is used to produce ethanol, Pakistan
exported 234,000 metric tons of ethanol in the year
2007.
3
Nevertheless, the sugar industry is also beset with
many problems of environmental safety and pollution
concerns. Pakistan though being lucky to have gained
entry into international export markets also has to
strictly satisfy the World Trade Organization (WTO)
enforcement based on the quality and safety of all export
commodities. Since a number of chemicals including
lime, sulphur, phosphoric acid, bleaching powder,
* E-mail: swaheed161@gmail.com
polyelectrolyte, floatation aid, and decolorant are used in
the sugar making process, the end products and by
products have to be strictly monitored for any
contaminants. The quality of these chemicals varies
from mill to mill due to different type of processes, in
addition the use of the fertilizers, insecticides and other
chemicals also add to the inventory of the toxic
pollutants in the sugar products. The area of concern is
to ensure the quality of the sugar cane products and by-
products for dietary and environmental safety.
Trace elements play a major role in human health
and safety. Our daily dietary articles are the principal
pathways for the ingestion of potentially toxic element.
It is, therefore, important to monitor the level of these
toxicants in major food articles for their possible safe
intake. Therefore, a study was undertaken to
characterize the toxic trace elements in different produce
of the sugar cane industry of Pakistan to aid in
stipulating the pro-active human health and
environmental concerns. In addition the prospects of the
study would also help in heeding domestic safety
regulations and compliance for the sugar producers to
improve the quality of their products to satisfy the eco-
conscious international markets. Non destructive, highly
sensitive technique of instrumental neutron activation
analysis (INAA) with comparatively low detection
limits was used in this work to quantify toxic trace
elements in jaggery, brown sugar, white sugar and
molasses. Due to the low sensitivity of INAA for the
determination of Cd and Pb, atomic absorption spectro-
metry (AAS) has been utilized as a complementary
technique.