COMPARATIVE DETERMINATION OF IRON IN DIFFERENT MILK PRODUCT USING THIOCAYANATE AND MODIFIED THIOCAYANATE

COMPARATIVE  DETERMINATION OF IRON IN DIFFERENT MILK PRODUCT USING  THIOCAYANATE AND MODIFIED THIOCAYANATE 

ABSTRACT

A comparative study of the determination of Iron in a variety of milk products was carried out using the thiocyanate and modified thiocyanate methods. A total of five milk products were studied. For each samples solution, 1.0ml of ammonium thiocyanate reagent 10% w/v was added to 5ml of the sample and mixed properly. It was determined by the thiocyanate method. While 0.5ml of ceric ammonium sulphate solution was added to the sample and mixed well, then 0.5ml of potassium thiocyanate was added, it was determined by modified thiocyanate method. The result were tabulated to compare . Differences in result was observed from the methods, and thiocyanate method was more closer to the standard values.

CHAPTER ONE

1.0       INTRODUCTION

Iron is a chemical element with symbol Fe (from Latin: Ferrum, ultimately from Ferre to bear or carry) and atomic number 26. It is a metal in the first transition series. It is by mass the most common element on earth, forming much of Earth’s outer and inner core. It is the fourth most common element in the crust its abundance in rocky plants like Earth is due to its abundance production by fusion in high-mass stars (Kideyber 2011).

Like other group eight (8) elements, iron exists in a wide range of oxidation states, -2 to +6, although +2 and +3 are the most common. Elemental iron occurs in meteoroids and other low oxygen environments, but is reactive to oxygen and water, fresh iron surface appears lustrous silvery-gray, but oxidize in normal  air to give hydrate iron oxides, commonly known as rust. Unlike the metals that form passivating oxide layers, iron oxides occupy more volume then the metal and thus Flake off, exposing fresh surfaces for corrosion, (science 2012).

Iron metal has been used since ancient times though copper alloys, which have lower melting temperature, were used over earlier  in human history. Pure iron is relatively soft, but is unobtainable by smelling. The material is significantly hardened and strengthened by impurities in particular carbon, from the smelting process, (Allen, et al.,1981).

Iron is a mineral that is naturally present in many foods, added to some food products and available as a dietary supplement. Iron is an essential component of hemoglobin, an erythrocyte protein that transfers oxygen from the lungs to the tissue, (Ross, et al 2014). As a component of myoglobin, a protein that provides oxygen to muscles, iron supports metabolism (Aggett P.Y, et al 2012). Iron is also necessary for growth, development, normal cellular functioning and synthesis of some hormones and connective tissue (Murray-Kolbe LE, et al 2010).

Dietary iron has two main forms: heme and non-heme (Ross et al 2014). Plant and iron-fortified foods contain non-heme iron only where as meat, seafood and poultry contain both heme and non-heme iron (Aggett Py,  2012). Heme iron which is formed when iron combines with protoprohyrin 1x.

Most of the 3 to 4 grams of elemental iron in adults is in hemoglobin (Aggett Py,  2012). Much of the remaining iron is stored in the form of Ferritin or hemosiderin Ca degradation product of Ferritin in the liver, spleen, and bone marrow or is located in myoglobin in muscle tissue (national academy press, 2001). Humans typically loss only small amounts of iron in urine, faces, the gestrointestinal tracts and skin. Losses a greater in menstruating woman because of blood loss. Hepeidin, a circulating peptide hormones, is the key regulator of both iron absorption and the distribution of iron throughout the body, including in plasma (science2012).

Milk is a pale liquid produced by the mammary glands of nutrition for infant mammals, before they are able to digest other food (Pehisson et al., 200). As an agricultural product, milk is extracted from non-human mammals during or soon after pregnancy. Dairy farms produced about 730million tonnes of milk in 2011, (Global market analysis 2012), from 260 million dairy cows, (world dairy cow numbers 2014). India is the world’s largest producer of milk and is the  leading explorer of skimmed milk powder (dawn comp) a natural source of humans of all ages that is derived by definition produce milk, but cows milk dominate commercial production. In 2011, FAO estimate 85% of all milk worldwide was produced from cows, (Gerosa and Skoct 2012). Aside from cow, many kinds of livestock provide milk used by humans for dairy products. These are buffalo, goat, sheep, camel donkey, horse, reindeer and yak. The first four respectively produced about 11%, 2% 1.4% and 0.2% of all milk worldwide in 2011.

The composition of milk differ widely among species. Factors such as the type of protein; the proportion of protein, fat and sugar; the levels of various vitamins and minerals, and the strength of cured are among those that may vary. For example: human milk contains, an average, 1.1% protein, 4.2% fat, 7.0% lactose (a sugar) and supplies 72 Kcal of energy per 100 grams. Cow’s milk average, 3.4% protein, 3.6% fat and 6.4% lactose, 0.7% minerals and supplies 66KCal of energy per 100 grams. Milk is an emulsion or colloid of butter fat globules within a water-based fluid that contains dissolved carbohydrates and protein aggregates with minerals (Rolf Jost 2002).

1.2       AIM AND OBJECTIVE OF THE STUDY

1. To determining the level of iron present in milk.
2. To compare the determination of iron in milk using thiocyanate and modified thiocyanate method
3. To review the fundamental concepts of quantitative spectrophotometric analysis.

CHAPTER TWO

LITERATURE REVIEW

2.1       HISTORY OF IRON

Iron has been worked, or wrought, for millennia. However, iron objects of great age are much rarer than objects made of gold or silver due to the ease with which iron corrodes.(Week 1968) Beads made from meteoric iron in 3500 BCE or earlier were found in Gerzah, Egypt by G. A. Wainwright.(Week 1968) The beads contain 7.5% nickel, which is a signature of meteoric origin since iron found in the Earth’s crust generally has only minuscule nickel impurities. Meteoric iron was highly regarded due to its origin in the heavens and was often used to forge weapons and tools/(Week 1968) For example, a dagger made of meteoric iron was found in the tomb of Tutankhamun, containing similar proportions of iron, cobalt, and nickel to a meteorite discovered in the area, deposited by an ancient meteor shower.(Bryce 2007) Items that were likely made of iron by Egyptians date from 3000 to 2500 BCE. Iron had a distinct advantage over bronze in warfare implements. It was much harder and more durable than bronze, although susceptible to rust. However, this is contested. Hittitologist Trevor Bryce argues that before advanced iron-working techniques were developed in India, meteoritic iron weapons used by early Mesopotamian armies had a tendency to shatter in combat, due to their high carbon content.(Bryce 2007).