Qualitative and Semi Quantitative Analysis of Sample from Kolosh Formation in Kurdistan Region North of Iraq

A sample from Kolosh formation nearby Hizop small village near Kaniwatman area in Kurdistan region was taken for the purpose of conducting qualitative and semi-quantitative analysis for most of elements that constitute the sample. Initial simple physical examination shows that the sample contains a percentage of iron (III) oxide. Three parts of the sample were allowed to react with three in excess concentrated hydrochloric, nitric and sulphuric acids separately. The reaction with HCl gives deep yellow solution, with HNO3 and with H2SO4 gives colorless solution. Most of the transition elements in the periodic table were excluded for the absences of the characteristic colors of their ions in solutions. Analysis shows that the percent of total organic carbon (TOC) in the sample was 5.3%, for silica was 26.9% and for iron was 2.5%. The percentages of missing weight from the samples after their reaction with sulphuric, nitric and hydrochloric, acids were, 42.3%, 44.3% and 48.7% respectively. The group’s qualitative analysis for Kolosh sample showed a measureable presence of iron, silicon, carbon and calcium compounds. The presence was very low for other elements compound like barium, aluminum, lead and thallium. The aim of this work is a qualitative and semi quantitative analysis for probable existence of some elements compound in Kolosh formation mineral. Key Wards: Kolosh formation, Shale mineral, Calcium carbonate, Calcium sulphate, Silica, Total organic carbon (TOC). Qualitative and Semi Quantitative Analysis of Sample from Kolosh Formation in Kurdistan Region North of Iraq Tahir Ahmad Tahir and Omer Fikrat Bahjet 57 Vol: 13 No: 3 , July 2017 DOI : http://dx.doi.org/10.24237/djps.1303.194B P-ISSN: 2222-8373 E-ISSN: 2518-9255 ليلحت قارعلا لامش ناتسدرك ميلقا يف يجولويجلا شولوك نيوكت نم جذومنل يمك هبش و يفصو رــهاط دــمحأ رـهاط 1 و هب تركف رمع ــــ تج 2 1،2 ةايحلا مولع مسق مولعلا ةيلك ليبرا ةعماج


Introduction
Kolosh formation was firstly described by Dunnington [1] in Kolosh area northern Koisanjaq city, northern Iraq.It consists of black shale's , fine sandstones, fragments of various grain size of green rock, other minerals, especially quartz and calcite.The ratio of clay to other minerals is variable. [2]Black shale is one of meager constituent of Kolosh formation [3].
According to literature survey, different definitions for black shale were mentioned. [9,4,5,6].It is a dark-colored mudrock containing organic matter, silt and clay-size mineral grains that accumulated together.Vine [7] pointed out the compositional variations included in this greater than 10 for Mo [8] .Such increased concentrations of Ag, Mo, Zn, Ni, Cu, Cr, V, and less commonly Co, Se, and U elements are apparent features of only some black shale. [9]The enriched values are of controversial origin, having been alternatively attributed to input from hydrothermal fluids during or after sedimentation or to slow accumulation from sea water over long periods of sedimentation. [10]Typical levels for Fe in sedimentary rocks are given by Williamson [10] as: limestone 0.33%; sandstone 0.98%, shale 4.7%, and banded iron formation 28%.Almost all Iron (III) oxides Fe2O3 are ferromagnetic, which means they all attract to magnets.The organic material that gives black shale its distinctive characteristics is derived from living things.Since black shale has accumulated throughout the entire evolution of life on the Earth, the composition of the organic matter in black shale should reflect evolutionary development of living things at the time the shale was deposited.
In soils and sediments, there are three basic forms of carbon that may be present.They are: (1)   elemental C, (2) inorganic C, and (3) organic C. The quality of organic matter in sediments is critical to the partitioning and bioavailability of sediment-associated contaminants.For example, Talley et al., 2002 [11] , demonstrated that although the majority of PAHs (Poly-Aromatic Hydrocarbon) in a dredged sediment were found preferentially on coal-derived particles, the PAHs on the clay/silt sediment fraction were more mobile and available, and thus potentially of greater concern.serious groups of pollutants due to their high toxicity, abundance, and ease of accumulation from various plants and animals.It has been accepted that heavy metals can exist in the environment deriving from a variety of natural and anthropogenic sources.The phenomena of erosion, acidification, and weathering processes have brought input of these metals into the environment in a natural way.According to Idris [12] , the natural occurrence of heavy metals in aquatic environments and their movement through the hydrocycle in addition to the inputs from anthropogenic activities reflect their ubiquity and complexity.Meanwhile, human activities also contribute to the existence of these metals such as industrial processes, agricultural and aquaculture activities, domestic wastes, and emission from vehicles [13] .
The present study is for qualitative and quantitative analysis of some possible elements present in geological Kolosh formation mineral.The same experiment was proceeded using regular iron bar but no particles attracted to it, which confirmed the presence of Fe2O3 as it has ferromagnetic properties.

Materials and Equipment
B-Samples of Kolosh rocks were crashed to fine powder in porcelain pestle and mortar with unglazed grinding surfaces, and then sifted through nylon mesh 3microne size before further test.

C-Reaction with Acids:
Three samples of Kolosh mineral each of three grams (3gm) were allowed to react with excess of concentrated sulphuric, nitric and hydrochloric acid separately for overnight to assure complete reaction between the acids and Kolosh samples.The mixtures were filtered, and the precipitate washed several times to remove any trace of the acids, then dried at 105 0 C for six hrs., cooled in a dissector and weight as shown in table (1).The filtrates were kept for further test.

D -Determination of Silica
A sample of one gram of sulphurated Kolosh mineral was thoroughly mixed with different weights of sodium fluoride NaF as shown in table (2).

Silica Calculation
Silica present in sulphureted Kolosh were calculated through the following chemical equations: This process was repeated three times for same precipitate to ensure that more heating would not cause further loss in the weight of the precipitate.The percentage of TOC in the sample was (5.3%).

F -Determination of Iron
Two grams of iron wool was dissolved in excess of concentrated nitric acid.No residue or precipitate was left after dilution and filtration of the reactants.The filtrate was diluted to 250 ml in volumetric flask.Six serial volumes of this solution were diluted to 50 ml.in volumetric flask as showed in table 3 Solution containing 250 mg/mL of potassium thiocyanate was prepared.One mL of this solution was added to aforementioned six different concentrations.
The Fe 3+ ions react with SCN − ion to form a blood-red coloured complex as shown in the following chemical equation: obeys Beer's law [14] For determination of iron concentration in Kolosh mineral, 5 g sample of powdered Kolosh

G -Qualitative Analysis of Elements
Experiments of analysis have been carried out with a view to obtain optimum results for qualitative determination of some elements that are present in measurable concentration and qualitative determination of other elements, which are present in trace or negligible concentrations in Kolosh mineral, that was due to lack of sophisticated equipment in our department.Table (3) shows the percent of some measure elements were represented in Kolosh mineral.
Samples of Kolosh mineral were digested and extracted in concentrated hydrochloric, nitric and sulphuric acids.The extracted solutions then reacted with different reagent for qualitative identification.
G-1-For group one elements in qualitative analysis (i.e.Ag, Hg and Pb elements) [15] , post the reaction of Kolosh mineral with hydrochloric acid, all Ag, Hg and Pb compounds present in

Results
The results of Kolosh samples reaction with different concentrated acids are summarized in table (1).The equivalent weights of NaF/g to the weight of sulphureted Kolosh sample /g are summarized in table (2). Table ‫القريبه‬ ‫الصغرى‬ ‫هيزوب‬ ‫منطقة‬ ‫في‬ ‫الواقع‬ ‫كولوش‬ ‫تكوين‬ ‫من‬ ‫عينه‬ ‫اخذ‬ ‫تم‬ ‫اقليم‬ ‫في‬ ‫وتبان)‬ ‫(كاني‬ ‫الخام‬ ‫ان‬ ‫االولي‬ ‫الفيزائي‬ ‫الفحص‬ ‫من‬ ‫تبين‬ ‫للعينه.‬‫المكونه‬ ‫العناصر‬ ‫الغلب‬ ‫كمي‬ ‫شبه‬ ‫و‬ ‫نوعي‬ ‫تحليل‬ ‫اجراء‬ ‫لغرض‬ ‫كردستان‬ ways that these variations can be used to study black shale.Most shale that immediately meets this color criterion contains 1% or more organic carbon; 2-10% is a common range.Few shale contain more than 20% organic carbon.Pyrolysis yields variable amounts of liquid and gaseous hydrocarbons, the amount depending in part on the nature of the original organic material and in part on subsequent burial history.Black shale units may have beds enriched in metals by factors greater than 50 for Ag element, for example, and Inorganic carbon forms are derived from geologic or soil parent material sources.Inorganic carbon forms are present in soils and sediments typically as carbonates.The two most common carbonate minerals found in soils and sediments are calcite (CaCO3) and dolomite [CaMg(CO 3 ) 2 ] although other forms may be present (e.g., siderite, FeCO 3 ) depending on where the soils were formed or where the sediment source was located.It should be noted that Qualitative and Semi Quantitative Analysis of Sample from Kolosh Formation in some extent, dolomite, may also be present in soils and sediments due to agricultural input (i.e., liming practices).Organic carbon forms are derived from the decomposition of plants and animals.In soils and sediments, a wide variety of organic carbon forms are present and range from freshly deposited litter (e.g., leaves, twigs, branches) to highly decomposed forms such as humus.In addition to the naturally-occurring organic carbon sources are sources that are derived as a result of contamination through anthropogenic activities.The spills or releases of contaminants into the environment increase the total carbon content present in the soil or sediment.Heavy metals are one of the most poisonous and a-The Kolosh formation sample was collected from Hizop small village near Kaniwatban area, north Suliamani city, Iraq b-All reagents and solvents used were available commercially and were used without further purification unless indicated otherwise.c-All the glassware were washed with 0.1 M HCl (Washing solution) and properly rinsed with distilled water and dried before use.d-Spectrophotometer model T80pg instrument, wavelength 200 -1000 nm were used for absorbance reading at λmax = 460 nm.Vol: 13 No: 3 , July 2017 DOI : http://dx.doi.org/10.24237/djps.1303.194BP-ISSN: 2222-8373 E-ISSN: 2518-9255 Procedure A-Simple Physical Test Strong magnet bar was introduced to Kolosh mineral debris before it crushed to fine powder.Many particles of dark brown color were stick to the bar, which indicate the presence of Fe2O3 particles within the mineral.
--------------------------------------------Referring to figure(1), the plot shows that 1.3 g of NaF was enough to equate and react with all silica present in the sample.According to equation (3), four moles of NaF react with one mole of SiO2.Molecular weight of NaF = 42g/mole, for SiO2 = 60.1g/mole,Therefore 1.3g of NaF = (1.3/42) = 0.031 moles Number of SiO2 moles in sulphureted Kolosh = (0.031x1)4 = 7.75x10 -3 7.75x10 -3 x 60.1 = 0.446 g of sulphureted Kolosh Kolosh sample lost 27% of its original weight after its reaction with H2SO4 (conc.),Therefore: (0.466 x 100) / 27 = 1.73g original weight of the sample Assuming that SiO2 was not affected by initial reaction of the sample with H2SO4 (conc.), the percentage of SiO2 in Kolosh mineral: (0.466x100)/ 1.73 = 26.9%Percentage of reacted material at the initial reaction of the sample with H2SO4 (conc.)= 42.3%Percentage of reacted silica in the sample with HF = 26.9%Percentage of the remaining material, = 9.8% which is mostly sulphates that not reacted with hydrofluoric acid E -Determination of Total Organic Carbon (TOC) Kolosh sample includes inorganic sources of carbon such as carbonates and most notably calcite, dolomite, and siderite.These minerals react with acids, generating carbon dioxide and corresponding salt.Thus, the determination of total organic carbon (TOC) in Kolosh sample starts by reacting almost 20g of the sample with excess concentrated nitric acid, then concentrated hydrochloric acid to change all inorganic carbon component of the sample to soluble nitrates or chlorides which were discarded later by filtration.The precipitate was thoroughly washed with distilled water and dried at 120 0 C for six hours, then cooled in desiccator for overnight.Precisely seven grams of the dry, cooled precipitate was heated for six hours in crucible by naked flames of two torches, one beneath, the other was above the crucible so that the naked flames easily touched all parts of the precipitate in order to burn and maintain the oxidation of any organic carbon particles to carbon dioxide.The color of the Qualitative and Semi Quantitative Analysis of Sample from Kolosh Formation in from dark olive green (fig.2-A) to yellow-creamy color (fig.2-B) as shown in figure (2).The precipitate was cooled in desiccator for overnight, and then its weight was recorded.

[
near as possible to 15 minutes after adding thiocyanate, the absorbance at wavelength of 460 nm for each coloured solution was measured using colorimeter.The absorbance of each six different concentrations of the solutions were measured, plot of Abs.versus complex concentration was drawn as shown in figure(3).The line of best fit for the data points goes through the origin, because absorbance must be zero when Fe 3+ concentration is zero.The plot confirms that the dilute deep blood red colored solution of complex [Fe(NCS)(H2O)5] 2+

4 
mineral was allowed to react with excess concentrated nitric acid and left over night for reaction completion.The reactants mixture was filtrated and the filtrate was diluted to 250mL in volumetric flask (Solution A).One mL of Kolosh solution (A) and one mL of potassium Vol: 13 No: 3 , July 2017 DOI : http://dx.doi.org/10.24237/djps.1303.194BP-ISSN: 2222-8373 E-ISSN: 2518-9255 thiocyanate solution was diluted to fifty mL in volumetric flask (Solution B).The absorbance of new colored solution was measured at λ = 460nm.Iron Calculation According to straight line equation Y = mx + b Our spread sheet gives: Y = 0.0843 X Where Y is absorbance and 0.0843 is the slope of the line.The absorbance of the unknown concentration of Kolosh solution Y= 0.420 Substituting Y value in equation: Y = 0.0843 X X = 0.420 / 0.0843 = 4.98 In figure (3), Y is multiplied by 10 -Y = 4.98 x 10 -4 g / mL, the concentration of iron in one mL of Kolosh solution The concentration of iron in 250 mL solution = (250/1) * 4.98 x 10 -4 = 1245 x 10 -4 g Percentage of Iron in Kolosh mineral = [(1245 x 10 -4 *100) / 5] ≈ 2.5%