Determination Of Age Of Coral Reefs On Panikiang Island, Barru District, Spermonde Islands Through Measurement Activity 14C Using LSC (Liquid Scintillation Counting) Method. This research was using a sample of coral reefs taken from the Panikiang Island, Barru, Spermonde Islands. This research has been carried out by using sample preparation with physic and chemical. Sample preparation was done physically and chemically. Chemical preparation was carried out by using a mixture of NaOH with 30% H2O2 followed by a mixture of HClO4 with 30% H2O2, and finally with HCl solution to produce a clean sample with a weight reduction of 7.94%. Absorption of CO2 through reaction with HCl 10% and NH4OH as Carbosorb .produced K2CO3. The total carbon in the sample solution is 0.2496 gram sobtained through titration method.  Radiocarbon dating method based on the measurement of the specific activity of the samples obtained from the results of counts LSC (Liquid Scintilation Counter) Hidex 300 SL.The specific activity of coral sample is 14.68 ± 4.04 DPM/gC. Age of coral sample which were calculated from the specific activity were 342.04 ± 37.66 years

Arisandi, Arisandi

Maming, Maming

Noor, Alfian

English

Universitas Hasanuddin: e-Journals

Marina Chim. Acta, Vol. 2 (1), 20199DETERMINATION OF AGE OF CORAL REEFS ON PANIKIANG ISLAND,BARRU DISTRICT, SPERMONDE ISLANDS THROUGH MEASUREMENTACTIVITY 14C USING LSC (LIQUID SCINTILLATION COUNTING)METHODArisandi, Alfian Noor, MamingDepartment of Chemistry, Faculty of Mathematics and Natural Sciences, Hasanuddin University,Jl. Perintis Kemerdekaan Km.10, Makassar, Indonesia 90245*Corresponding author: arisandi013@gmail.comABSTRACTDetermination Of Age Of Coral Reefs On Panikiang Island, Barru District, Spermonde IslandsThrough Measurement Activity 14C Using LSC (Liquid Scintillation Counting) Method. This researchwas using a sample of coral reefs taken from the Panikiang Island, Barru, Spermonde Islands. Thisresearch has been carried out by using sample preparation with physic and chemical. Samplepreparation was done physically and chemically. Chemical preparation was carried out by using amixture of NaOH with 30% H2O2 followed by a mixture of HClO4 with 30% H2O2, and finally withHCl solution to produce a clean sample with a weight reduction of 7.94%. Absorption of CO2 throughreaction with HCl 10% and NH4OH as Carbosorb .produced K2CO3. The total carbon in the samplesolution is 0.2496 gram sobtained through titration method. Radiocarbon dating method based on themeasurement of the specific activity of the samples obtained from the results of counts LSC (LiquidScintilation Counter) Hidex 300 SL.The specific activity of coral sample is 14.68 ± 4.04 DPM/gC.Age of coral sample which were calculated from the specific activity were 342.04 ± 37.66 years.Keywords: Specific Activity, Coral Reef, LSC, Radiocarbon datingReceived: 10 April 2019, Accepted: 29 April 2019,    Published online: 21 May. 20191. INTRODUCTIONThe Spermonde Islands are one of themost important marine areas in SouthSulawesi. The Spermonde Islandsidentified ± 400,000 ha. The area of coralreefs are found in the waters of Indonesiaare more than 60,000 km2 and most ofthem found from eastern to westernIndonesia. There are 350 species of coralfound in Indonesia, 250 species of themare found in Spermonde Islands in a 150km2 coral reef area. The SpermondeIslands coral diversity levels are quite highbecause there are 78 genera and sub-genera, with a total of 262 species. Viewedfrom the level of coral spread, around 80%-87% are found in the outermost reefareas.Determination of age of dead coralreefs in a sea also has enormous benefits instudying the geographic of the sea coralorigin such as samples to trace and studythe establishment of a sector in coastalrock formations. Besides the determinationof age, coral reefs can also be used todetermine the apparent radiocarbon age ofthe sea [1].Marina Chim. Acta. 2 (1), pp.9-14, 2019MARINA CHIMICA ACTAJurnal Tiga Bahasa Tentang Kimia LautOpen Access Journall at : http//journal.unhas.ac.id/index.php/mcap-ISSN : 1411-2132e-ISSN : 2620-6145Marina Chim. Acta, Vol. 2 (1), 201910Determined the age of the coral reefsand growth rate of reef to determine thecharacteristics of the water such as anincrease in sea surface temperatures, oneof which caused by the El-Nino in theSeribu Island. Characteristics of the waterscan be identified through a decrease in therate of linear growth of coral reefs, whenEl-Nino occurs on a large scale as in 1997-1998 and 1982-1983. The decline in therate of linear growth is also caused byfactors of water condition that occur on asmall scale (local) as a result of increasedlevels of pollutants, nutrients andsedimentation [2].Determination age of the coral reefscan be known by measuring theradioactivity of the elements in the sampleand by measuring the age of the coral,information can be used to trace and studyrock formation on a coast and on theearth's surface, knowing the age of marinecoral samples, so that the history of theformation of the earth can be expressedmore clearly with the support of accuratedata [1].The last few years, scientists havedeveloped a liquid scintillation countingmethod for the measurement of total α andβ in environmental samples, becauseexisting methods (electrodepositionmethod) is quite complicated. Liquidscintillation counting method is now notonly used for the counting of low-energy βradiation, but can be used also for countingof α and β total. This method is known asLSC (Liquid scintillation Counting).Advantages compared with the previousmethod is a liquid preparation facilitatesample dissolved homogeneously, so thereis no effect of self-absorption. This methodcan detect 3H and 14C can also determine αand β the total at once, thereby saving time[3].Method of age determination using14C during chopping is done by liquidscintillation counter with C6H6, choppingC in the form of graphite with AMS(Accelerator Mass Spectrometry) andchopping CH4 with Mini Gas ProportionalSpectrometry. These methods are rarelyused in the determination of age becauseof the cost of equipment and materials torepair the sample is very expensive.Sample preparation is quite complicated,long and requires consideration ofadequate technical skills so as to studyhydrology especially uneconomical andinefficient, because only one sample canbe analyzed daily. The last two decadeshave started to develop CO2 absorptionmethod is better than previous methods[4].The application of the LSC (LiquidScintillation Counting) method through themeasurement of 14C activity indetermining the age of a material hasplayed an important role, not only in thediscovery of the age of ancient objects inthe of archeology, but also in determiningthe age of sediments, corals, shells, water,soil and others [5]. As research conductedby [6], at the Radiation ChemistryLaboratory of FMIPA Unhas, the LSCmethod was used in analyzing samples ofmarine corals originating from theSpermonde Islands in South Sulawesi.Several other studies on determining theage of coral reefs have also been carriedout, for example by [7], taking samplesaround the Spermonde Islands usingKarbosorb hydroxide using the LSCmethod through measurement results, it isknown that the age of Spermonde Islandscoral reefs is 403.61 years, but themajority of the beaches scattered in theSpermonde Islands do not have the data tosee the extent of the coastline of theMarina Chim. Acta, Vol. 2 (1), 201911Spermonde Islands. Therefore, in thisstudy will be conducted on PanikiangIsland, Barru Regency to collect age dataon coral reefs in the Spermonde Islands.2. MATERIAL ANDMETHODSamplingCoral sample taken at seawater nearone of the islands in the SpermondeArchipelago, which is in Langkai Island ata depth about 4-5 m. Langkai Islandlocated on coordinate S: 05o 01’ 47,055” E:119o 05’ 50,272”. Coral samples weretaken on the sea around the island in theSpermonde Islands, namely Langkai Islandat a depth of 4-5 m at coordinates 4 27'00 ''- 5 29'00 '' LS and 119 2'00 '- 119 33'00''BTPhisical and Chemical CleaningCleaning methods are designed toremove contaminating carbon sources thataccumulate both while the specimen is onthe sea floor and while it is stored on landafter collection. Water rinses andscrubbing with a brush remove sedimentfrom inside the coral and between thesepta. Samples are then immersed in a 1:1mixture of 30% H2O2 and 1N NaOH andultrasonicated for 15 minutes. However,this process often leaves abrownish/orange organic stain on theCaCO3. Quick dips (30 seconds to 2minutes) in a 1:1 mixture of 30% H2O2and 1N HClO4 effectively remove thisstain. After the dilute perchloric step,samples are rinsed thoroughly with cleandistilled water. For the second acid wash,pre-weighed samples are dipped into 6NHCl for 15–60 seconds followed by rinsesin two separate beakers of distilled H2O.After drying for several minutes in a 60 °Coven, the samples are cooled andreweighed to determine the percent ofsample removed. Samples are then crushedin an agate mortar and pestle to facilitatedissolution in the reaction flasks [8].Samples of coral reefs were washedin running water with brushed severaltimes followed by rinsing with aquadesuntil clean. After physical washing, a coralsample is placed in a container and dried.Chemical washing begins with immersionof coral samples into a mixture of 30%H2O2 and NaOH 1 N 50:50 in a 100 mLbeaker and ultrasonic for ± 10 minutes.Then the washing solution is separatedfrom the sample with occasional samplesbrushed and rinsed again with distilledwater (aquades) to remove black stainswhich are in the narrowest blemish of thesample. Furthermore, the coral reefsamples were soaked back in a mixture of30% H2O2 and 1% 50:50 HClO4 in a 100mL beaker for 30 seconds - 2 minutes. Thefinal process in chemical washing is asample of coral reefs soaked in 10 mL of10% HCl solution for 15-60 seconds andrinsing again with distilled water (aquades)repeatedly. Furthermore, coral reefsamples were dried in an oven at 105⁰Cuntil dry and weighed again to find out theweight % of the samples lost during thechemical washing process [8].Carbon Dioxide Absorption (CO2)Dried coral sample were transferred toflask that connected to a separation funnelas hydrochloric acid reservoir. Prior tocarbon dioxide absorption, the nitrogengas was streamed along the system.Solution of 10 % HCl was added by dropsto the sample until bubles formed(Fig.1).Gas is channeled into an impingercontains 40 mL ammonium hydroxide asMarina Chim. Acta, Vol. 2 (1), 201912carbosorb after passed acid trap and watertrap. The process was stopped when thegas not formed by adding the hydrochloricacid. Concentration of CO2 absorbed wasquantified from the difference of weightbefore and after absorption process. Thesame method is used to absorb CO2 fromMarble for use in the measurement of theBackgroundFigure 1. Design of absorption system ofcarbon dioxide from coralsampleDetermination of Total CarbonK2CO3 dissolved pipetted inErlenmeyer 10 mL to titration with 5 MHCl solution after the addition of a fewdrops of indicator MO until the colorchanges from brown to pink. Furthermore,pipette 10 ml of K2CO3 into a beaker foradded  BaCl2 10% solution until beprecipitation (saturated). Subsequently, theprecipitate and the filtrate was separatedused filtered, then the filtrate was pipettedinto Erlenmeyer 10 mL for titrated with 5M HCl solution with the addition of a fewdrops of indicator PP until the colorchanges from purple to clear.Counting Carbon-14Approximately 8 mL of sample orbackground mixture with 12 mLscintillator in 20 mL vial. The mixture washomogenated by shaking and saved fromlight exposure, and then lied on 20 mL vialplate tray. Counting the sample as protocolLSC Hidex 300 SL and it was counted at5-240 minutes in range.RESULT AND DISCUSSIONPhsycal and Chemical CleaningCoral sampel that have beenphysically and chemically cleaned lookedclean and white. The chemical cleaningremoved impurities and carbon source onthe surface up to 7,94 %. The result ofthese experiments are not much differentfrom the result of deep-sea coral samplecleanup was done by Adkins et al. 1 andMaming et al.6 The missing part of thesample is a natural contaminant thataccumulates over the coral reef waters anddissolved matrix surface.Counting Carbon-14The results of measurements of 14Cactivity measured on the instrument isexpressed in units of Count Per Minute(CPM) which shows the number of βparticles produced from 14C in coralsample in every minute, and the activity ofcoral sample is expressed in unitsDisintegration Per Minute (DPM) whichshows the actual number of atoms in the14C decays coral samples in every minute.The relationship between the value ofDPM and the value CPM is expressed as aform of efficiency in units of countingwhich stated Triple Double CoincidenceRatio (TDCR).Measurement of background was doneby the CO2 absorption using marble as asource of CO2 background. Marble is acarbon source with old age that isconsidered to contain carbon-14 with verylow activity. Determination of theoptimum time of counting was performedto determine the best time and the resultingDPM value and TDCR value stable as asign that the sample counting processrunning optimally. In 90-240 minutes,Marina Chim. Acta, Vol. 2 (1), 201913activity values of 14C ranging achievestability. The optimum time of countingsample and background are determinedbased on the figure 2. The optimum timeof counting is 120 minutes for sample andoptimum time of counting is 60 minutesfor background.Figure 2. Determination of CountingTime Optimum Sample andBackground Of Coral ReefDetermination of specific activity ofthe sample of coral reefs can known basedcounting from sample and background  atthe optimum time respectively 120 and 60minutes. The counting is done as much as7 times repetition, in order to obtain theaverage activity of the sample and thebackground can be seen in Table 2. Theaverage activity data is then used todetermine the value of the specific activityof samples of coral reefs.Table 2. Activity of 14C Sample andBackgroundSample BackgroundDPM DPM108,030106,520107,210106,030107,640106,430106,870104,690104,320103,370103,320102,800102,660101,920The specific activity of samples ofcoral reefs can be determined from thedifference between the results ofDisintegration Per Minute (DPM) ofsample and the results of DisintegrationPer Minute (DPM) background divided bythe total content of carbon in 8 mL ofsample were mixed with 12 ml ofscintillator. Determination of total carboncontained in the coral reef sample titrationmethod and gravimetric method. Bothmethods are very supportive in this study.Total carbon mass obtained on samples ofcoral reefs are shown in Table 3. The valueof the specific activity is indicated byDPM units per unit mass. Specific activitydata samples of coral reefs are shown inTable 3. The value of the specific activity(As) shows the number of atoms of 14Cthat decays every minute in one gram ofcarbon element.Table 3. The Specific Activity (As) ofCoral Reef Sample fromLangkai IslandDPMs DPMb DPMC-total(g)As(DPM/gC)As C-14 life107.962 103.297 3,655 0,2496 14,68 ±4,0415,30 ±0,1Age determination of coral sample isdetermined based on the specific activitiesthat have been obtained previously. Theage of coral  sample calculated from thespecific activity using ammoniumhydroxide as carbosorb was 342.04 ±37,66 years.4. CONCLUSIONSThe specific activity of coral  sampleusing ammonium hydroxide as carbosorbwas 14.68 ± 4,04 DPM/g C. The age ofcoral  sample calculated from the specificactivity using ammonium hydroxide ascarbosorb was    342.04 ± 37,66  years.0501001500 100 200 300DPMTime (minutes)background sampelMarina Chim. Acta, Vol. 2 (1), 201914REFERENCES[1] Yuliati, H., Akhadi, M., 2005,Radionuklida Kosmogenik UntukPenaggalan, Puslitbang KeselamatanRadiasi dan Biomedika Nuklir, Pusatradiasi Batam.[2] Arman, A. dkk., 2013, StudiPenentuan Umur dan LajuPertumbuhan Terumbu Karang terkaitdengan Perubahan Iklim EkstrimMenggunakan Sinar-X, Jurnal IlmiahAplikasi Isotop dan Radiasi, 9 (1): 1-10.[3]. Tjahaja, I.P., dan Mutiah, 2000,Metode Pencacahan Sintilasi Cair :Salah Satu Alternatif untukPengukuran α dan β Total dalamSampel Lingkungan, IndonesianJournal of Nuclear Science andTechnology, 1 (1): 31-46.[4] Satrio dan Abidin, Z., 2007,Perbandingan Metode SintesisBenzena dan Absorpsi CO2 UntukPenanggalan Radioisotop 14C, JurnalIlmiah Aplikasi Isotop dan Radiasi,Jakarta, 3 (1): 1-26.[5] Siregar, D. A., dan Soehaimi, A.,2009, Penarikhan Radiokarbon dalamPenentuan Aktivitas Tektonik Kuarterdi Sepanjang Aliran Sungai Opak danPantai Samas, Yogyakarta, JSDG,19(2): 117-126.[6]. Jauhari, Maming, 2014, Determinationof The Coral Age in SpermondeArchipelago Measurement 14CActivity Using LSC (LiquidScintillation Counting) Method,Marina Chemica Acta, 15(1): 13-20[7] Hartoko, D. A., Noor, A., Zakir, M.,dan Maming, Utilization of HydroxideCompound As CO2 Absorbent forMeasurement of Carbon-14 in CoralReef Sample From SpermondeArchipelago, Marina Chemica Acta,17(2), ISSN 1411-2132.[8] Adkins, J.F., Griffin, S., Kashgaria,M., Cheng, H., Druffel, E.R.M.,Boyle, E.A., Edwards, R.L., Shen,C.C. (2002)  Radiocarbon Dating ofDeep-Sea Corals. Radiocarbon. 44 (2): 567-580

DETERMINATION OF AGE OF CORAL REEFS ON PANIKIANG ISLAND, BARRU DISTRICT, SPERMONDE ISLANDS THROUGH MEASUREMENT ACTIVITY 14C USING LSC (LIQUID SCINTILLATION COUNTING) METHOD

Marina Chimica Acta

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DETERMINATION OF AGE OF CORAL REEFS ON PANIKIANG ISLAND, BARRU DISTRICT, SPERMONDE ISLANDS THROUGH MEASUREMENT ACTIVITY 14C USING LSC (LIQUID SCINTILLATION COUNTING) METHOD

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