Measurement uncertainty of ester number, acid number and patchouli alcohol of patchouli oil produced in Yogyakarta

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1 Measuement uncetainty of este numbe, acid numbe and patchouli alcohol of patchouli oil poduced in Yogyakata Reni Banowati Istiningum, Azis Saepuloh, Widatul Jannah, and Didit Waskito Aji Citation: AIP Confeence Poceedings 183, (017); View online: View able of Contents: Published by the Ameican Institute of Physics Aticles you may be inteested in Impoving the quality of patchouli oil by adsoption pocess using sufactant modified of natual zeolite AIP Confeence Poceedings 183, (017); / An analysis of leaning pocess based on scientific appoach in physical chemsity expeiment AIP Confeence Poceedings 183, (017); / Utilization of natual indicatos fo boax identification in the Indonesian tofu AIP Confeence Poceedings 183, (017); / Physicochemical of pillaed clays pepaed by seveal metal oxides AIP Confeence Poceedings 183, (017); / Phenolic emoval using phenylamine modified montmoillonite AIP Confeence Poceedings 183, (017); / Cetyltimethyl ammonium bomide-mg/al hydotalcite fo emoval phenol in wate AIP Confeence Poceedings 183, (017); /

2 Measuement Uncetainty of Este Numbe, Acid Numbe and Patchouli alcohol of Patchouli oil Poduced in Yogyakata Reni Banowati Istiningum 1,a), Azis Saepuloh 1, Widatul Jannah 1, Didit Waskito Aji 1 1 Chemical Analysis Depatment, Islamic Univesity of Indonesia a) Coesponding autho: eni_banowati@uii.ac.id Abstact. Yogyakata is one of patchouli oil distillation cente in Indonesia. he quality of patchouli oil geatly affect its maket pice. heefoe, testing quality of patchouli oil paametes is an impotant concen, one though detemination of the measuement uncetainty. his study will detemine the measuement uncetainty of este numbe, acid numbe and content of patchouli alcohol though a bottom up appoach. Souce contibuto to measuement uncetainty of este numbe is a mass of the sample, a blank and sample titation volume, the mola mass of KOH, HCl nomality, and eplication. While the souce contibuto of the measuement uncetainty of acid numbe is the mass of the sample, the sample titation volume, the elative mass and nomality of KOH, and epetition. Detemination of patchouli alcohol by Gas Chomatogaphy consides the souces of measuement uncetainty only fom epeatability because efeence mateials ae not available. INRODUCION Patchouli Oil is Indonesia's main expot commodities poduced by the distillation of patchouli leaves (Pogostemon cablin Benth). In 01, Indonesia poduced,648 tons of patchouli oil that meets 90% of the wold demand of patchouli oil. Yogyakata is one of patchouli oil distillation cente and poduced 3 tons of patchouli oil in 01 [1]. he quality of patchouli oil geatly affect the maket pice. Accoding to SNI , thee ae some patchouli oil quality equiements that must be met including the este and acid numbes but the most decisive paamete is patchouli alcohol content. he ISO 3757: 00 equiement of patchouli alcohol content is 7-35% while based on SNI patchouli alcohol content is at least 30%. Seveal studies have been done to incease patchouli alcohol content though engineeing in the distilling pocess o teatment afte distillation. Patchouli oil puification has also been done in vaious ways such as adsoption using bentonite[], activated cabon [3] and chelation method [4]. Paametes which ae also impotant is the numbe of este and acid. Este numbe is an amount of mg KOH equied to saponificate estes contained in one gam of fat o oil. he geate the numbe, the highe este content of este in the oil sample. While the acid numbe indicates the numbe of mg of KOH used to neutalize the fee fatty acids in one gam of oil samples. Fee fatty acids in the oil sample is the esult of the hydolysis eaction between the oil and wate duing the teatment pocess. Based on SNI [5], maximum numbe este and acid value successively ae 0 and 8 mg KOH/g. Some eseach aimed to impove the quality of patchouli oil have been done but not many eseaches ae conducting a study to impove the quality of patchouli oil though the analytical methods used appoach. A eliable method of analysis has also become a detemining facto in the quality of patchouli oil especially patchouli oil poducts with expot quality. In Indonesia, the test method of patchouli oil have been set nationally though the SNI Intenational Confeence on Chemisty, Chemical Pocess and Engineeing (IC3PE) 017 AIP Conf. Poc. 183, ; doi: / Published by AIP Publishing /$

3 he valid test data must be accompanied by an uncetainty measuements value that show iegulaities that occued duing testing. A paamete associated with the esult of a measuement, that chaacteizes the dispesion of the values that could easonably be attibuted to the measuand [6]. In geneal, pocedues ae based on a component-by-component ( bottom-up ) appoach o on a top-down appoach using data fom collaboative tials, poficiency studies, validation studies o inta-laboatoy quality contol samples, o a combination of such data [7]. Bottom-up appoach povides valuable infomation on the souces of eos that can be impoved. But the esults can vay depending on the estimation made. he top down appoach uses pefomance data fom collaboatively studied and validated standad methods. his appoach may esult in highe measuement uncetainties, as it is based on epoducibility data. his study was conducted to estimate measuement uncetainty of este, acid numbe and patchouli alcohol content of patchouli oil obtained fom thee aeas in Yogyakata, namely Sandaan, Ngaglik and Pakem by bottom up appoach. EXPERIMENAL MEHODS Este Numbe: A 4 ± 0.05 g sample of patchouli oil and 5 ml of 0.5 N KOH in ethanol is fed into a 50-mL ound bottom flask containing boiling stones. hen the solution was efluxed fo 1 hou until the solution is boiling. he efluxing solution allowed to stand until cool, then was added phenolphthalein indicato. he solution is then titated with 0.5 N HCl which has been standadized with g Na CO 3 until a pink colo disappea. he same teatment is done to the blank by eplace patchouli oil with ethanol. his pocedue was eplicated seven times. Acid Numbe: A 4 ± 0.05 g of patchouli oil sample is dissolved in 5 ml neutal ethanol. hen the solution was added phenolphthalein indicato. he solution was titated with 0.1 N KOH which has been standadized with g potassium hydogen phthalate until the solution emains faintly pink. his pocedue was eplicated seven times. Patchouli alcohol content: patchouli alcohol is detemined by using Gas Chomatogaphy with opeating conditions: phenyl methyl siloxane capillay column, helium as mobile phase, column oven tempeatue of 60 C, injection tempeatue of 00 C, a pessue of 36.1 kpa, the oven tempeatue pogam 10 C/min with a stating tempeatue of 60 C and a final tempeatue of 300 C and the detecto was FID. Detemination of patchouli alcohol peak and etention time wee done by Gas Chomatogaphy-Mass Spectomety. RESULS AND DISCUSSION Uncetainty measuement was pefomed to estimate the value of which may be lost o gained fom the actual values. hee ae two types of uncetainty, namely uncetainty of type A and type B. ype A uncetainty is method of evaluation of uncetainty by the statistical analysis of seies of obsevations while type B uncetainty is method by means othe than the statistical analysis of seies of obsevations. Estimation of measuement uncetainty with a bottom-up (step by step) appoach is done in stages as follows [6]: Specify measuand Specification of the measuand equies both a clea and unambiguous statement of what is being measued, and a quantitative expession elating the value of the measuand to the paametes on which it depends. All of this infomation should be in the Standad Opeating Pocedue (SOP). Identify uncetainty souces Souces contibuto to measuement uncetainty can be identified by making a cause and effect diagam (Ishikawa diagam). hough this diagam, it can be seen the elationship of the contibutos to the uncetainty and to pevent double counting. Quantify uncetainty components Quantifying the uncetainty aising fom these souces. his can be done by evaluating the uncetainty aising fom each individual souce and then combining them. Calculate combined uncetainty All uncetainty contibutions must be expessed as standad uncetainties, that is, as standad deviations. he next stage is to calculate the combined standad uncetainty Specify measuands he measuand is defined as the concentation of este, acid dan patchouli alcohol in patchouli oil and is deived fom these Equation:

4 EN M V - V N/ m (1) b whee EN is este numbe (mg KOH/g), M is molecula weight of potassium hydoxide, 56.11, V b is volume of 0.5 N hydochloic acid consumed in the blank test (ml), V is volume of 0.5 N hydochloic acid consumed in the actual test (ml), N is exact nomality of the hydochloic acid, m is weight of the substance taken fo the test (g). AN M V N/ m () whee AN is acid numbe (mg KOH/g), M is molecula weight of potassium hydoxide, 56.11, V is volume of 0.1 N potassium hydoxide consumed in the actual test (ml), N is exact nomality of the potassium hydoxide, m is weight of the substance taken fo the test (g). A PA (%) p 100 (3) A whee PA is patchouli alcohol content (%), A p is peak aea of patchouli alcohol, A is total peak aea total peak aea of othe component in patchouli oil. Identify uncetainty souces o constuct cause and effect diagam (Ishikawa diagam), it equied infomation fom pocedues and equations fom analytical method 8. he cause and effect diagam of este and acid numbe shown in Fig.1 and Fig.. he chomatogaphy method has contibution of uncetainty fom the sepaation, fom the detection (the wavelength, and fom the integation. Although a moe detailed uncetainty calculation is possible, it is not pacticable. he uncetainty of chomatogaphic sepaation of fom is chaacteized by its oveall epeatability o epoducibility expessed as elative standad deviation [9]. M KOH V b V b m sample V N HCl m Na CO 3 M Na CO 3 Replication Este Numbe FIGURE 1. Cause and effect diagam of este numbe

5 M KOH V b Replication m sample V N NaOH m KHP M KHP Acid Numbe FIGURE. Cause and effect diagam of acid numbe Quantification of uncetainty components Standad uncetainty detemination of este and acid numbes ae based on factos that ae consideed to contibute to the measuement uncetainty that can be seen fom the cause and effect diagam in Fig.1 and Fig.. he main factos that contibuted to the uncetainty of the values ae: Mass (m sample) Mass standad uncetainty ((m)) is the type B uncetainty. he uncetainty fom analytical balance deived fom the mass weighing toleance on the cetificate (independent paamete calibation, s) divided by the ectangula distibution. ( m) ( cal.) s 3 (4) Volume Volume standad uncetainty ((V)) of buet is type B uncetainty. It is composed of the independent paametes calibation (cal.) and uncetainty of tempeatue (). he (cal) is deived fom independent paametes calibation (s) devided by the tiangula distibution while the () uncetainty is deived fom the influence of the tempeatue on the themal expansions of liquid and volumetic device. s ( cal.) 6 V ( ) 3 (5) (6) ( V ) (cal) () (7) whee V is volume of titation, is expansion coefficient of wate ( o C -1 ), and is tempeatue diffeence of actual measuement fom 0 o C. he (V) then calculated with Eq.7. Mola mass (M ) he mola mass standad uncetainty is type B uncetainty. he uncetainty in the mola mass of compound can be detemined by combining the uncetainty in the atomic weights of its constituent elements (x 1, x,,x n ). A table of atomic weights including uncetainty estimates is published by IUPAC in the Jounal of Pue and Applied Chemisty [10]. he standad uncetainty fo each element is ectangula distibution and is calculated by dividing the value of element uncetainty by 3. he standad uncetainty (M ) is a squae oot of the sum of the squaes of the contibutos: M ) (x ) (x )... (x ) (8) ( 1 n

6 Nomality Uncetainty of nomality (type B uncetainty) is detemined fom standadization pocedues with pimay standad compound. Contibutos of nomality uncetainties include pimay standad mass (Eq. 4), mola mass of pimay standad (Eq. 8), and volume titation (Eq.7). he combined uncetainty of nomality then calculated by the following equation: c( N) N ( m) m ( M M ) ( V ) V Replication he standad uncetainty fom epeatability expeiments ((Rep)) is is quantified in tems of the elative standad deviation (RSD) of the measued values 7. SD (Re p) (10) x whee SD is standad deviation of measued value, x is aveage of measued value. he uncetainty contibution of este numbe and acid numbe fo thee sample of patchouli alcohol summaized in able 1 and able. he uncetainty of eplication in patchouli alcohol detemination by GC is shown in able 3. Fom Fig. 3 it can be concluded that the highest contibution to the uncetainty is a nomality of HCl. his suggests that the standadization pocedue has a high andom eo. heefoe, to impove the eliability of the este numbe test can be focused on the volume of HCl when standadization. While the highest contibution to uncetainty in the detemination of the acid numbe is a eplication shown in Fig 4. his can be due to biases in the detemination of the titation end point of the patchouli oil sample. ABLE 1. Uncetainty contibution of este numbe Souce of contibution Value Standad Relative standad Unit (x) uncetainty (μ) uncetainty (μ/x) Patchouli oil fom Pakem Mass, (m) g V b, (V b ) 18. ml V, (V ) 17. ml M KOH, (M ) g/mol Nomality of HCl, (N) 0.59 N Replication, (Rep) Patchouli oil fom Ngaglik Mass, (m) gam V b, (V b ) 18. ml V, (V ) 16.8 ml M KOH, (M ) g/mol Nomality of HCl, (N) 0.59 N Replication, (Rep) Patchouli oil fom Sandaan Mass, (m) gam V b, (V b ) 18. ml V, (V ) 17.0 ml M KOH, (M ) g/mol Nomality of HCl, (N) 0.59 N Replication, (Rep) (9)

7 (a) (b) (c) FIGURE 3. Contibution (%) of each souce to uncetainty measuement of este numbe of sample fom (a) Pakem, (b) Ngaglik, (c) Sandaan he only souce of uncetainty in patchouli alcohol detemination by GC is eplication. his is because thee ae no available standad compounds fo patchouli alcohol and the lack of infomation about the validation method. Uncetainty eplication fo patchouli alcohol content fo thee samples ae shown in able 3. able 3. shows that the

8 highest uncetainty is shown by patchouli oil samples fom Sandaan. his is because of fom seven epetitions, two wee pefomed on diffeent days, so it can be efeed to as the intemediate pecision but the othe samples wee pefomed in the same day. ABLE. Uncetainty contibution of acid numbe Souce of contibution Value Standad Relative standad Unit (x) uncetainty (μ) uncetainty (μ/x) Patchouli oil fom Pakem Mass, (m) gam x x 10-5 V, (V).09 ml.05 x x 10-3 M KOH, (M ) g/mol x x 10-6 Nomality of HCl, (N) 0.08 N.30 x x 10-3 Replication, (Rep) x x10 - Patchouli oil fom Ngaglik Mass, (m) gam x x 10-5 V, (V).14 ml.05 x x 10-3 M KOH, (M ) g/mol x x 10-6 Nomality of HCl, (N) 0.08 N.30 x x 10-3 Replication, (Rep) x x 10 - Patchouli oil fom Sandaan Mass, (m) gam V, (V).19 ml M KOH, (M ) g/mol Nomality of HCl, (N) 0.08 N Replication, (Rep) ABLE 3. Replication uncetainty contibution of patchouli alcohol Sample Standad Value Relative standad Unit uncetainty (x) uncetainty (μ/x) (μ) Pakem x Ngaglik x Sandaan x Calculate combined and expanded uncetainty In ode to detemine the combined uncetainty, the elative standad uncetainty must be squaed with the peviously divided by its value. Uncetainty combined to estes and acid numbes wee calculated with Eq.11 and Eq.1. he expanded uncetainty U(c) is obtained by multiplying the combined standad uncetainty with a coveage facto of coesponding to level of tust of 95%. he combined and expanded uncetainty ae shown in able 4. he epot of uncetainty of each paametes of patchouli oil is shown in able 5. c( EN) EN (11) c( AN ) AN ( m) m ( M M ( m) m ) ( M M ( Vb ) V b ) ( V V ( V ) V ) ( N) N ( N) N (Re p) (Re p) (1)

9 (a) (b) (c) FIGURE 4. Contibution (%) of each souce to uncetainty measuement of acid numbe of sample fom (a) Pakem, (b) Ngaglik, (c) Sandaan

10 ABLE 4. Combine and expanded uncetainty Sample Combine uncetainty Expanded uncetainty Este numbe (mg KOH/g) Acid numbe (mg KOH/g) Patchouli alcohol Este numbe (mg KOH/g) Acid numbe (mg KOH/g) Patchouli alcohol (%) (%) Pakem Ngaglik Sandaan ABLE 5. Este numbe, acid numbe and patchouli alcohol and its uncetainty Sample Este numbe (mg KOH/g) Acid numbe (mg KOH/g) Patchouli alcohol (%) Pakem Ngaglik Sandaan CONCLUSIONS Souce contibuto to measuement uncetainty of este numbe is a mass of the sample, a blank and sample titation volume, the mola mass of KOH, HCl nomality, and eplication. he esult of bottom-up appoach to detemine the measuement uncetainty of the acid numbe indicating the souce of uncetainty wee a mass of the sample, a sample titation volume, the mola mass of KOH, KOH nomality, and eplication. he highest contibuto to uncetainty measuement of este and acid numbes espectively wee nomality of HCl and eplication. Detemination of patchouli alcohol by Gas Chomatogaphy consides the souces of measuement uncetainty only fom epeatability. REFERENCES 1. Diektoat Jendeal Pekebunan, Statistik Pekebunan Indonesia: ee Cop Estate Statistics of Indonesia (Kementeian Petanian, Jakata, 013), pp. 40. N. S. Indeswai, Advanced Science Engineeing Infomation echnology 5, (015). 3. Allwa, L.N. Sai, K. Medekawati and D. Rubiyanto, Jounal of Applied Chemisty 8, pp (015). 4. S.A. Akie, A.H. Fans, A.C. Kumoo, Junal eknologi Kimia dan Industi, pp (013). 5. SNI : Minyak Nilam 6. EURACHEM/CIAC, Quantifying Uncetainty in Analytical Measuement (01). 7. Codex Alimintaius Commission, Guideline on Measuement Uncetainty (004). 8. D.B. Hibbet, Quality Assuance in he Analytical Chemisty Laboatoy, (Oxfod Univesity Pess, Oxfod, 007) 9. V.R. Meye, Jounal of Chomatogaphic Science 41, pp (003). 10. J.R. De Laete, J.K. Bohlke, P.De Beve, H. Hidaka, H.S. Peise, K.J.R. Rosma, and P.D.P. aylo, Pue and Applied Chemistyvol 75, pp (003)