Amendment to the Enforcement Ordinance of the Food Sanitation Law and the 
Standards and Specifications for Foods and Food Additives 
 
The government of Japan  will designate peracetic 
acid,1-hydroxyethylidene-1,1-diphosphonic ac id, and octanoic acid as food additives 
toenable the use of peracetic acid compos ition and establish specifications and 
standards for peracetic acid composition. 
 Summary 
Under Article 10 of the Food Sanitation Law (hereinafter referred to as the “Law”), 
food additives shall not be used or marketed  without authorization by the Minister of 
Health, Labour and Welfare (hereinafter referred to as “the Minister”). In addition, when 
specifications or standards are established for f ood additives based on Article 11 of the Law and 
stipulated in the Ministry of Health, Labour a nd Welfare Notification (Ministry of Health and 
Welfare Notification No. 370, 1959), those additiv es shall not be used or marketed unless they 
meet the standards or specifications. 
 
In response to a request from the Minister, the Committee on Food Additives of the 
Food Sanitation Council that is establishe d under the Pharmaceutical Affairs and Food 
Sanitation Council has discussed whether it is adequate to designate peracetic acid 
(PAA), 1-hydroxyethylidene-1,1-diphosphon ic acid(HEDP), and octanoic acid as 
additives for the purpose of using them as ingredients of peracetic acid composition. The conclusion of the committee is outlined below.  Outline of conclusion  
The Minister, based on Article 10 of the act, should designate PAA, HEDP, and 
octanoic acid as additives unlikely to harm  human health and establish specifications 
and standards for these additives and perace tic acid composition based on Article 11. 
    Attachment 
Peracetic Acid Composition, Peracetic Acid, 
1-Hydroxyethylidene-1,1-diphosphonic Acid, Octanoic Acid 
 
 Standard for use  
Peracetic acid composition:  Permitted only for the surface disinfection of edible meat 
(beef, pork, and poultry), fruits, and veget ables. The maximum use level is 2.0 g for 
poultry, 1.80 g for beef and pork, 0.080 g for fruits and ve getables, as the amount of 
peracetic acid in 1 kg of a dipping or spra y solution; and 0.136 g fo r poultry, 0.024 g for 
beef and pork, and 0.0048 g for fruits and vegetables, as the amount of 
1-hydroxyethylidene-1,1-diphosphonic acid in 1 kg of a spray or dipping solution. 
Fruits and vegetables include fresh vegetables and fruits that have been processed 
with simple processing, like pe eling, cutting, and freezing. 
Edible meat includes dressed, cut, sliced, and ground meat.  
 
Peracetic acid:  Permitted only as an in gredient of peraceti c acid composition. 
 
1-Hydroxyethylidene-1,1-diphosphonic acid:  Permitted only as an ingredient of 
peracetic acid composition. 
 Octanoic acid:  Permitted only for the purpose of flavoring foods or as an ingredient of peracetic acid composition.   Note: The use standard is established for hy drogen peroxide. Hydrogen peroxide shall 
be decomposed or removed before the completion of the final product. No use standard is established for acetic acid.   Standards for manufacturing  
Peracetic acid:  It shall be made of acetic  acid and hydrogen peroxide that meet the 
corresponding existing specification.   Peracetic acid composition:  It sha ll be a product manufactured by mixing 
1-hydroxyethylidene-1,1-diphosphonic acid wit h peracetic acid or with acetic acid and 
hydrogen peroxide, or a product manufacture d by adding octanoic  acid to the above mixture. Acetic acid, hydrogen peroxide, 1-hydroxyethylidene-1,1-diphosphonic acid, 
and octanoic acid that are used as ingredie nts of peracetic acid composition shall meet 
the existing specifications.   
 
Peracetic Acid Composition 
過酢酸製剤  
 
 Compositional specifications  
Substance name  Peracetic Acid Composition      
[CAS number]  [79-21 -0, Peracetic acid] 
Definition   Peracetic Acid Composition is an aqueous solution containing Peracetic 
Acid, “Acetic Acid,” “Hydrogen Peroxide,” and “1-Hydroxyethylidene-1,1-diphosphonic 
Acid” or an aqueous solution containing th ese four substances and “Octanoic Acid.” 
Peroctanoic acid may be produced from “Octanoic Acid” contained in “Peracetic Acid Composition.” 
Content    Peracetic Acid Composition contai ns 12–15% of peracetic acid, 30–50% of 
acetic acid, 4–12% of hydrogen pe roxide, and less than 1% of 
1-hydroxyethylidene-1,1-diphosphonic acid. In  addition, it can contain not more than 
10% of actanoic acid.  
Description  Peracetic Acid Composition is a co lorless, transparent liquid having a 
characteristic, pungent odor. 
Assay   
(1) Peracetic acid and acetic acid 
Sample Solution  Weigh accurately about 1 g of Pe racetic Acid Composition, and add 
water to make exactly 100 ml. 
Procedure  Pour 5 ml of ethanol, then 10 ml of  water into an octadecylsilanized silica 
gel minicolumn (500 mg), and di scard the effluent.  Pour 10 ml of the sample solution 
into the column, and collect th e effluent in a 100-ml beaker. Pour 10 ml of water into the 
column, add the effluent to the beaker, an d add about 50 ml of water to the beaker. 
Titrate the resulting solution with 0.1 mol/L sodium hydroxide using a potentiometer.  
Record the amounts (a ml and b ml) of the sodium hydroxide solution consumed at the first and second inflection poin ts to determine each content. 	Content	 ሺ%ሻ	of	peracetic	acid	ሺC ଶHସOଷሻൌሺୠିୟሻൈ଴.ଵൈ଻଺.଴ହ
୛ୣ୧୥୦୲	ሺ୥ሻ	୭୤	୲୦ୣ	ୱୟ୫୮୪ୣ	 
	Content	 ሺ%ሻ	of	acetic	acid	ሺC ଶHସOଶሻൌୟൈ଴.ଵൈ଺଴.଴ହ
୛ୣ୧୥୦୲	ሺ୥ሻ	୭୤	୲୦ୣ	ୱୟ୫୮୪ୣ	 
(2) Hydrogen peroxide 
Test Solution  Weigh accurately about 1 g of Peracetic Acid Composition, and  add 
water to make exactly 100 ml. Transfer 10 ml  of this solution, exactly measured, to a 
250-ml Erlenmeyer flask, and add 75 ml of sulf uric acid TS (0.5 mol/ L), cooled with ice.  
Procedure  Add 2 drops of ferroin TS to the test soluti on, and titrate with 0.1 mol/L 
cerium(IV) sulfate. The endpoint is when the color of the solution changes from orange 
to colorless through light red. De termine the content by the formula:   
 	Content	 ሺ%ሻ	of	hydrogen	peroxide	 ሺHଶOଶሻൌ 
		Consumption	 ሺmlሻ	of	0.1	mol/L		cerium ሺIVሻ	sulfateൈ0.1ൈ17.00
Weight	ሺgሻ	of	the	sample	 
(3) 1-Hydroxyethylidene-1,1-diphosphonic acid 
Test Solution   Weigh accurately about 0.2 g of Peracetic Acid Composition, and add 
water to make 50 ml. Transfer 3 ml of th is solution, exactly measured, to a 100-ml 
beaker, and add 50 ml of water. To this so lution, add 1 drop of phenolphthalein TS. 
When the solution turns light red, add sulfur ic acid TS (2.5 mol/L) until the light red 
color disappears. To this solution, add 2 ml of sulfuric acid TS (2.5 mol/L), and stir. Then 
add 0.4 g of ammonium peroxo disulfate, and stir. Heat the resulting solution with 
boiling chips on a hot plate for 90 minutes while replenishing the lost water, and then continue to heat until the volume of the soluti on is reduced to about  10 ml. After cooling, 
add 2 drops of phenolphthalein TS, then add 1 mol/L sodium hydroxide TS until the color of the solution becomes faint red. Transfer  this solution to a 50-ml volumetric flask, 
wash the boiling chips and the beaker a few times with a small amount of water, and 
add the washings to the flask. Make up with water to 50 mL and refer to the resulting 
solution as the sample solution. Measure exactly 10 ml of the sample solution, add 2.0 ml of antimony tartrate–molybdic acid TS, shake well, and allow to stand for 20 
m i n u t e s .                 
Reference Solution   Using 10 ml of water instead of the sample solution, proceed as 
directed for the sample solution, beginning  with “add 2.0 ml of antimony tartrate–
molybdic acid TS.”  
Standard Solutions  Dissolve 0.2195 g of potassium dihydrogen phosphate in water 
to make exactly 1000 ml. To 5 ml of this so lution, exactly measured, add water to make 
exactly 1000 ml. Use the resulting solution as the standard stock solution. Measure exactly 0 ml, 3 ml, 5 ml, 10 ml, 15 ml, and 20 ml of the standard stock solution in 
separate volumetric flasks, and add water to ea ch solution to make exactly 50 ml of each. 
Measure exactly 10 ml each of the resulting solutions, and proceed as directed for the sample solution, beginning with “add 2.0 ml of an timony tartrate–molybdic acid TS”.      
Procedure  Measure the absorbance of the test solution and the standard solutions at 
650 nm to prepare a calibrate curve. Determine the concentr ation of phosphorus in the 
test solution from the calibration curve and the absorbance of the test solution, and calculate the content of 1-hydroxyethylidene-1,1-diphosphonic acid (C
2H8O7P2) by the 
formula:  
 Content	ሺ%ሻof	ሺCଶH଼O଻Pଶ	ሻൌ	 	େ୭୬ୡୣ୬୲୰ୟ୲୧୭୬	ሺஜ୥	/୫୪ሻ	୭୤		୮୦୭ୱ୮୦୭୰୳ୱ	ൈ	ଶ଴଺.଴		
୛ୣ୧୥୦୲	ሺ୥ሻ	୭୤	୲୦ୣ	ୱୟ୫୮୪ୣ	ൈ	଺ଵ.ଽସ	ൈ	ଵଶ  
(4) Octanoic acid  
Test Solution  Weigh accurately about 0.7 g of Pe racetic Acid Composition, add a 1:1 
mixture of water and acetonitrile to make 50 ml. To 5 ml of this solution, exactly measured, add a 1:1 mixture of water and acetonitrile to make exactly 20 ml.  
Standard Solutions  Weigh accurately about 0.2 g of octanoic acid for assy, add a 1:1 
mixture of water and acetonitrile to make 100 ml. Use this solution as the standard 
stock solution. Measure exactly 0.5 ml, 1 ml , 2.5 ml, 5 ml, and 10 ml of the standard 
stock solution in separate volumetric fl asks, and add a 1:1 mixture of water and 
acetonitrile to each solution to make exactly 20 ml of each.   
Procedure  Analyze 20 μl portions of the test solution and the standard solutions by 
liquid chromatography using the operating condition given below. Measure the peak 
areas of octanoic acid in the standard solutions to prepare a calibration curve. Determine the concentration ( μg/ml) of octanoic acid in the test solution from the 
calibration curve and the peak area of actano ic acid in the test solution, and calculate 
the content of octanoic acid (C
8H16O2) by the formula:   
Content	ሺ%ሻ	of	octanoic	acid	ሺC ଼Hଵ଺Oଶሻൌେ୭୬ୡୣ୬୲୰ୟ୲୧୭୬	 ሺஜ୥	୫୪ሻ	୭୤	୭ୡ୲ୟ୬୭୧ୡ	ୟୡ୧ୢ	୧୬	୲୦ୣ	୲ୣୱ୲	ୱ୭୪୳୲୧୭୬	
୛ୣ୧୥୦୲	ሺ୥ሻ	୭୤	୲୦ୣ	ୱ୫୮୪ୣ	ൈ	ହ଴  
    Operating Conditions  
Detector: Ultraviolet absorption spectrophotometer (determination wavelength 210 
nm)  
Column: A stainless steel tube of 4.6 mm internal diameter and 25 cm length.  
Column packing material: 5- μm octadecylsilanized silica gel for liquid 
chromatography.  
Column temperature: 30 C.  
Mobile phase: A solution prepared by disso lving 0.12 g of acetic acid in 350 ml of water and adding 650 ml of acetonitrile.   
Flow rate: 1.0 ml/minute. 
  
1-Hydroxyethylidene-1,1-diphosphonic Acid 
1-ヒドロキシエチリデン -1,1-ジホスホン酸  
 
 
 
 Compositional specifications  
Substance name  1-Hydroxyethylidene-1,1-diphosphonic Acid 
Molecular formula  C2H8O7P2           
Molecular weight   206.03 
Chemical name [CAS number]  
 (1-Hydroxyethane-1,1-diyl)diphosphonic acid  [2809-21-4]  
Content  1-Hydroxyethylidene-1,1-diphosph onic Acid contains 58.0–62.0% of 
1-hydroxyethylidene-1,1-diphosphonic acid (C 2H8O7P2).  
Description  1-Hydroxyethylidene-1,1-diphosphonic Ac id is a colorless to light yellow, 
clear liquid.   
Purity  
(1) Specific gravity  1.430–1.471. 
(2) pH  Not more than 2.0 (1.0 g, water 100 ml). 
(3) Chlorides  Not more than 0.004% as Cl.                                
Weigh accurately about 25 g of 1-Hydro xyethylidene-1,1-diphosphonic Acid, add 
about 50 ml of water and 3 ml of nitric ac id. Titrate the resulting solution with 0.005 
mol/L silver nitrate using a potentiometer. Record the amount (a ml) of the silver nitrate solution consumed at the endpoint to determine the amount of chlorides by the following formula. If more than one inflecti on point exists, the endpoint is the last inflection point.    
 Amount	ሺ%ሻof	chlorides	 ሺClሻൌ	ୟ	ൈ଴.଴଴ହ	ൈଷ.ହସହ
୛ୣ୧୥୦୲		 ሺ୥ሻ	୭୤	୲୦ୣ	ୱୟ୫୮୪ୣ  
(4) Phosphorous acid  Not more than 4.0% as H 3PO 3. 
Weigh accurately about 1.5 g of 1-Hydroxye thylidene-1,1-diphosphonic Acid in an  
iodine flask, add 20 ml of water and 50 ml of phosphate buffer (pH 7.3), and adjust the 
pH of the mixture to 7.3 with sodium hydrox ide solution (1 in 2). Add 25 ml of 0.05 
mol/L iodine, exactly measured, immediately stopper tightly, and allow to stand for 15 
minutes at a dark place. Add 5 ml of acetic  acid, and titrate the excess iodine with 0.1 
mol/L sodium thiosulfate (indicator: 1–3 ml of starch TS). Add starch TS near the 
endpoint, when the color of solution change s to light yellow. The endpoint is when the 
blue color produced disappears. Separately, perform a blank test.  
Each ml of 0.05 mol/L iodine = 4.10 mg of H 3PO 3.   
(5) Lead  Not more than 5.0 g/g as Pb.  
Sample Solution    Weigh 0.80 g of 1-Hydroxyethy lidene-1,1-diphosphonic Acid in a 
platinum, quartz, or porcelain crucible or a quartz beaker. Add 1 ml of sulfuric acid, 
heat by gradually increasing the temperat ure until the sample is charred and white 
fumes of sulfuric acid are no longer evolve d. If necessary, add sulfuric acid again and 
heat until the sample is almost charred.  Cover the container loosely with a lid if 
necessary, heat in an electric furnace by  gradually increasing the temperature, and 
ignite at 450–600 C to incinerate the sample. When a charred mass remains, crush it 
with a glass rod if necessary, mo isten with 1 ml of diluted sulfuric acid (1 in 4) and 1 ml 
of nitric acid, heat until white fumes of sulfuric  acid are no longer evolved, and ignite in 
the electric furnace to completely incinerate  the sample. To the residue, add 10 ml of 
diluted hydrochloric acid (1 in 4), heat on a water bath, and evaporat e to dryness. To the 
residue, add 20 ml of diluted hydrochloric ac id (1 in 4), boil with a watch glass covering 
the container for 5 minutes, and cool.   
Test Solution  To the sample solution, add 10 ml of diammonium hydrogen citrate 
solution (1 in 2), and then add ammonium solution until the color of the solution 
changes from yellow to light ye llow-green using 1 ml of thymol blue TS as the indicator. 
Transfer this solution to a separating f unnel or centrifuge tube. Wash the container 
used for incineration with a small amount  of water or warm water, and add the 
washings to the funnel or tube, whichever ma y be appropriate. Add 5 ml of ammonium 
pyrrolidine dithiocarbamate solution (3 in 100), and allow to stand for 5 minutes. Add 
exactly 10 ml of butyl acetate, shake for 5 minutes, and allow to stand or centrifuge. 
Collect the butyl acetate layer.  Control solution  Measure exactly 1 ml of Lead Standard Stock Solution, and add 
water to make exactly 100 ml. Measure exactly 4 ml of Lead Standard Solution, and proceed as directed for the test solution.  
Procedure  Conduct tests for the test and co ntrol solutions by Method 1.  
(6) Iron  Not more than 10 g/g as Fe.  
Sample Solution Weigh accurately about 0.2 g of 
1-Hydroxyethylidene-1,1-diphosphonic Acid in  an appropriate container, and add 5 ml 
of nitric acid. Incinerate the sample in a microwave digestion  equipment at 230 C. After 
cooling, transfer the residue in a 50-ml vo lumetric flask, and make up with water to 
v o l u m e .             
Test Solution and Standard Solutions  To an appropriate amount of Iron Standard 
Solution, exactly measured, add diluted nitric acid (1 in 10) to prepare  standard stock 
solutions containing iron (Fe = 55.85) at th e concentrations of 10, 25, 50, 100, and 200 
ng per ml. Measure 10 ml each of the sample solution and the standard stock solutions 
in separate flasks, and add 40 l of the internal standard to each flask to prepare the 
test solution and the standard solutions, re spectively. Prepare the internal standard as 
follows: To 1.0 ml of Yttrium Standard Stock So lution, add diluted nitric acid (1 in 10) to 
make 100 ml. 
Procedure Proceed as directed in the Internal Standard Method under Inductively 
Coupled Plasma-Atomic Emission Spectrometry to measure emissions of the test solution and the standard solutions, and prepare a calibration curve. Determine the concentration (ng/ml) of iron in the test solution from the calibration curve, and 
calculate the iron amount ( g/g) by the formula: 
Amount	ሺμg/gሻ	of	iron	ሺFeሻ ൌ
୍୰୭୬	ୡ୭୬ୡୣ୬୲୰ୟ୲୧୭୬	ሺ୬୥/୫୪ሻ	୧୬	୲୦ୣ	୲ୣୱ୲	ୱ୭୪୳୲୧୭୬	
୛ୣ୧୥୦୲	ሺ୥ሻ	୭୤	୲୦ୣ	ୱୟ୫୮୪ୣ	ൈ	ଶ଴        
(7) Arsenic  Not more than 6.7  g/g as As 2O3 (0.30 g, Method 1, Apparatus B). 
Assay  Dissolve about 3 g of 1-Hydroxyethyliden e-1,1-diphosphonic Acid, accurately 
weighed, in 150 ml of water. Titrate this so lution with 1 mol/L sodium hydroxide using a 
potentiometer while stirring. The endpoint is the second inflection point. Record the 
consumption (a ml) of the sodium hydroxide at the endpoint, and calculate the content of 1-hydroxyethylidene-1,1-diphosphonic acid (C
2H8O7P2) by the formula: 
Content	ሺ%ሻ	of	CଶH଼O଻Pଶ	 
ൌ	a	ൈ206.0
Weight	ሺgሻof	the	sample	ൈ30			െamount	 ሺ%ሻof	phosphorous	acidൈ1.675  
  
Octanoic Acid 
Caprylic Acid 
オクタン酸   
 
 
 
 Compositional specifications  
Substance name  Octanoic Acid 
Molecular formula  C8H16O2           
Molecular weight  144.21 
Chemical name [CAS number]  Octanoic acid  [124-07-2]  
Content   Octanoic Acid contains not le ss than 95.0% of octanoic acid (C 8H16O2).  
Description  Octanoic Acid is a colorless, oil- like liquid. It has a faint odor.   
Identification  Determine the absorption spectrum of Octanoic Acid as directed in the 
Liquid Film Method under Infrared Spectrophotometry, and compare with the Reference Spectrum. Both spec tra exhibit absorptions having almost the same intensity 
at the same wavenumbers.  
Purity  
(1) Acid value  366–396. 
Weigh accurately about 0.3 of Octanoic Acid , and proceed as directed in Acid Value 
under the Flavoring Substances Tests.    
(2) Lead  Not more than 2.0 g/g as Pb.  
Test Solution    Weigh 2.0 g of Octanoic Acid in to a platinum, quartz, or porcelain 
crucible or a quartz beaker. Add 1 ml of sulf uric acid, and heat by gradually increasing 
the temperature until the sample is charred and white fumes of sulfuric acid are no 
longer evolved. If necessary, a dd sulfuric acid again, and he at until the sample is almost 
charred. Cover the container loosely with a l i d ,  h e a t  i t  i n  a n  electric furnace by 
gradually increasing the temp erature, and ignite at 450–600 C until the sample is 
incinerated. When a chatted mass remains, crush with a glass rod if necessary, moisten 
it with 1 ml of diluted sulfuric acid (1 in 4) and 1 ml of nitric acid, heat until white fumes are no longer evolved, an d ignite in the electric furn ace to completely incinerate 
the sample. To the residue, add 10 ml of diluted hydrochloric acid (1 in 4), heat on a water bath, and evaporate to dryness. To th e residue, add a small amount of diluted 
nitric acid (1 in 100), and dissolve it by warming. After cooling, make up with diluted 
nitric acid (1 in 100) to exactly 10 ml.  A he at-resistant glass beaker can be used when 
the incineration procedure is performed at a temperature not more than 500 C .       
Control Solution  Measure exactly 1 ml of Lead Standard Stock Solution, and add 
water to make exactly 100 ml. To 4 ml of th is solution, exactly measured, add diluted 
nitric acid (1 in 100) to make exactly 10 ml.  
Procedure  Proceed as directed in Method 1 under the Lead Limit Test.  
(3) D ecanoic acid  Not more than 3.0%. 
Test Solution  Use Octanoic Acid as the sample.  
Control Solution  Weigh 0.3 ml of decanoic acid and add 10 ml of Octanoic Acid  as 
the sample .   
Procedure Analyze the test solution and the control solution by gas chromatography 
using the operating conditions specified in As say to confirm decanoic acid of the test 
solution. Determine the sum (A T) of the peak areas of all the peaks that appear within 
the specified measurement time and the peak area (A S) of decanoic acid. Calculate the 
amount of decanoic acid by the formula.   
 Amount	ሺ%ሻ	of	decanoic	acid	 ൌ	୅౏
୅౐		ൈ100  
Water Content  Not more than 0.4% (5 g, Direct Titration).  
Residue on Ignition  Not more than 0.1% (10 g, 800 C, 15 minutes).  
Assay Proceed as directed under the Peak Area Percentage Method in the Gas 
Chromatographic Assay of Flavoring Agents under the Flavoring Substances Tests. Use 
operation conditions (1). Use a silicate gla ss capillary column (0. 25–0.53 mm in internal 
diameter and 30–60 m in length ) coated with a 0.25- to 1- μm thick layer of polyethylene 
glycol for gas chromatography.  The column temperature should be  raised from 150 to 
230C at a rate of 5 C/minute and then maintained at 230 C for 24 minutes.  
 
Regents and Solutions  Antimonyl Potassium Tartarate TS  Dissolve 1.37 g of 
bis[(+)-tartrato]diantimonate(III)dipotassium  trihydrate by adding 350 ml of water 
gradually, and make up with water to 500 ml.  
Antimony Tartrate–Molybdic Acid TS   To 50 ml of sulfuric acid TS (2.5 mol/L), add 5 ml 
of antimonyl potassium tartarate TS, 15 ml of a solution of hexaammonium heptamolybdate tetrahydrate (1 in 25), and 30  ml of ascorbic acid TS, and stir well. 
Prepare fresh before use.   
Ascorbic Acid TS   Dissolve 1.76 g of L-ascorbic acid in water to make 100 ml. 
Bis[(+)-tartrato]diantimonate(III)  Dipotassium Trihydrate   C
8H4K2O12Sb2•3H 2O  
[K 8533] 
Cerium(IV) Sulfate Tetrahydrate  Ce(SO 4)2•4H 2O  [K8976] 
Ferroin TS   To 0.70 g of iron(II) sulfate heptahydrate, add 70 ml of water and 1.78 g of 
1,10-phenanthroline chloride monohydrate to dissolve, and make up with water to 100 
ml.  
Decanoic Acid   C 10H20O2   A colorless to light yellow, clear liquid or white to faint 
yellow crystals or lumps.     
Content   Not less than 99.0%. 
Identification Proceed as directed in the Potassium Bromide Disc Method under 
Infrared Spectrophotometry. It exhi bits absorption bands at about 2676 cm–1, 1700 cm–1, 
1299 cm–1, 1268 cm–1, 1232 cm–1, 1200 cm–1, 1075 cm–1, 934 cm–1, 825 cm–1, and 686 cm–
1. 
Congealing point  29–33C. 
Assay   Weigh accurately about 0.05 g of Octanoic Acid for Assay, add 1 ml of 
N,O-bis(trimethylsilyl)trifluoroacetamide , stopper tightly, and mix well. Heat the 
mixture on a water bath for 30 minutes, and cool to room temperature. Analyze appropriate portions of the resulting so lution by gas chromatography using the 
operating conditions given below. Determine the area percentage of the main peak.   
Operating conditions  
Detector: Flame-ionization detector. Column: A silicate glass capillary column (0 .53 mm in internal diameter and 15 m in 
length) coated with a 1.5- μm thick layer of dimethylpolysiloxane for gas 
chromatography.   
Column temperature: Raise the temperature at a rate of 10 C/minutes from 60 C to 
280C.  Injection port temperature: 280 C. 
Detector temperature: 280 C. 
Injection method: Split (20:1). Set conditio ns so that any component of the sample 
does not exceed the column acceptable range.   
Carrier gas: Helium. 
Flow rate: Adjust so that the peaks of co mponents to be determ ined appear in 5–20 
minutes of injection.  
Octadecylsilanized Silica Gel Minicolumn (500 mg)   Use a polyethylene column (10–25 
mm in internal diameter) packed with 0.5 g of octadecylsilanized s ilica gel or a column 
comparable in separation property to the former one.  
Octanoic Acid for Assay   CH 3(CH 2)6COOH  A colorless to light yellow, clear liquid. 
  Content   Not less than 98.0%. 
Identification Proceed as directed in the Liqu id Film Method under Infrared 
Spectrophotometry. It exhibits  absorption bands at about 2930 cm–1, 2860 cm–1, 1710 
cm–1, 1460 cm–1, 1420 cm–1, 1280 cm–1, 1230 cm–1, 1200 cm–1, 1110 cm–1, 940 cm–1, and 
720 cm–1. 
Purity  (1) Congealing point   15–17C. 
(2) Refractive index  nୢଶ଴: 1.425–1.431. 
(3) Specific gravity 		dଶ଴ଶ଴: 0.909–0.915. 
Assay   Weigh accurately about 0.05 g of Octanoic Acid for Assay, add 1 ml of 
N,O-bis(trimethylsilyl)trifluoroacetamide , stopper tightly, and mix well. Heat the 
mixture on a water bath for 30 minutes, and a llow to cool. Analyze appropriate portions 
of the resulting solution by gas chromatogr aphy using the operating conditions given 
below. Determine the area percentage of the main peak.   
Operating conditions  
Detector: Flame-ionization detector. Column: A silicate glass capillary (0.53 mm in  internal diameter and 15 m in length) 
coated with a 1.5- μm thick layer of dimethylpolysiloxane for gas 
chromatography.   
Column temperature: Raise the temperature at a rate of 10 C/minutes from 50 C to 
280C, and then maintain at 280 C for 2 minutes.  
Injection port temperature: 280 C. 
Detector temperature: 280 C. 
Injection method: Split (20:1). Set conditio ns so that any component of the sample 
does not exceed the column acceptable range.   
Carrier gas: Helium. Flow rate: Adjust so that the peaks of co mponents to be determined appear in 5–20 
minutes of injection. 
1,10-Phenanthroline Chloride  Monohydrate  C12H9ClN 2･H2O [K8202] 
Phosphate Buffer (pH 7.3)   Dissolve 138 g of monosodium phosphate in 800 ml of water. 
Adjust the pH of this solution to 7.3 with sodium hydroxide solution (1 in 2), and add 
water to make 1000 ml. 
Sulfuric Acid TS (0.5 mol/L)    Add 14 ml of sulfuric acid gradually to 350 ml of water. 
After cooling, make up with water to 500 ml.  
Sulfuric Acid TS (2.5 mol/L)   Add 70 ml of sulfuric acid gradually to 350 ml of water. 
After cooling, make up with water to 500 ml.  Volumetric Solution 
0.1 mol/L Cerium(IV) Sulfate  This solution contains 40.43 g of cerium(IV) sulfate 
tetrahydrate (Ce(SO 4)2•4H 2O, molecular weight: 404.30) per 1000 ml. 
   To about 40.4 g of cerium(IV) sulfate te trahydrate, add 50 ml of sulfuric acid, and 
mix. To the mixture, add 900 ml of water in 20-ml portions while stirring, being careful 
about heat generation. Allow to  stand for 24 hours, filter the solution through a glass 
filter, and add water to make 1000 ml. 
Standardization  Measure exactly 25 ml of 0.1 mol/L cerium(IV) sulfate, add 30 ml 
of diluted sulfuric acid (1 in 6), and ti trate with 0.1 mol/L ammonium ferrous sulfate 
(indicator: about 0.2 ml of ferroin TS). The endpoint is when the color of the solution changes blue-green to yellow- red. Calculate the normality factor by the formula: 
f = f
1 ×V/25 
f :  factor of 0.1 mol/L cerium(IV) sulfate  f
1 :  factor of 0.1 mol/L ammonium ferrous sulfate  
V :  volume (ml) of 0.1 mol/L am monium ferrous sulfate consumed 
0.005mol/L Silver Nitrate  This solution contains 0.8493 g of silver nitrate (AgNO 3, 
molecular weight:169.87) per 1,000 ml. Prepare by diluting 0.1 mol/L silver nitrate with 
water to 20 times its original volume.   Standard Solutions 
Yttrium Standard Stock Solution  Each ml of this solution contains 1 mg of yttrium 
(Y). Use a product prepared for inductively coupled plasma-atomic emission spectrometry.
  
 Infrared Reference Spectrum   Octanoic Acid