Measuring Hydrocarbon Oil Index according to ISO 9377-2 (DIN H53)

Introduction

The Hydrocarbon Oil Index (HOI) is defined

as the total amount of compounds which

can be extracted from the sample (potable

water, surface water and waste water)

with a non-polar solvent having a boiling

point between 39C and 69C (replacing

the use of halogenated solvents). In

addition, the compounds must not absorb on

Florisil and must elute between n-decane

(C10H24) and n-tetracontane (C40H82)

when analysed by GC using an apolar

analytical column. Restrictions on the use of

halogenated hydrocarbons as solvents for

analytical applications combined with the

increasing cost of and reduced availability of

technical grade halogenated solvents as well

as documented environmental

Abstract

Agilent Technologies developed this ana-

lytical method to comply with ISO 9377-2

and DIN H53 Standards. The method

employs a simple instrument configuration

consisting of a Gas Chromatograph (GC)

equipped with a Split/Splitless (S/SL) inlet

and Flame Ionisation Detector (FID), making

the method both easy to implement and

robust to operate. The combination of an

Agilent GC system (see configuration

above), selected capillary GC column,

proprietary injection port liner, appropriate

chemical standards as well as method

installation and support by an Agilent

Applications Specialist, provide a complete

solution for the measurement of the

Hydrocarbon Oil Index.

Gas ChromatographyBernhard Wst

Environmental Application

considerations resulted in the change to a

non-polar solvent for HOI determinations.

This analytical method complies with the

ISO Standard 9377-2 for the determination

of the Hydrocarbon Oil Index by Gas

Chromatography. The method is suitable for

HOI determinations in concentrations above

0.1 mg/L in drinking waters, surface waters,

waste waters and waters from sewage

treatment plants.

ExperimentalThe Agilent 6890 and Agilent 6850 GasChromatographs are well suited to the HOIapplication. Both instruments use the sameSplit/Splitless inlet system and identicalFlame Ionisation Detector. Discriminationeffects on higher boiling compounds are themost critical aspect of the analysis and areprevented by the use of a special injectionport liner which, in combination with theAgilent S/SL inlet system, produces robustand reliable data. Additional benefits suchas reduced maintenance time and fasteranalytical cycle times are also available byusing a S/SL inlet as compared to a Cool-on-Column inlet.The Agilent GC ChemStation standardsoftware is able to subtract backgroundsignals to produce a chromatogram withany column bleed removed. In addition, boththe Agilent 6890 and 6850 are able to savecolumn compensation signals in memoryand subsequently subtract the columnbackground from the sample data andprovide a background-subtracted signal tothe ChemStation or data integrationsystem. Standard ChemStation softwaretools are used to control the GC andperform the data analysis required of thesample data. A custom report template isincluded with the HOI method andgenerates a report conforming to the ISOStandard (see figure 3).

Publication number 5988-0621EN Agilent Technologies Page 2

min5 10 15 20 25 30

pA

10

20

30

40

50

60

70

80

90

FID1 A, (HYC2509\007F0702.D)

2.0

45 2

.158

2.2

50 2

.513

2.6

01 2

.783

3.0

11 3

.128 3

.377

3.4

94 3.

647

4.1

03 4

.207

13.

331

22.

535

22.

641

Instrument Parameters

Oven temperature Isothermal 35C (1.5 min), ramp 5C/min to 60C hold 0 min, profile ramp 15C/min to 350C hold 5 min.Inlet (S/SL) 375C Splitless ModeDetector (FID) 375CAnalytical Column Agilent Part Number 19095Z-221E (HP1, 15m x 0.53mm x 0,15 m) Inlet Liner Agilent Part Number 5183-4647Carrier Gas HeliumCarrier Gas 7.4 ml/min Constant Flow ModeFlow RateInjection Mode Automated (Agilent 7683) Fast InjectionInjection Volume 1.0 l

Figure 2: 0.6 mg/ml Oil Standard

Figure 1: Oil Standards Calibration Curve

Calibration Curve

Amount[mg/ml]0 0.5 1 1.5

Area

0

5000

10000

15000

20000

25000

30000

35000

40000

12

3

4

5

6

7

Hydrocarbon Index, FID1 A

Correlation: 0.99918

Rel. Res%(7): -4.0289e-1

Area = 20647.3902*Amt -375.37592Hydrocarbon Index, FID1 AArea = 20647.3902*Amt-375.37592

Correlation: 0.99918

Amount [mq/m]

Area Rel. Res%(7):-4.0289e-1

Discrimination Test:25 sequential injections of a standardcontaining tetracontane C-40 and decane C-10 were run to test for discriminationeffects within the analytical system. Thedata obtained is presented in Figure 3 anddemonstrates the robustness of the methodand that the analytical system clearlypasses the discrimination test specified inthe ISO Standard.

Results and DicussionThe Agilent 6890 and 6850 GasChromatographs equipped with aSplit/Splitless inlet and Flame IonisationDetector can be used for Hydrocarbon OilIndex determinations in accordance with ISO9377-2 (DIN H53) standard. In addition, theanalytical system is easy to operate andrequires minimal maintenance. Together, theAgilent GC, analytical capillary column,special inlet liner, custom report template,selected chemical standards and Agilentapplications expertise provide a completeanalytical solution for Hydrocarbon Oil Indexdeterminations.

Publication number 5988-0621EN Agilent Technologies Page 3

Figure 3: Discrimination Test

Figure 4: Report Printout

50.0

60.0

70.0

80.0

90.0

100.0

110.0

120.0

130.0

140.0

150.0

1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0 13.0 14.0 15.0 16.0 17.0 18.0 19.0 20.0 21.0 22.0 23.0 24.0

A mount / Run No. [Decane C10] A mount / Run No. [Tetracontane C40] Amount ( Mean ) A mount ( Mean )

min5 10 15 20 2530

pA

10

20

30

40

50

60

70

80

FID1 A, (HYC2509\008F0802.D)

2.0

44 2.1

56 2

.248

2.5

12 2

.599

2.7

81 3

.009

3.1

27 3

.254

3.3

78 3

.492

3.6

45 4

.101

4.2

07

13.

332

22.

533

============================================================================

Hydrocarbon Index Report============================================================================

Calib. Data Modified : Fri, 29. Sep. 2000,08:25:56 amMultiplier : 1.000000

Hydrocarbon Index 1.052 mg/mlLow Boilers 9.061 mg/lHigh Boilers not detectable mg/l

============================================================================

Detailed Report============================================================================

Name StartTime EndTime Ret Time Total Area Res.F Amount----------------------------------------------------------------------------

Low Boilers 2.00 4.00 - 239.48 0.03784 9.06Decane C10 - - 4.21 213.73 0.03784 8.09Hydrocarbon Index 4.31 22.37 13.33 15408.08 0.00006 1.05Tetracontane C40 - - 22.53 205.67 0.03247 7.94High Boilers - - - - - n.d.============================================================================

Data file : C:\HPCHEM\1\DATA\HYC2509\008F0802.DSample Name : 1000 mg/l 1===================================================================

Injection Date : 9/26/2000 3:23:50 AM Seq Line : 8Sample Name : 1.0 mg/ml Vial No. : 8Acq Operator : berwuest Inj. No. : 2

Inj. Vol. : -Acq.Method : HYCA04.MAnalysis Method : C:\HPCHEM\1\METHODS\ISO93774.MLast Changed : Fri, 29. Sep. 2000, 10:04:10 am

Analysis of Hydrocarbon Index according to Iso 9377-4 andDIN H53

Copyright 2000 Agilent TechnologiesAll Rights Reserved.

Reproduction, adaptation or translationwithout prior written permission is prohibited, except as allowed under thecopyright laws.

Agilent Technologies shall not be liablefor errors contained herein or forincidental or consequential damages inconnection with the furnishing,performance, or use of this material.

Information, descriptions andspecifications in this publication aresubject to change without notice.

Publication Number 5988-0621EN

Bernhard Wst is an application chemistbased at Agilent Technologies GmbHHewlett Packard Str. 876337 WaldbronnGermany

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