SELECTED ARTICLE. Soil Analysis Using Portable VOC Analyzer, MS-200. Yoshihiko ARITA. Land Consultant/ Geological Survey Company.

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1 SELECTED ARTICLE Soil Analysis Using Portable VOC Analyzer, MS-200 Yoshihiko ARITA Land Consultant/ Geological Survey Company Manufacturer of Water Plant/Analytical Service Company Discovery of Contaminated Soil Assessment of Analysis Soil/Groundwater Purification Treatment Monitoring Site Put To New Use High-speed Analysis Reliability Daltons Qualitative Analysis by Mass Spectrometry Quantitative Analysis by Multi-Variate Analysis Abstract In recent years, after the revelation of trichloroethylene-contaminated groundwater and the unlawful dumping of toxic waste, analytical services, construction companies, and other related businesses are taking active steps toward cleaning polluted and contaminated air, soil, and water and the rehabilitation of weakened environmental functions. Horiba has developed the MS- 200 fast VOCs (Volatile Organic Compounds) analyzer based on the time of flight mass spectrometry. With features of high speed, sensitivity, and portability, the MS-200 can measure concentrates of VOCs in a wide range of processes from pollution surveys to purification. In this paper, I will report some application data from, and discuss future assignments on, soil analysis and the MS-200.

2 SELECTED ARTICLE Soil Analysis Using Portable VOC Analyzer, MS-200 Introduction Soil, along with air and water, is an important part of our natural environment. However, when we look back at past cases of environmental pollution in Japan it has usually been air and water that have received the most attention. Soil pollution with the industrial development, a term which also refers to contamination of groundwater, has become a source of concern more recently, starting in the 970s when contaminants in soil began increasingly to be detected at industrial sites and places where factories had once stood. However, the seriousness of soil pollution was still not recognized fully by Japanese society as a whole. In some other advanced industrialized nations, the US in particular, the importance of having clean soil came to be understood more rapidly. The US instituted its socalled Superfund Act back in 980 and since then there has been a more comprehensive approach to tackling soil and groundwater pollution. In Japan, too, the significance of the role soil plays in the natural environment has finally been recognized, and the public is rapidly becoming more aware of the contaminated soil problem. In 99 the government introduced its Environmental Quality Standards for Soil Pollution, followed by Environmental Quality Standards for Groundwater Pollution in 997. In the same year, the government passed revisions to its Waste Disposal and Public Cleaning Law, which for the first time outlined the legal responsibilities of producers of industrial waste. So far, these measures taken by governments focus mainly on preventing pollution from occurring in the first place, but it is also urgent that we work to clean up existing contaminated soil and groundwater, to repair the damage that has already been done. Horiba's MS-200 Portable VOCs Analyzer developed based on a conventional time of flight mass spectrometer model by Horiba and Kore technology (UK), can measure amounts of eleven different Volatile Organic Compounds (VOCs) contained in soil and groundwater with high-speed. and high-sensitivity. From the standpoint of measuring, it has an important contribution to make to the process of clearing up soil/groundwater pollution, from preliminary site survey work through to the task of treatment and purification. For further information on the scientific principles of how the MS-200 works, and details relating to the design and configuration of its hardware, please refer to a previous edition ) of this journal. (Readout No. 7, pp.57-60) Note ) : Stipulated under US Federal Law. Superfund is the commonly used term to refer to the Comprehensive Environmental Response, Compensation and Liability Act of 980 (CERCLA). This legislation puts the onus on those who cause pollution to remedy the situation and to shoulder the financial burden of doing so. The reason for the Super Fund nametag comes from the fact that the law included provision for a large fund (approx. $8.5 billion) to be set up for pollution cleanup work. 2 The MS Its Sensitivity and What It Measures The Environmental Quality Standards Relating To Soil Pollution outline eleven harmful substances, or VOCs. All, with the exception of Benzene, are chlorides that are suspected of being able to accumulate in the human body and of having carcinogenic properties. Table shows the environmental standards for each of the substances, along with the minimum detection limit of the MS-200. The environmental standards refer to concentrations of the substances found in a test solution made up of a mixture of 20g of soil sample and 200ml of distilled water. The test solution is put in a 500ml vial and the concentration of vaporized gas in the 300ml headspace is worked out theoretically. Comparing the MS-200 with the environmental standard methodology data side by side, we can see that the MS-200 is approximately from 0 to,000 times more sensitive for the vaporized gas of the sample concentration. MS-200 Vaporized gas Environmental Soil VOCs MDL[3 ] in head space Standard (ppb) (ppb) (mg/l) Dichloromethane DCM CH 2 Cl Tetrachloromethane TCM CCl ,2-Dichloroethane,2-DCA C 2 H 4 Cl ,-Dichloroethylene,-DCE C 2 H 2 Cl cis-,2 cis-,2 C 2 H 2 Cl Dichloroethylene -DCE,,-Tticloroethane MC C 2 H 3 Cl ,,2-Tricloroethane,,2-TCA C 2 H 3 Cl Trichloroethylene TCE C 2 HCl Tetrachloroethylene PCE C 2 Cl ,3-Dichloropropene,3-DCP C 3 H 4 Cl Benzene C 6 H Table VOCs in the Environmental Standards that relate to Soil Pollution and MS-200 Sensitivity 2 No.22 March 200

3 3 Needs Relating to Measuring Soil/Groundwater Pollution, and the Method Of Analysis The actual conditions of soil/groundwater contamination vary greatly from site to site. Therefore, it is necessary to base any cleanup plans on an accurate survey of the extent and severity of the pollution, and also to take into consideration the geology of the site. Fig. is a flow diagram that shows the general process from initial diagnosis through to site cleanup. For the preliminary soil gas survey, conducted to grasp the extent of pollution on the surface, several different methods of analysis are applicable. The sensitivity of each method is shown in Table 2. The sampling density denotes the spacing intervals at which readings must be taken in order to build up a clear picture of pollution at the site. The more sensitive the method of analysis, the more spread out these intervals can be. The MS-200 corresponds to a mid to highly sensitive method, and can be taken to the survey site along with a portable Gas Chromatographic Analyzer using Photoionization Detector (GC-PID). Diagnosis No Action Necessary Treatment Survey of Materials (Investigate how site was previously used/conduct interviews) Possibility of Soil Contamination? Yes/No Soil Gas Survey Boring Survey Groundwater Survey Less Within Environmental Standards? More (To find the extent of contaminated area) (To find depth of contamination in areas where high concentrations of pollutants occur) (To find the ground water contamination nearby wells ) Environmental Quality Standards for Soil Pollution (99) (Environment Agency notice 99) Environmental Quality Standards for Groundwater (997) (Environment Agency notice 997) Survey Analysis Detection Sampling Method Method Limit Density Low Sensitivity Detection Tube 000ppb 5m Mid Sensitivity GC-PID 50ppb 20m MS-200 0ppb High Sensitivity Activated Carbon 0.ppb 50m Absorption GC-MS 4 Principle of operation Table 2 Methods of Soil Gas Analysis MS-200 Specifications The main specifications of the MS-200 are shown in Table 3. Because the MS-200 does not feature gas chromatography, it uses multi-variate analysis software for calculating concentrations of the substances it detects. In this way it can give quantitative results, even from mixed samples. Also, measuring time is approximately ten seconds, regardless of the number of substances involved. Membrane Inlet - Time of Flight Mass Spectrometry Ionization method Electron Impact (70eV) Mass range -500u Mass resolution 250 and above (at 00u) Subjects Max. of 20 different substances can be measured simultaneously Display outputs Mass spectrograph, tabulated results of calculated concentrations, trend graph of concentrations Concentration By Multi-Variate Analysis calculations Operating 0-40 C temperature range Operating 85 %, or less humidity range Power supply AC 00V (using AC adapter)/ DC 2V internal battery (battery life approx. 2.5 hours when taking measurements) External dimensions mm Weight Approx. 20kg (including battery) Table 3 Main Specifications of the MS-200 Soil Purification/ Rehabilitation Monitoring Groundwater Purification/ Rehabilitation (By pumping, vacuum extraction, bioremediation, etc.) Follow-up Confirm Results Create Record (By monitoring, sample analysis) (Present copy to government authorities) Fig. The Diagnosis-Cleanup Process for Contaminated Soil/Groundwater 3

4 SELECTED ARTICLE Soil Analysis Using Portable VOC Analyzer, MS Actual Examples 5. Measuring soil samples using the MS-200 and GC-PID The MS-200 and GC-PID were used to analyze five different real soil samples. The samples were prepared, as outlined above, as test solutions, and Table 4 shows the results obtained from readings of the headspace gas. Sample cis-,2-dce(mg/l) TCE(mg/L) PCE(mg/L) No No No No > No > Table 4 Comparison of Results of Real Soil Samples Analyzed by MS-200 (top) and GC-PID (bottom) Three substances - cis-,2 Dichloroethylene (cis-,2 DCE), Tetrachloroethylene (TCE) and Perchloroethylene (PCE) - were investigated, and in Table 4 the upper readings are those obtained from the MS-200 and the lower readings from the GC-PID. With the exception of Sample 3, both sets of results correlate nicely. In the case of Sample 3 it can be seen that the results from the GC- PID were several orders of magnitude higher than those from the MS-200, but after analysis with the MS-200's mass spectrometer it was shown that the GC-PID's readings had suffered interference from other substances. Fig.2 shows the spectrum of readings of Sample 3 and the TCE/PCE standard samples. The MS-200 is capable of performing qualitative analysis by means of mass spectrometry, in addition to carrying out multi-variate quantitative calculations. Table 5 compares the specs of the MS-200 with those of the GC-PID. Ion counts.6e+05.4e+05.2e+05.0e E E E+04 TCE peaks #30,32,34 Sample No.3 Standard PCE peaks #64,66,68 MS-200 GC-PID Speed Warm-up time 30 minutes Approx. 90 minutes Operating time 5 minutes per minutes sample per sample Sensitivity Benzene 4.5ppb (3σ) 9ppb (3σ) Table 5 Perchloroethylene 0.3ppb (3σ) 3ppb (3σ) Comparison of MS-200 and GC-PID Specifications 5.2 Measuring wastewater samples using the MS- 200 and GC-FID Monitoring concentrations of contaminants discharged from factories and other industrial sites is extremely important in order to prevent soil/groundwater pollution. The MS-200 and a laboratory-use GC-FID were used to measure benzene concentrations in samples of wastewater collected from the discharge of real factories. Fig.3 shows the MS-200 readings on the x-axis and the GC-FID readings on the y-axis. The Fig. shows a very good correlation between the results of the two instruments. Furthermore, the time taken per investigation was only approximately five minutes with the MS-200, which took measurements from the sample water headspace gas. The GC-FID took much longer, requiring around thirty minutes to prepare the sample by extracting benzene with an organic solvent, followed by another forty minutes to take the actual GC readings. Fig.3 GC-FID (ppm) R 2 = MS-200 (ppm) Analysis Result of Benzene Concentration in the Factory-Discharged Water by MS-200 and GC-FID 2.0E Mass number Fig.2 Results of Analysis of TCE/PCE Standard Samples and Sample No.3 4 No.22 March 200

5 6 New Developments 7 Summary Fig.4 shows how concentrations of so-called sick.building substances 2) - Toluene, o-, m-, p-xylene and p-dichlorobenzene - restrictions on the usage of which are currently being considered, were found to change when monitored at 5-minute intervals. Immediately after the room's ventilation fan was turned on, the MS-200 detected that the concentrations of the substances in the room began to gradually decrease. The MS-200 was able to take almost continuous readings, which suggests that it could be used as a monitoring device when soil and groundwater cleanup work is undertaken. For reference, Table 6 shows the tentative standards which are related to VOCs in sick building syndrome along with the minimum, but this still means the same as the original. detection limit of the MS-200. Note 2) : Sick building substances These substances can cause any of the symptoms common in cases of sick building syndrome. VOCs, in particular, are major suspects in these cases. Main peak ions of Toluene.5E+05.0E E+04 Ventilator ON Toluene o,m,p-xylene p-dichlorobenzene.5e+04.0e E+03 0:07 0:36 :05 :34 2:02 2:3 3:00 3:29 Real time Fig.4 Main peak ions of Xylene and p-dichlorobenzene Results of Continuous Indoor Monitoring of Toluene, o-, m-, p-xylene and p-dichlorobenzene Concentrations Sick-house VOCs MS-200 Tentative MDL[3 ](ppb) standard(ppb) Toluene C 7 H 8 70 o,m,p-xylene C 8 H p-dichlorobenzene C 6 H 4 Cl 2 40 Ethylbenzene C 8 H 0 3 Table 6 Tentative Standards of Sick Building VOCs and Minimum Detection Limit of MS-200 It has been described how the MS-200 can be used for soil gas analysis, with results backed up by data from GC analysis. The most striking feature of the MS-200 is undoubtedly the speed with which it can analyze samples, but its sensitivity and accuracy should also be noted. However, the actual conditions of soil and groundwater contamination differ greatly from site to site, and it is not unusual for this pollution to include foreign matter derived from fuel oil and machine oil. From now on, more investigations will have to be carried out by conducting surveys at other sites to collect data on how these impurities interfere with the analysis in order to work out the best conditions for the analyzing process. Also, in order to use the MS-200 as a method of highsensitivity analysis, more verification of data on lowconcentration samples needs to be carried out using the both the GC-MS methods. Finally, I would like to express my gratitude to KOKUSAI KOGYO Co., Ltd. and LCA, Co., Ltd. for supplying me with data on the results of soil samples. References ) "Environmental Quality Standards and Evaluation Standards Relevant to Soil and Groundwater. Administrative guidance" published by Ministry of Environment. 2) "Present Environmental State and Countermeasure of Soil and Ground Water" published by Japan Society of Water Environment 3) Hirano Takashi & Aritoshi Yoneda, "Portable VOCs Analyzer, MS-200", Readout Horiba Technical Reports, No. 7, (999) Yoshihiko ARITA Environmental & Process Instruments R&D Dept. Horiba, Ltd. 5