Spark Source Mass Spectrometry Research Articles

Structural and dielectric properties of boron-doped and un-doped mullite thin films

A sol–gel technique being simple, low cost and application oriented has been used to synthesize doped and un-doped mullite sols. These films have been spin-coated onto copper substrates. Effect of boron doping on the transformation kinetics of mullite was studied by preparing two sols with ratio Al/Si/B = 3/1/0 and Al/Si/B = 3/1/0.5. Surface morphology of thermally stable films showed uniformity in doped and un-doped samples. X-ray diffractometer results revealed orthorhombic mullite formation from both sols at a temperature of 500 °C for un-doped and at 350 °C for doped mullite films. Small crystallite size ~11 nm and low dielectric value ~5.84 (at 3 MHz) were observed in boron-doped films. Un-doped mullite films also showed relatively low dielectric constant, ~6.36, as compared to the previously reported values. The stoichiometry of films was confirmed by EDX and spark source mass spectrometry.

Development of characterization procedure of particulate matter pollution collected in immediate vicinity of urban residents

Advantage of using individual dust meters over traditional stationary particulate matter (PM) air pollution monitoring is evaluated. Data of air pollution levels obtained from the three municipal stationary monitoring stations were compared with data of individual dust meters SidePak AM 510. Results of a few control series of this comparison have indicated important differences between the mentioned two types of synchronised measurements. Taking into account that vast majority of time people spend indoors, one may expect that individual samplers better characterise exposition of any human being on the PM urban pollution. As a result, a new sampling procedure is proposed. It allows the collection of particulate matter in the immediate vicinity of human being: As collectors of the PM, we propose mobile phones, accompanying people whatever is their everyday activity. Namely, dust deposited in the inner parts of the used mobile phones is extracted and analysed. The procedure consists of bulk analysis performed with spark source mass spectrometry (SSMS) and depth profile analysis made by secondary ion mass spectrometry (SIMS). Exemplary results are presented of the particulate material deposited on high purity indium foils. Ion erosion is done with 5 keV Ar+, 150‐µm diameter ion beam scanned over 2 × 2.5 mm area. The analyser is equipped with Physical Electronics ion gun and QMA‐410 Balzers quadrupole mass spectrometer. Copyright © 2014 John Wiley & Sons, Ltd.

Virtual Leaps in Distance Education: A Conversation with Dr. Naveed A. Malik, Founding Rector of the Virtual University of Pakistan

Executive SummaryBesides being an honest, knowledgeable, humble, and respected man, Dr. Naveed A. Malik is the Founder-Rector of the Virtual University of Pakistan. In his position as the Rector, Dr. Malik is the Chief Executive and Academic Officer of the University and his responsibility is ensure that the provisions of the Virtual University Ordinance, the Statutes, the Regulations and Rules are faithfully observed in order promote teaching, research, administration, general efficiency and good order of the University.Dr. Malik obtained his Master's degree in Physics from the University of Punjab, Pakistan and later the Doctor of Science degree from M.I.T. in the field of Electrical Engineering and Computer Science specializing in Digital Signal Processing. As a staff member at the University of the Punjab, Dr. Malik established the Spark Source Mass Spectroscopy laboratory and later, became the founder chairman of the Department of Computer Science. He was the principal architect and developer of the Punjab University's computerized examination system and was also responsible for the design and implementation of the University's fiber-optic campus-area network that was commissioned in 2000. He has been associated with the Virtual University project from its inception date. He has lectured extensively, has been an active systems and software development consultant and has published several papers on various technical subjects. Dr. Malik is currently coordinating an IDRC funded multi-country research effort in distance learning technologies. He is a life member of the Pakistan Institute of Physics and was awarded the Sitara-e-Imtiaz in 2008 for services education.Virtual University (lrU). The Virtual University of Pakistan, which is one of the first universities around the world that is based on modern communication technologies,1 was established by the Pakistani government as a public sector, not-for-profit institution with a mission to provide extremely affordable world class education aspiring students all over the As part of its education process, VUP uses free-to-air satellite television broadcasts and the Internet, which allows students follow its rigorous course and programs regardless of their ability attend face-to-face sessions or their physical locations. This process alleviates the lack of capacity in the existing universities while simultaneously tackling the shortage of qualified professors in each field of study. By identifying the best professors within the country or outside of the country in various subjects, regardless of their institutional affiliations, and requesting them develop and deliver hand-crafted courses, VUP aims at providing the very best courses students around the country. VUP's degrees are recognized and accepted all over Pakistan as well as overseas. VUP opened its virtual doors in 2002 and in a short span of time has reached throughout the country serving over 100,000 students. Furthermore, VUP is associated with more than a hundred institutions providing infrastructure support students across the country at a fraction of the cost of traditional educational organizations.VUP delivers education through a thoughtful combination of broadcast television and the Internet. VUP2 courses are designed and delivered by knowledgeable and published experts in the field. For each course's topics, professionally developed lectures are recorded at the school's studio environment and they are accompanied by relevant slides, video clips and other materials for broadcast students. Besides being broadcasted over the television networks, course lectures are also made available in the form of multimedia CDs which are sent registered students. These course lectures are also available as streaming media from the Virtual University's servers their students.The multiple formats allow flexibility for students who may view the lectures at a time of their choosing. …

A theoretical study of SnF2+, SnCl2+, and SnO2+ and their experimental search

We present a detailed theoretical study of the stability of the gas-phase diatomic dications SnF(2+), SnCl(2+), and SnO(2+) using ab initio computer calculations. The ground states of SnF(2+), SnCl(2+), and SnO(2+) are thermodynamically stable, respectively, with dissociation energies of 0.45, 0.30, and 0.42 eV. Whereas SnF(2+) dissociates into Sn(2+) + F, the long range behaviour of the potential energy curves of SnCl(2+) and SnO(2+) is repulsive and wide barrier heights due to avoided crossing act as a kind of effective dissociation energy. Their equilibrium internuclear distances are 4.855, 5.201, and 4.852 a(0), respectively. The double ionisation energies (T(e)) to form SnF(2+), SnCl(2+), and SnO(2+) from their respective neutral parents are 25.87, 23.71, and 25.97 eV. We combine our theoretical work with the experimental results of a search for these doubly positively charged diatomic molecules in the gas phase. SnO(2+) and SnF(2+) have been observed for prolonged oxygen ((16)O(-)) ion beam sputtering of a tin metal foil and of tin (II) fluoride (SnF(2)) powder, respectively, for ion flight times of about 10(-5) s through a magnetic-sector mass spectrometer. In addition, SnCl(2+) has been detected for (16)O(-) ion surface bombardment of stannous (tin (II)) chloride (SnCl(2)) powder. To our knowledge, SnF(2+) is a novel gas-phase molecule, whereas SnCl(2+) had been detected previously by electron-impact ionization mass spectrometry, and SnO(2+) had been observed before by spark source mass spectrometry as well as by atom probe mass spectrometry. We are not aware of any previous theoretical studies of these molecular systems.

Preparation of high-purity single-crystal W and W〈Nb〉 via chemical vapor transport

High-purity single-crystal W and W〈Nb〉 have been prepared using chemical vapor transport. The impurity composition of the materials has been determined using spark source mass spectrometry and high-temperature vacuum extraction. The radial Nb profile in the alloy has been investigated by electron microscopy.

SIMS depth profile analysis of particles collected in an urban environment

AbstractAnalytical procedures of collection and sample preparation of micro‐ and nanoparticles from urban environment as well as results of analyses are presented. Particulate matter is collected from indoor and outdoor urban air by several methods using mechanical collectors: personal cascade impactor and quartz filters. The other method treats human organisms as collectors: the method is based on induced sputum. Elemental analysis of the collected material performed by spark‐source mass spectrometry (SSMS) on magnetic sector JEOL JMS‐1BM2 mass analyzer, gives concentration of over 20 elements with ppb sensitivity. SIMS depth profile analysis is performed on SAJW‐05 apparatus with quadrupole QMA‐410 analyzer and Physical Electronics ion gun. Indium substrate covered with particulate matter is scanned with 100 µm diameter 5 keV Ar+ ion beam. Particles collected by cascade impactor were deposited at indium substrates. Four aerodynamic diameter classes were analyzed, i.e. 10–2.5 µm, 2.5–1 µm, 1–0.5 µm and 0.5–0.25 µm. Depth profile analysis was performed up to 100 nm depth of eroded material. Results were obtained on sets of particles, and the measured secondary ion currents gave integral values of the analyzed material. Assuming average surface composition of the analyzed particles some hints on the compositional morphology of the type of ‘core‐shell’ are extracted. Obtained data on the bulk elemental composition and SIMS depth profile results show the dependence on the grain size. Copyright © 2010 John Wiley & Sons, Ltd.

スパークソース質量分析装置による環境生物試料（米）の多元素分析

スパークソース質量分析装置による環境生物試料（米）の多元素分析

Analysis of germanium and germanium dioxide samples by mass-spectrometry and atomic emission spectroscopy

Three multielement methods: (1) inductively coupled plasma mass spectrometry (ICP-MS), (2) inductively coupled plasma atomic emission spectroscopy (ICP-AES), and (3) spark source mass spectrometry (SSMS) were used for the determination of additives in the samples of germanium and germanium oxide. The detection limits of direct SSMS and ICP-AES/ICP-MS were compared using the autoclave predissolution of germanium and germanium dioxide samples. It was shown that in the latter case, the detection limits could be significantly improved by the separation of germanium from analytes by distillation. In this case, the detection limits of such limiting elements like Th and U can reach the level n 10−10 wt %.

Metallic impurities in germanium tetrafluoride and germanium dioxide prepared from it

The composition and contents of metallic impurities (in nonvolatile form) in isotopically unmodified and 76Ge-depleted germanium tetrafluoride samples were determined by chemical atomic emission spectrometry. The germanium tetrafluoride samples were then converted to germanium dioxide. The impurity compositions of the resultant germanium dioxide samples were determined by laser mass spectrometry, atomic emission spectrometry, inductively coupled plasma mass spectrometry, and spark source mass spectrometry.

Taxonomic units, civilization, volcanism: Their influence on the chemical composition of ostracod carapaces (Kagoshima Bay, Kyushu Island, Japan)

To test the influence of both civilization and volcanism on the chemical composition of ostracod carapaces, 32 well-preserved valves from Kagoshima Bay (Kyushu Island, South Japan) were analysed by means of spark source mass spectrometry. In Kagoshima Bay, the extent of pollution corresponds to human activities. Kagoshima Bay is also an area of important volcanic activity: emissions from Sakurajima volcano are very frequent. The species analysed were Argilloecia hanaii, Callistocythere undulatifacialis, Pontocythere subjaponica and Loxoconcha tosaensis. Twenty-three chemical elements were detected. Among them, 11 were always above the limit of detection: Al, B, Cl, F, Fe, K, Na, P, S, Si and Zn. The correlation between Zn and Fe was characteristic of the volcanic environment. Two discriminant analyses were performed using either the location area or the species as grouping variables. An association between Zn and S is possible; it could be related to volcanic activity. The chemical composition of carapaces is ascribed to taxonomic units rather than the environment.

Comparison of urban and rural particulate air pollution characteristics obtained by SIMS and SSMS

Aerosol particles were collected in different environments in Poland—in Legnica, a middle size town situated close to big copper works and in a rural site in the suburbs of Kraków, the city three times bigger than Legnica. Bulk analysis of particulate matter collected on quartz-fibre filters was performed using spark source mass spectrometry (SSMS). Analysis of airborne particles from urban and rural environments revealed differences in partial concentration of 20 selected elements. In urban aerosol collected in Legnica we found more: Pb, Cr—20 times than in the rural environment, As, Sr—10 times, Co—7 times, Cl—5 times, V, Y—3 times, Ti, Mn, Cu, Se—2 times and Fe, Ni, Zn, Br, Zr, Mo almost 2 times more than in the rural environment. Secondary ion mass spectrometry (SIMS) depth profile analyses were performed for aerosol particles collected at Al-foils with the use of nine-stage rotating plates cascade impactor. SIMS results obtained with the use of 5 keV Ar + ion sputtering show “core-shell” structure of urban and rural particles dependent of their grain size in the range of 300 nm to 15 μm. Ultra fine (300–500 nm diameter) rural particles have shell layers enriched in iron and manganese, while such enrichment is typical for coarse (5–10 μm diameter) urban particles.

Ion beam analysis of urban aerosol micro and nanoparticles compared with environmentally related children diseases in two Polish towns

Urban aerosol particles were collected in two Polish towns—Legnica and Starachowice, and characterised with mass spectrometry methods. Bulk analysis of particulate matter collected on quartz fibre filters was performed using spark source mass spectrometry (SSMS). Analysis of chosen elements revealed the differences in total concentrations in the towns. We found in Legnica more: Sr—5 times with respect to Starachowice, Se, As—3 times, Cl, V, Y, Mo—2 times, Cr, Fe, Ni, Cu, Rb i Pb—less than 2 times. In Starachowice we found more: Ti—40 times, Zn—5 times, Mn—2 times, Br, Co i Zr—less than 2 times. Another technique—secondary ion mass spectrometry (SIMS) allowed us to perform depth profile analysis of collected particles on aluminium plates of cascade impactor. The SIMS results showed “core-shell” structure of particles dependent on their grain size in the range of 300 nm to 15 μm. The shell layer was enriched in Cr, Cu and Pb. The results were compared with the medical study of the prevalence of environmentally related children diseases observed in these two cities. Questionnaire studies and allergic skin prick tests were performed according to the protocol of International Study of Asthma and Allergies in Childhood (ISAAC). An epidemiological study performed on Legnica and Starachowice children shows statistically similar results besides the compositional and morphological differences of particles suspended in the air of the two towns.

Morphology of micro- and nanoparticles emitted by copper plants in Western Poland

Aerosol particles were collected in the vicinity of copper plants in Western Poland and analysed by mass spectrometry methods like secondary ion mass spectrometry (SIMS), spark source mass spectrometry (SSMS) and X-ray diffraction to characterise the possible dangers for the environment and health. The motivation of the work was to approach the toxicological mechanisms that are triggered when aerosol nanoparticles enter the human body. Different analytical techniques were used in order to compare bulk and surface properties of particles. The particle collection was performed with nine-stage cascade impactor with rotating plates and also with micro-fibre quartz filter collector. SSMS bulk analysis of copper plant emitted particles shows the presence of over 30 elements, the concentration in wt.% of Cu, Pb, Zn and Cl is 30, 5, 2 and 1, respectively. XRD analysis of these particles shows crystalline phases of quartz and probable phases containing copper CuS 2, lead Pb 2SiO 4, PbO – massicot, Pb 5[OH][PO 4] 3, Pb 3SiO 5, iron and calcium Ca[Mg 0.67Fe 0.33][CO 3] – dolomite, ferroan, Ca[FeMg][CO 3] 2 – ankerite, Ca[MgFe]Si 2O 6 – augite. Surface sensitive SIMS depth profile analysis revealed the core-shell structure of copper plant emitted particles. The obtained structure of these particles shows that surfaces of the particles are enriched in elements like chlorine, fluorine, lead and chromium with respect to the core concentrations of these elements. The cores are composed mainly of copper, oxygen and carbon containing compounds. Lead concentration is nearly two times greater at the surface layers of particles than in the cores. SIMS analysis of urban aerosol particles collected in Legnica shows compositional dependence with size. Surface shell layer concentration of lead is three times greater for coarse 6–15 μm particles than for tiny 300 nm–1 μm particles. Such non-uniform particle morphology may enhance the toxic properties of particles suspended in air.

Richard Edward Honig

Richard Edward Honig, a physicist who spent his career at RCA Laboratories in Princeton, New Jersey, died of cancer on 31 July 2001 in Haverford, Pennsylvania. He investigated the vaporization of solids and was a pioneer in the design of mass spectral techniques for the characterization of solid surfaces. Rick was born on 4 June 1917 in Göttingen, Germany. In 1933, his father, a professor of law at Göttingen University, moved the family to Istanbul, Turkey. There, Rick attended Robert College and graduated in 1938 with a BS in electrical engineering. He went on to MIT, receiving his MS in electrical engineering in 1939 and his PhD in molecular physics in 1944. His thesis at MIT, prepared under the guidance of Clark Goodman, involved mass spectrometric studies of light hydrocarbons.During Rick’s years as a graduate student, his interest in mass spectrometry emerged and developed into a passion that he would sustain for the rest of his life. After a brief four-year stint at Socony-Vacuum Oil Co (the predecessor of Mobil Oil Corp) in Paulsboro, New Jersey, Rick joined the research staff at RCA’s David Sarnoff Research Center (now the Sarnoff Corp) in Princeton in 1950. In 1951, he proposed studying the physical sputtering process using a mass spectrometer. With the help of RCA’s extensive machine shop capabilities, Rick constructed a 180° magnetic sector instrument. Thus began a long and productive period in Rick’s career during which he conducted fundamental experiments in secondary ion mass spectrometry (SIMS). In addition to SIMS, Rick used his early mass spectrometer to study the vaporization of many elements of interest to the electronics industry during the 1950s.During his sabbatical (1955–56) at the Free University in Brussels, Belgium, Rick continued to pursue his interests in the mass spectral characterization of solids vaporization. Rick’s concern with vapor pressure prompted him in 1957 to evaluate the information available at the time and publish the assembled data in chart form, which he updated in 1962 and 1969. His “vapor pressure charts” were instantly popular and continue to be displayed in many textbooks and laboratories throughout the world. His fundamental interest in solids analysis took his research into the areas of spark source mass spectrometry and laser desorption mass spectrometry. Rick and his RCA colleagues made many original and significant contributions to these fields as well. Among these are energy distributions of ions formed in the radio frequency spark source and the response of ion-sensitive plates for mass spectrography.Rick became head of RCA Laboratories’ newly reorganized materials characterization group in 1966 and held this position for the next 16 years. He built the group, directed its research, and promoted the careers of the group’s professional staff and technical associates. Under Rick’s leadership, RCA developed one of the most advanced and well-respected materials characterization laboratories in the world.Rick was an active participant in the activities of the American Society for Testing and Materials during the 1960s. He also was one of the founding fathers of the American Society for Mass Spectrometry and served as the society’s first vice president for programs (1968–70) and as its second president (1970–72).As a young man, Rick especially enjoyed gymnastics, ice skating, and tennis. In his later years, he enjoyed day outings and hiking with his family in the mountains of Switzerland and his native Germany. A longtime resident of Princeton, he was chairman of the language committee at the Princeton Adult School for many years.Rick’s friends and colleagues remember him with the greatest admiration and deepest appreciation for a lifetime devoted to the pursuit of scientific truth. His family and friends sorely miss him.Richard Edward HonigPPT|High resolution© 2002 American Institute of Physics.

Analysis of silicon incorporation into VGF-grown GaAs

The incorporation of silicon into VGF-grown GaAs is examined by Hall effect measurements, spark source mass spectrometry and photoluminescence (PL). It is found that the silicon is incorporated into the crystal according to Scheils-law with the Si concentration [Si] rising from 1.5×10 18 to 1×10 19 cm −3. It is found that the intensity of the PL peak with energy close to the band gap decreases with increasing Si content of the material, whereas the intensity of the PL peak related to the acceptor Si GaV Ga shows opposite behaviour. A compensation model which takes into account the acceptors Si As and Si GaV Ga is developed. The model describes the relationship between [Si] and the charge carrier concentration n up to silicon concentrations of 1×10 19 cm −3 in GaAs grown under low thermal gradients.

Morphology of working environment microparticles

Depth resolved analyses of industrial microparticles collected in the working environment of steelworks and glass plant are presented. Grain size distributions of aerosol microparticles were estimated using the eight-stage cascade impactor with the particle size range of 0.2–15μm. Bulk analysis of the collected dust particles was performed using the spark source mass spectrometry and X-ray diffraction methods. The morphology, i.e. the elemental structure of collected sub-micrometer particles was described due to ion sputtering experiments using secondary ion mass spectrometry (SIMS) depth profiling. These analyses were performed on the two SIMS instruments: on SAJW-02 equipped with Balzers 16mm quadrupole spectrometer using 4keV Ar+ and O2+ ion beam and also on IMS-3F Cameca using 12keV O2+ ion beam. The obtained results show that the sub-micrometer particles do not have uniform morphology. The core-shell structure has been observed for particles collected in both factories. The presented models show that steelworks particles consist mainly of iron and manganese cores. At the shells of these microparticles lead, chlorine and fluorine are found. The particles collected in the glass plant consist mainly of lead–zirconium glass cores covered by carbon and copper. The sample rotation technique applied in SIMS appears to be an effective tool for environmental microparticle morphology studies.

Progress in multi-ion counting spark-source mass spectrometry (MIC-SSMS) for the analysis of geological samples.

Spark source mass spectrometry (SSMS) has experienced important and significant improvements in nearly all analytical features by the use of a multiple ion counting (MIC) system. Two procedures have recently been developed to further increase the analytical capabilities of MIC-SSMS in geochemistry. These are a mathematical correction of interferences, which is often necessary for the ultra trace element analysis of Nb, Ta, Zr, Hf and Y, and the development of an autospark system to hold the total ion beam constant. New analytical data for geological samples, especially international reference materials, are presented using the improved MIC-SSMS technique. The data set consists of high precision and low abundance data for Zr, Nb and Y in depleted reference materials. The MIC-SSMS results are compared with those of conventional SSMS using photoplates for ion detection. The precision of the MIC-SSMS isotope ratio measurements (about 1%) is more than a factor of 3 better than that of conventional SSMS, as demonstrated by analyses of Hawaiian samples. Total uncertainties of MIC-SSMS concentration data including all sources of error are generally between 2 and 5% for concentrations higher than about 0.3 microg/g and about 10% for trace element abundances in the ng/g range.

High‐Precision Trace Element Data for the USGS Reference Materials BCR‐1, BCR‐2, BHVO‐1, BHVO‐2, AGV‐1, AGV‐2, DTS‐1, DTS‐2, GSP‐1 and GSP‐2 by ID‐TIMS and MIC‐SSMS

Different batches of the new US Geological Survey (USGS) reference materials (RMs) BCR‐2, BHVO‐2, AGV‐2, DTS‐2 and GSP‐2 and the original USGS RMs BCR‐1, BHVO‐1, AGV‐1, DTS‐1 and GSP‐1 have been analysed by isotope dilution using thermal ionisation mass spectrometry (ID‐TIMS) and by multi‐ion counting spark source mass spectrometry (MIC‐SSMS). The concentrations of K, Rb, Sr, Ba and the rare earth elements were determined with overall analytical uncertainties of better than 1% (ID‐TIMS) and 3% (MIC‐SSMS). The analyses of different aliquots and batches of BCR‐2, BHVO‐2, AGV‐2 and GSP‐2, respectively, agree within 1%, i.e. approximately the analytical uncertainties of the data. This indicates an homogeneous distribution of the trace elements in these RMs. Differences in element concentrations of up to 17% in different aliquots of the depleted RM DTS‐2 are outside the analytical uncertainty of our data. They may be attributed to a slightly heterogeneous distribution of trace elements in this dunite sample. Our trace element data for BCR‐2, BHVO‐2, AGV‐2 and GSP‐2 agree within about 3% with preliminary reference values published by the USGS. They also agree within 1‐6% with those of the original RMs BCR‐1, BHVO‐1, AGV‐1 and GSP‐1. Large compositional differences are found between DTS‐2 and DTS‐1, where the concentrations of K, Rb, Sr and the light REE differ by factors of 2 to 24.

Determination of trace zirconium and hafnium in basaltic rocks by inductively coupled plasma atomic emission spectrometry after chemical separation: an evaluation of two methods based on extraction chromatography

The determination of Zr and Hf in basaltic rocks by inductively coupled plasma atomic emission spectrometry after extraction chromatographic separation is reported. Two different approaches were employed using tricaprylylmethylammonium chloride (Aliquat 336) and N-benzoyl-N-phenylhydroxylamine (BPHA) as stationary phases supported on inert porous polymeric substrates. The major advantages of the separation schemes are simplicity and the easy separation of Zr and Hf from Ti, a major element in rocks. The BPHA approach is superior to the Aliquat 336 approach with regard to sample preparation and separation conditions. The method yields detection limits of 0.02 and 0.07 μg g−1 for Zr and Hf, respectively. The analytical results for international reference rock materials (BIR-1, W-2, BHVO-1) showed excellent agreement with literature values obtained by spark source mass spectrometry and inductively coupled plasma mass spectrometry. The relative standard deviations were in the range 2–4% for the samples analysed.

Analysis of Electrically Active Carbon in Semi-insulating Gallium Arsenide by Infrared Absorption Spectroscopy

Carbon in semi-insulating gallium arsenide (GaAs) crystals has been investigated by Fourier-transform IR absorption spectroscopy, spark source mass spectrometry, and charged particle activation analysis. Procedures for the quantitative evaluation of the 582-cm-1 local mode absorption due to carbon on the arsenic sublattice (CAs) are described. The strength of the mode shows a linear correlation with total carbon content measured by spark source mass spectrometry over the concentration range from 3× 1014 to 2×1016 cm-3. The new calibration factor for the integrated absorption at 77 K is (7.2±0.4)× 1015 cm-1, based on a relative sensitivity coefficient of 3.2±0.1 of the spark source mass spectrometry. Calibration factors for the IR absorption method at room temperature are also given.