Sign In |Help & Support
ALL SECTORS
  • ALL SECTORS
  • GB(National Standard)
  • CB(Shipping)
  • CECS(Engineering Construction)
  • CJ(Urban Construction)
  • CY(News and Publication)
  • DB(Provincial Standard)
  • DL(Electricity & Power)
  • DZ(Geology & Mineralogy)
  • FZ(Spinning & Textile)
  • GA(Public Security)
  • HB(Aviation)
  • HG(Chemical Industry)
  • HJ(Environmental Protection)
  • JB(Machinery)
  • JC(Building Materials)
  • JG(Building & Construction)
  • JJ(Metering)
  • JT(Highway & Transportation)
  • LY(Forestry)
  • MT(Coal)
  • NB(Energy)
  • NY(Agriculture)
  • QB(Light Industry)
  • QC(Automobile & Vehicle)
  • QJ(Aerospace)
  • SH(Petrochemical)
  • SJ(Electronics)
  • SL(Water Resources)
  • SN(Commodity Inspection)
  • SY(Oil & Gas)
  • TB(Railway & Train)
  • YB(Ferrous Metallurgy)
  • YC(Tobacco)
  • YD(Telecommunication)
  • YY(Medical Device)
Database: 365,228(8 Aug 2026)

What does atomic absorption measure

What does atomic absorption measure, Total:200 items.

The international standard classification for "What does atomic absorption measure" includes: Analytical chemistry in general , Cadmium, cobalt and their alloys .

The Chinese standard classification for "What does atomic absorption measure" includes: Electrochemical, thermochemistry and optical profile type analyzer , Heavy metals and their alloys analysis method , Electron optics and other physical optics instrument .


National Metrological Verification Regulations of the People's Republic of China

  • JJG 679-1990 Verification Regulation of cold Atomic Absorption Analyzer of Mercury
  • JJG 694-1990 Atomic Absorption Spectrophotometer

General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China

Professional Standard - Non-ferrous Metal

  • YS/T 536.4-2009 Methods for chemical analysis of bismuth - Determination of silver content - Flame atomic absorption spectrophotometric method and electrothermal atomic absorption spectrometric method

Professional Standard - Machinery

Institute of Interconnecting and Packaging Electronic Circuits (IPC)

American Gear Manufacturers Association

Czech Standards Institute (UNMZ)

  • CSN 42 0621 Cast.49-1983 Copper. Determination of iron by the atomic absorption method
  • CSN 42 0621 Cast.42-1983 Copper. Determination of lead by the atomic absorption method
  • CSN 42 0647 Cast.10-1989 Chemical analysis of non-ferrous metals and alloys. Tungsten. Determination of copper by the atomic absorption method
  • CSN 42 0647 Cast.11-1989 Chemical analysis of non-ferrous metals and alloys. Tungsten. Determination of manganese by the atomic absorption method
  • CSN 42 0647 Cast.7-1989 Chemical analysis of non-ferrous metals and alloys. Tungsten. Determination of sodium by the atomic absorption method
  • CSN 42 0621 Cast.50-1983 Copper. Determination of zinc by the atomic absorption method
  • CSN 42 0647 Cast.4-1989 Chemical analysis of non-ferrous metals and alloys. Tungsten. Determination of nickel by the atomic absorption method
  • CSN 42 0646 Cast.9-1989 Chemical analysis of non-ferrous metals and alloys. Molybdenum. Determination of sodium by the atomic absorption method
  • CSN 42 0621 Cast.52-1983 Copper. Determination of antimony by the atomic absorption method
  • CSN 42 0621 Cast.48-1983 Chemical analysis of non-ferrous metals and alloys. Copper. Determination of bismuth by the atomic absorption method
  • CSN 42 0621 Cast.51-1983 Chemical analysis of non-ferrous metals and alloys. Copper. Determination of nickel by the atomic absorption method
  • CSN 42 0621 Cast.46-1983 Copper. Determination of tin by the atomic absorption method
  • CSN 42 0635 Cast.12-1986 Chemical analysis of non-ferrous metals and alloys. Lead. Determination of silver by the atomic absorption method
  • CSN 42 0635 Cast.10-1986 Chemical analysis of non-ferrous metals and alloys. Lead. Determination of zinc by the atomic absorption method
  • CSN 42 0646 Cast.10-1989 Chemical analysis of non-ferrous metals and alloys. Molybdenum. Determination of nickel by the atomic absorption method
  • CSN 42 0635 Cast.11-1986 Chemical analysis of non-ferrous metals and alloys. Lead. Determination of bismuth by the atomic absorption method
  • CSN 42 0635 Cast.13-1986 Chemical analysis of non-ferrous metals and alloys. Lead. Determination of copper by the atomic absorption method
  • CSN 42 0621 Cast.44-1983 Chemical analysis of non-ferrous metals and alloys. Copper. Determination of silver by the atomic absorption method
  • CSN 42 0622 Cast.18-1981 Chemical analysis of non-ferrous metals and alloys. Bronzes. Determination of magnesium by the atomic absorption method
  • CSN 42 0635 Cast.16-1987 Chemical analysis of non-ferrous metals and alloys. Lead. Determination of calcium by the atomic absorption method
  • CSN 42 0647 Cast.8-1989 Chemical analysis of non-ferrous metals and alloys. Tungsten. Determination of calcium by the atomic absorption method
  • CSN 42 0641 Cast.23-1986 Chemical analysis of non-ferrous metals and alloys. Nickel alloys. Determination of molybdenum by the atomic absorption method
  • CSN 42 0647 Cast.9-1989 Chemical analysis of non-ferrous metals and alloys. Tungsten analysis. Determination of magnesium by atomic absorption method
  • CSN 42 0635 Cast.14-1987 Chemical analysis of non-ferrous metals and alloys. Lead. Determination of magnesium by the atomic absorption method
  • CSN 42 0646 Cast.8-1989 Chemical analysis of non-ferrous metals and alloys. Molybdenum. Determination of magnesium by the atomic absorption method
  • CSN 42 0640 Cast.9-1982 Chemical analysis of non-ferrous metals and alloys. Nickel. Determination of magnesium by the atomic absorption method
  • CSN 42 0646 Cast.7-1989 Chemical analysis of non-ferrous metals and alloys. Molybdenum. Determination of calcium by the atomic absorption method
  • CSN 42 0636 Cast.7-1983 Chemical analysis of non-ferrous metals and alloys. Lead-antimony alloys. Determination of zinc by the atomic absorption method
  • CSN 42 0636 Cast.8-1983 Chemical analysis of non-ferrous metals and alloys. Lead-antimony alloys. Determination of silver by the atomic absorption method
  • CSN 42 0636 Cast.13-1991 Lead-antimony alloys. Determination of arsenic by the atomic absorption method
  • CSN 42 0669 Cast.3-1985 Chemical analysis of non-ferrous metals and alloys. Cobalt. Determination of iron by the atomic absorption method and photometric method
  • CSN 42 0641 Cast.9-1984 Chemical analysis of non-ferrous metals and alloys. Nickel alloys. Determination of magnesium by the atomic absorption method
  • CSN 42 0671 Cast.4-1980 Aluminium. Determination of cooper by the photometric method and atomic absorption method
  • CSN 42 0633 Cast.7-1979 Cadmium. Determination of thallium by the atomic absorption mothod and polarographic method
  • CSN 42 0645 Cast.6-1987 Chemical analysis of non-ferrous metals and alloys. Antimony. Determination of nickel by the polarographic method and atomic absorption method
  • CSN 42 0647 Cast.1-1989 Chemical analysis of non-ferrous metals and alloys. Tungsten. Determination of molybdenum by the photometric method and atomic absorption method
  • CSN 42 0680 Cast.4-1986 Chemical analysis of non-ferrous metals and alloys. Tin. Determination of copper by the photometric method and atomic absorption method
  • CSN 42 0640 Cast.8-1982 Nickel. Determination of cobalt by the photometrie methods and atomic absorption method
  • CSN 42 0647 Cast.3-1989 Chemical analysis of non-ferrous metals and alloys. Tungsten. Determination of aluminum by the photometric method and atomic absorption methods
  • CSN 42 0669 Cast.4-1985 Chemical analysis of non-ferrous metals and alloys. Cobalt. Determination of manganese by the atomic absorption method and photometric method
  • CSN 42 0640 Cast.6-1982 Nickel Determination of cadmium by the polarographic method and atomic absorption method
  • CSN 42 0646 Cast.4-1989 Chemical analysis of non-ferrous metals and alloys. Molybdenum. Determination of copper by the photometric method and atomic absorption method
  • CSN 42 0640 Cast.10-1982 Xickel. Determination of copper by the photometric method and atomic absorption method
  • CSN 42 0633 Cast.4-1979 Chemical analysis of non-ferrous metals and alloys. Cadmium. Determination of iron by the atomic absorption method and polarographic method
  • CSN 42 0614-2-1994 Lead-tin base alloys. Determination of tin by the atomic absorption method
  • CSN 42 0614-17-1994 Lead and tin base alloys. Determination of zinc by the atomic absorption method
  • CSN 42 0614-6-1994 Lead and tin base alloys. Determination of cooper by the atomic absorption method
  • CSN 42 0614-11-1994 Lead-tin base alloys. Determination of silver by the atomic absorption method
  • CSN 42 0614-16-1994 Lead and tin base alloys. Determination of arsenic by the atomic absorption method
  • CSN 42 0614-5-1994 Lead - tin base alloys. Determination of lead by the atomic absorption method
  • CSN 42 0611 Cast.5-1986 Chemical analysis of non-ferrous metals. Copper-base bearing metals. Determination of zinc by the atomic absorption method
  • CSN 42 0646 Cast.2-1989 Chemical analysis of non-ferrous metals and alloys. Molybdenum. Determination of aluminum by the photometric method and atomic absorption method
  • CSN 42 0640 Cast.20-1985 Nickcl. Determination of silver by the atomic absorption method and photometric method
  • CSN 42 0669 Cast.1-1985 Chemical analysis of non-ferrous metals and alloys. Cobalt. Determination of nickel by the atomic absorption method and photometric method
  • CSN 42 0645 Cast.1-1987 Chemical analysis of non-ferrous metals and alloys. Antimony. Determination of lead by the polarographic method and atomic absorption method
  • CSN 42 0640 Cast.13-1982 Nickel. Determination of lead by the photometric methods and atomic absorption method
  • CSN 42 0646 Cast.3-1989 Chemical analysis of non-ferrous metals and alloys. Molybdenum. Determination of manganese by the photometric method and atomic absorption methods
  • CSN 42 0614-3-1994 Lead-tin base alloys. Determination of antimony by the atomic absorption method
  • CSN 42 0614-8-1994 Lead-tin base alloys. Determination of bismuth by the atomic absorption method
  • CSN 42 0614-13-1994 Lead and tin base alloys. Determination of iron by the atomic absorption method
  • CSN 42 0645 Cast.8-1987 Chemical analysis of non-ferrous metals and alloys. Antimony. Determination of zinc by the polarographic method and atomic absorption method
  • CSN 42 0633 Cast.9-1979 Chemical analysis of non-ferrous metals and alloys. Cadmium. Determination of nickel by the atomic absorption method and photometric method
  • CSN 42 0680 Cast.5-1986 Chemical analysis of non-ferrous metals and alloys. Tin. Determination of lead by the polarographic method and atomic absorption method
  • CSN 42 0633 Cast.2-1979 Chemical analysis of non-ferrous metals and alloys. Cadmium. Determination of zinc by the atomic absorption method and polarographic method
  • CSN 42 0669 Cast.2-1985 Chemical analysis of non-ferrous metals and alloys. Cobalt. Determination of copper by the atomic absorption method and photometric method
  • CSN 44 1776-1988 Lead concentrates. Determination of cadmium content
  • CSN 42 0645 Cast.9-1987 Chemical analysis of non-ferrous metals and alloys. Antimony. Determination of manganese by the photometric method and atomic absorption method
  • CSN 42 0680 Cast.9-1986 Chemical analysis of non-ferrous metals and alloys. Tin. Determination of zinc by the polarographic method and atomic absorption method
  • CSN 42 0640 Cast.17-1982 Nickel. Determination of ziao by the polarographic method and atomic absorption method
  • CSN 42 0614-19-1994 Lead and tin base alloys. Determination of cadmium by the atomic absorption method
  • CSN 42 0640 Cast.11-1982 Nickel. Determination of manganese by the photometric method and atomic absorption method
  • CSN 42 0633 Cast.3-1979 Chemical analysis of non-ferrous metals and alloys. Cadmium. Determination of lead by the atomic absorption method and polarographic method
  • CSN 42 0647 Cast.6-1989 Chemical analysis of non-ferrous metals and alloys. Tungsten. Determination of lead by the photometric and atomic absorption method
  • CSN 42 0614-21-1994 Lead and tin base alloys. Determination of nickel by the atomic absorption method
  • CSN 65 1058-1983 Aluminium oxide. Determination of alcium oxide. The atomie absorption ethod.
  • CSN 42 0647 Cast.2-1989 Chemical analysis of non-ferrous metals and alloys. Tungsten. Determination of iron by the photometric method and atomic absorption methods
  • CSN 42 0633 Cast.5-1979 Chemical analysis of non-ferrous metals and alloys. Cadmium. Determination of copper by the atomic absorption method and photometric method
  • CSN 42 0646 Cast.1-1989 Chemical analysis of non-ferrous metals and alloys. Molybdenum. Determination of iron by the photometric method and atomic absorption methods
  • CSN 42 0620 Cast.6-1981 Chemical analysis of non-ferrous metals and alloys. Brasses. Determination of iron by the photometric methods and atomic absorption method
  • CSN 44 1877-1982 Bauxite. Determination of coppric oxide The atomic absorption method.

Indonesia Standards

  • SNI 06-2428-1991 Air, Metode pengujian atom dengan spektrofotometer serapan atom
  • SNI 13-6180-1999 Procedure for optimization of flame Atomic Absorption Spectrophotometer (AAS)

GCC Standardization Organization

  • GSO ISO 9174:2007 Water quality – Determination of chromium – Atomic absorption spectrometric method
  • GSO ISO 9965:2007 Water quality – Determination of selenium – Atomic absorption spectrometric method (hydride technique)
  • GSO ISO 12020:2013 Water quality -- Determination of aluminium -- Atomic absorption spectrometric methods
  • BH GSO ISO 9174:2024 Water quality – Determination of chromium – Atomic absorption spectrometric method
  • GSO ISO 7980:2013 Water quality - Determination of calcium and magnesium - Atomic absorption spectrometric method

Gosstandart of Russia

  • GOST 31266-2004 Raw materials and food products. Atomic absorption method for determination of arsenic
  • GOST 23957.2-1980 Zinc. Atomic-absorbic method for the determination of tin
  • GOST 23957.2-2003 Zinc. Atomic-absorption method for determination of tin
  • GOST R 51766-2001 Raw material and food-stuffs. Atomic absorption method for determination of arsenic
  • GOST 28353.3-1989 Silver. Method of atomic-absorption analysis
  • GOST 26880.1-1986 Lead. Atomic-absorption methods of analysis
  • GOST 27973.3-1988 Gold. Method of atomic-absorption analysis
  • GOST 28353.3-2017 Silver. Method of atomic-absorption analysis
  • GOST 14048.18-1999 Zinc concentrates. Atomic-absorbic method for determination of manganese and cobalt
  • GOST 23957.1-2003 Zinc. Atomic-absorption method for determination of lead, cadmium, antimony, iron and copper
  • GOST 28612-1990 Fodder methionine. Atomic-absorption method for determination of mercury
  • GOST R 52124-2003 Zink concentrates. Atomic absorption method for determination of arsenic
  • GOST 32350-2024 Gasolines. Determination of lead by atomic absorption spectrometry
  • GOST R 56308-2014 Silver. Method of atomic-absorption analysis
  • GOST 23957.1-1980 Zinc. Atomic-absorbic method for the determination of lead, cadmium, antimony, iron and copper
  • GOST R 56633-2015 Bee products. Atomic absorption method for determination of arsenic
  • GOST 28407.6-1989 Bismuth concentrate. Atomic absorption method for determination of silver

American Water Works Association (AWWA)

  • AWWA WQTC62615 What is the Cause of Turbidity in a Groundwater under the Influence of Surface Water Plant?
  • AWWA ACE69127 Why Do We Monitor: Drawdown, Or Drainage and Drought?

German Institute for Standardization

  • DIN EN 16197:2013-01 Fertilizers - Determination of magnesium by atomic absorption spectrometry; German version EN 16197:2012
  • DIN 51401:2010 Atomic absorption spectrometry (AAS) - Vocabulary
  • DIN EN ISO 12020:2000-05 Water quality - Determination of aluminium - Atomic absorption spectrometric methods (ISO 12020:1997); German version EN ISO 12020:2000
  • DIN EN 1233:1996-08 Water quality - Determination of chromium - Atomic absorption spectrometric methods; German version EN 1233:1996
  • DIN EN 1483:2007 Water quality - Determination of mercury - Method using atomic absorption spectrometry; English version of DIN EN 1483:2007-07
  • DIN EN 1483:1997 Water quality - Determination of mercury - Method using atomic absorption spectrometry
  • DIN EN 1483:2007-07 Water quality - Determination of mercury - Method using atomic absorption spectrometry

British Standards Institution (BSI)

  • PD CEN/TS 16197:2011 Fertilizers - Determination of magnesium by atomic absorption spectrometry
  • DD CEN/TS 16197:2011 Fertilizers. Determination of magnesium by atomic absorption spectrometry
  • BS EN ISO 5961:1995 Water quality. Determination of cadmium by atomic absorption spectrometry
  • BS EN ISO 5961:1995(2008)*BS 6068-2.21:1995 Water quality — Determination of cadmium by atomic absorption spectrometry
  • BS EN 1483:2007 Water quality - Determination of mercury - Method using atomic absorption spectrometry
  • BS EN ISO 12020:2000(2008) Water quality - Determination of aluminium - Atomic absorption spectrometric methods
  • BS EN 1233:1997 Water quality. Determination of chromium. Atomic absorption spectrometric methods
  • BS ISO 6323-1:2024 Workplace air. Determination of arsenic and arsenic compounds by electrothermal atomic absorption spectrometry - Arsenic and arsenic compounds, except arsine by ET-AAS

Standard Association of Australia (SAA)

  • AS 2134.3:1994(R2016) Recommended practice for chemical analysis by atomic absorption spectrometry - Vapour generation atomic absorption spectrometry
  • AS 2134.3:1994 Recommended practice for chemical analysis by atomic absorption spectrometry - Vapour generation atomic absorption spectrometry
  • AS 2134.1:1999(R2016) Recommended practice for chemical analysis by atomic absorption spectrometry - Flame atomic absorption spectrometry
  • AS 2134.1:1999 Recommended practice for chemical analysis by atomic absorption spectrometry - Flame atomic absorption spectrometry
  • AS 2134.1:1988 Recommended practice for chemical analysis by atomic absorption spectrometry - Flame atomic absorption spectrometry

Danish Standards Foundation

Bureau of Indian Standards

  • IS 9958-1981 Determination of Zinc by Atomic Absorption Spectrophotometry
  • IS 16721-2-2018 Method of Test for Coal Part 2 Determination of Arsenic and Selenium - Eschka's Mixture and Hydride Generation/ Atomic Absorption Spectrometry

Spanish Association for Standardization (UNE)

  • UNE-EN 16197:2013 Fertilizers - Determination of magnesium by atomic absorption spectrometry
  • UNE-EN 1233:1997 WATER QUALITY. DETERMINATION OF CHROMIUM. ATOMIC ABSORPTION SPECTROMETRIC METHODS.
  • UNE 36371-4:1986 DETERMINATION OF THE TIN COATING MASS. ATOMIC ABSORPTION METHOD
  • UNE-EN 1483:2007 Water quality - Determination of mercury - Method using atomic absorption spectrometry
  • UNE 7351:1975 DETERMINATION OF COPPER ALLOYS AND COPPER CONTENT BY ATOMIC ABSORPTION METHOD.

Swedish Institute for Standards

  • SS-EN 16197:2012 Fertilizers - Determination of magnesium by atomic absorption spectrometry
  • SS-EN 1233:1997 Water quality - Determination of chromium - Atomic absorption spectrometric method

Asociación Española de Normalización (AENOR)

Korean Agency for Technology and Standards (KATS)

  • KS I ISO 5961:2006 Water quality-Determination of cadmium by atomic absorption spectrometry
  • KS M 9104-1996 Water quality-Determination of cadmium by atomic absorption spectrometry
  • KS I ISO 5961-2021 Water quality — Determination of cadmium by atomic absorption spectrometry
  • KS I ISO 12020:2008 Water quality-Determination of aluminium-Atomic absorption spectrometric methods
  • KS I ISO 12020-2023 Water quality ― Determination of aluminium ― Atomic absorption spectrometric methods
  • KS I ISO 5961-2006(2016) Water quality-Determination of cadmium by atomic absorption spectrometry
  • KS I ISO 9174:2008 Water quality-Determination of total chromium-Atomic absorption spectrometric methods
  • KS M ISO 918:2017 Volatile organic liquids for industrial use-Determination of distillation characteristics
  • KS M ISO 918:2007 Volatile organic liquids for industrial use-Determination of distillation characteristics
  • KS I ISO 5961:2021 Water quality — Determination of cadmium by atomic absorption spectrometry
  • KS I ISO 12020-2008(2018) Water quality-Determination of aluminium-Atomic absorption spectrometric methods
  • KS M 0016-2010 General rules for atomic absorption spectrochemical analysis
  • KS I ISO 9174-2018 Water quality-Determination of total chromium-Atomic absorption spectrometric methods
  • KS I ISO 9174-2008(2018) Water quality-Determination of total chromium-Atomic absorption spectrometric methods

Association Francaise de Normalisation

COMMISSION FOR THE STANDARDS, METROLOGY AND QUALITY OF VIETNAM (STAMEQ)

  • TCVN 5399-1991 Gold.Methods of atomic absorption analysis
  • TCVN 6222-2008 Water quality.Determination of chromium.Atomic absorption spectrometric methods
  • TCVN 6657-2000 Water quality.Determination of alumimium.Atomic absorption spectrometric methods
  • TCVN 5383-1991 Crude oil.Determination of nikel content by atomic absorption spectroplotometry
  • TCVN 5732-1993 Crude oil.Determination of vanadium content by atomic absorption spectrocopy

International Organization for Standardization (ISO)

  • ISO 5961:1994 Water quality; determination of cadmium by atomic absorption spectrometry
  • ISO 9174:1998 Water quality - Determination of chromium - Atomic absorption spectrometric methods
  • ISO 12020:1997 Water quality - Determination of aluminium - Atomic absorption spectrometric methods
  • ISO 3750:1976 Zinc alloys; Determination of magnesium content; Atomic absorption method

Standards Norway

  • NS-EN 16197:2012 Fertilizers - Determination of magnesium by atomic absorption spectrometry
  • SN-CEN/TS 16197:2011 Fertilizers — Determination of magnesium by atomic absorption spectrometry
  • NS-EN 1233:1996 Water quality — Determination of chromium — Atomic absorption spectrometric methods
  • NS-EN 1483:2007 Water quality — Determination of mercury — Method using atomic absorption spectrometry

Ente Nazionale Italiano di Unificazione

  • UNI EN ISO 5961:1997 Water quality. Determination of cadmium by atomic absorption spectrometry.
  • UNI EN ISO 12020:2002 Water quality - Determination of aluminium - Atomic absorption spectrometric methods
  • UNI EN 1483:2008 Water quality - Determination of mercury - Method using atomic absorption spectrometry
  • UNI EN ISO 7980:2002 Water quality - Determination of calcium and magnesium - Atomic absorption spectrometric method

European Committee for Standardization (CEN)

  • EN 16197:2012 Fertilizers - Determination of magnesium by atomic absorption spectrometry
  • EN 1483:2007 Water quality - Determination of mercury - Method using atomic absorption spectrometry
  • EN 1233:1996 Water Quality - Determination of Chromium - Atomic Absorption Spectrometric Methods

Lithuanian Standards Office

  • LST EN 16197-2013 Fertilizers - Determination of magnesium by atomic absorption spectrometry
  • LST EN 1233-2000 Water quality - Determination of chromium - Atomic absorption spectrometric methods

Kingdom of Bahrain Testing and Metrology Directorate

  • BH GSO ISO 12020:2016 Water quality -- Determination of aluminium -- Atomic absorption spectrometric methods

GM North America

The Directorate General of Specifications and Metrology (DGSM)

  • OS GSO ISO 12020:2013 Water quality -- Determination of aluminium -- Atomic absorption spectrometric methods
  • OS GSO ISO 9174:2007 Water quality – Determination of chromium – Atomic absorption spectrometric method

South African Bureau of Standard

  • SANS 6265:2006 Water - Calcium and magnesium content - Atomic absorption spectrometric method