What is used to measure the fluorescence of liquids?
What is used to measure the fluorescence of liquids?, Total:159 items.
The international standard classification for "What is used to measure the fluorescence of liquids?" includes: Petroleum products in general , Products of the chemical industry in general , General methods of tests and analysis for food products , Environmental protection , Medical Sciences and health care facilities in general , Cosmetics. Toiletries , Analytical chemistry .
The Chinese standard classification for "What is used to measure the fluorescence of liquids?" includes: Petroleum products in general , Basic standards and general methods for dye , Basic standards and general methods , Analysis and test methods for radioactive substances and radiation intensity , Chemical additive , Basic standards and general methods , Diagnostic standard for public nuisance diseases , Cosmetics , Basic standards and general methods , Special electronic technology material .
Professional Standard - Nuclear Industry
- EJ/T 20189-2018 Liquid Fluorescence Method for Determination of Uranium Content in Low-Level Organic Waste Liquid
- EJ/T 20057-2014 Determination of uranium concentration in atmospheric fallout.Liquid fluorometry by ultraviolet
- EJ/T 296.2-2014 Determination of trace uranium in urine liquid fluorometry by ultraviolet
- EJ 296.2-1987 Analytical method of trace uranium in urine laser liquid fluorescence method
- EJ/T 20196-2018 Liquid Fluorescence Method for Determination of Uranium Content in Radioactive Metal Waste
General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China
- GB/T 11132-2002 STANDARD test method for hydrocarbon types in liquid petroleum products by fluorescent indicator adsorption
- GB/T 11223.1-1989 Analytical determination of uranium in ash of biological samples--Solid fluorimetry
- GB/T 11132-2022 Test method for hydrocarbon types in liquid petroleum products—Fluorescent indicator adsorption
- GB/T 21883-2008 Fluorescent whitening agents - Determination of fluoristrength
- GB/T 11132-2008 Standard test method for hydrocarbon types in liquid petroleum products by fluorescent indicator adsorption
- GB/T 11223.2-1989 Analytical determination of uranium in ash of biological samples—Laser liquid fluorimetry
- GB/T 21883-2016 Fluorescent whitening agents一Determination of fluoristrength
- GB/T 23217-2008 Determination of tetrodotoxin in aquatic products - HPLC-fluorescence detection method
中华人民共和国环境保护部
- GB 11223.1-1989 Analytical determination of uranium in ash of biological samples; Solid fluorimetry
- GB 11223.2-1989 Analytical determination of uranium in ash of biological samples--Laser liquid fluorimetry
Professional Standard - Chemical Industry
- HG/T 4432-2012 Liquid fluorescent whitening agent
中华人民共和国国家质量监督检验检疫总局、中国国家标准化管理委员会
- GB/T 33401-2016 Determination of the urea in liquid fluorescent whitening agent products
国家能源局
- SH/T 0842-2017 Determination of sulfur content in light liquid fuels by single-wavelength dispersive X-ray fluorescence spectrometry
Professional Standard - Energy
- NB/SH/T 0842-2017 Standard test method for sulfur in light liquid fuels by monochromatic wavelength dispersive X-ray fluorescence spectrometry
Shaanxi Provincial Standard of the People's Republic of China
- DB61/T 562-2013 Water Quality Determination of Alkyl Mercury by Liquid Chromatography-Atomic Fluorescence
- DB61/T 967-2015 Determination of Benzo[a]pyrene in Vegetable Oil by Liquid Chromatography-Fluorescence Detection
Professional Standard - Commodity Inspection
- SN/T 4396-2015 Determination of fluorescent whitening agent 85、fluorescent whitening agent 71 and fluorescent whitening agent 113 in foodstuffs for export―LC-MS/MS method
- SN/T 3822-2014 Determination of bisphenol A in cosmetics for export - Fluorescence detection method for liquid chromatogram
中华人民共和国国家卫生和计划生育委员会
- WS/T 92-1996 Blood—Determination of zinc protoporphyrin—Hematofluorometer method
卫生健康委员会
- WS/T 635-2018 Determination of urinary arsenic speciation - liquid chromatography-atomic fluorescence spectrometry
Group Standards of the People's Republic of China
- T/CAIA YQ004-2018 Performance testing method for liquid chromatograph coupled with atomic fluorescence spectrometer
- T/GXAS 767-2024 Determination of mercury in urine by hydride generation atomic fluorescence spectrometry
Jilin Provincial Standard of the People's Republic of China
- DB22/T 2464-2016 Determination of methylmercury in water by liquid chromatography-atomic fluorescence method
- DB22/T 2205-2014 Determination of Alkyl Mercury in Wastewater by Liquid Chromatography-Atomic Fluorescence Method
- DB22/T 1985-2013 Determination of Inorganic Arsenic in Feed by Liquid Chromatography-Atomic Fluorescence Spectrometry
National Metrological Verification Regulations of the People's Republic of China
- JJG 1151-2018 Liquid Chromatograph-Atomic Fluorescence Spectrometers
国家市场监督管理总局、中国国家标准化管理委员会
- GB/T 40900-2021 Determination of fluorescent brightener 367 and fluorescent brightener 393 in cosmetics—Liquid chromatography-tandem mass spectrometry
Shandong Provincial Standard of the People's Republic of China
- DB37/T 4090-2020 Determination of Inorganic Arsenic in Cosmetics by Liquid Chromatography-Atomic Fluorescence Spectrometry
国家质量监督检验检疫总局
- SN/T 4947-2017 Determination of five fluorescent bleachers in detergents-High performance liquid chromatography
Professional Standard - Agriculture
- GB/T 44147-2024 The method of performance testing for liquid chromatography coupled atomic fluorescence spectrometer
Sichuan Provincial Standard of the People's Republic of China
- DB51/T 1699-2013 Determination of total sulfur content in liquefied petroleum gas (LPG) by ultraviolet fluorescence method
- DB51/T 1689-2013 Determination of total sulfur content in liquefied natural gas (LNG) by ultraviolet fluorescence method
农业农村部
- NY/T 3870-2021 Determination of selenoamino acid in selenoprotein—Liquid chromatography-atomic fluorescence spectrometry
Jiangxi Provincial Standard of the People's Republic of China
- DB36/T 1904-2023 Fluorescent quantitative PCR detection method for Mycoplasma in experimental animals
Professional Standard - Electron
- SJ/T 11397-2009 Phosphors for light emitting diodes
未注明发布机构
- DIN EN ISO 17993 E:2003-06 Determination of 15 polycyclic aromatic hydrocarbons in water using high performance liquid chromatography and fluorescence detection after liquid-liquid extraction (draft)
Taiwan Provincial Standard of the People's Republic of China
- CNS 927-2006 Ballasts for fluorescent lamp
Xinjiang Provincial Standard of the People's Republic of China
- DB65/T 4367-2021 Water Quality Determination of Methylmercury and Ethylmercury by Liquid Chromatography-Atomic Fluorescence Spectrometry
SCC
- AWWA ACE94191 Monitoring to Identify Causative Factors of Degradation of Water Quality: What to Look For
- DIN EN 17178 E:2018 Draft Document - Liquid petroleum products - Determination of the total volatile sulfur content in liquefied petroleum gases by ultraviolet fluorescence spectroscopy; German and English version prEN 17178:2018
- NS-EN 17178:2019 Liquid petroleum products — Determination of the total volatile sulfur content in liquefied petroleum gases by ultraviolet fluorescence spectroscopy
- DANSK DS/EN 17178:2019 Liquid petroleum products – Determination of the total volatile sulfur content in liquefied petroleum gases by ultraviolet fluorescence spectroscopy
- AWWA IMTECH54035 Application Service Providers (ASPs): What Are They, and How Do They Fit Into Your Overall IT Strategy?
- NS-EN 16997:2017 Liquid petroleum products — Determination of the sulfur content in Ethanol (E85) automotive fuel- Wavelength dispersive X-ray fluorescence spectrometric method
- AENOR UNE-EN 16997:2017 Liquid petroleum products. Determination of sulfur content in ethanol automotive fuel (E85). Wavelength-dispersive X-ray fluorescence spectrometry method.
- DANSK DS/ISO 22940:2021 Solid recovered fuels – Determination of elemental composition by X-ray fluorescence
- NS-EN ISO 17993:2003 Water quality — Determination of 15 polycyclic aromatic hydrocarbons (PAH) in water by HPLC with fluorescence detection after liquid-liquid extraction (ISO 17993:2002)
- AENOR UNE-EN ISO 17993:2004 Water quality - Determination of 15 polycyclic aromatic hydrocarbons (PAH) in water by HPLC with fluorescence detection after liquid-liquid extraction (ISO 17993:2002)
- 10/30199746 DC BS EN 16162. Animal feeding stuffs. Determination of Decoquinate by HPLC with fluorescence detection
- DANSK DS/EN 62703:2013 Expression of performance of fluorometric oxygen analyzers in liquid media
- CEI EN 62703:2014 Expression of performance of fluorometric oxygen analyzers in liquid media
- DANSK DS/EN ISO 17993:2004 Water quality - Determination of 15 polycyclic aromatic hydrocarbons (PAH) in water by HPLC with fluorescence detection after liquid-liquid extraction
Korean Agency for Technology and Standards (KATS)
- KS M ISO 3837:2003 Liquid petroleum products-Determination of hydrocarbon types-Fluorescent indicator adsorption method
- KS A 0084-2015 Methods of measurement for colour of fluorescent objects
- KS A 0084-2006 Methods of measurement for colour of fluorescent objects
- KS M ISO 3837-2003(2018) Liquefied petroleum products - Hydrocarbon content test method - Fluorescent indicator adsorption method
- KS A 3861-2020 Method for Determining Fluorographic of Sensitivity Photographic Sensitive Materials Used with Green Fluorescent Screen
- KS A 3601-2015(2020) Light source for determining fluorographic sensitivity of photegraphic sensitive materials used with green fluorescent screen
- KS A 3861-2015 Method for Determining Fluorographic of Sensitivity Photographic Sensitive Materials Used with Green Fluorescent Screen
- KS M ISO 14597:2003 Petroleum products-Determination of vanadium and nickel content-Wavelength-dispersive X-ray fluorescence spectrometry
- KS A 3861-2015(2020) Method for Determining Fluorographic of Sensitivity Photographic Sensitive Materials Used with Green Fluorescent Screen
- KS C 7605-1967 Photometric measurement on standard fluorescent lamps
- KS I ISO 17993:2022 Water quality — Determination of 15 polycyclic aromatic hydrocarbons — PAH in water by HPLC with fluorescence detection after liquid-liquid extraction
- KS I ISO 17993-2008(2013) Water quality-Determination of 15 polycyclic aromatic hydrocarbons(PAH) in water by HPLC with fluorescence detection after liquid-liquid extraction
- KS I ISO 7981-2:2006 Water quality-Determination of polycyclic aromatic hydrocarbons (PAH)-Part 2:Determination of six PAH by high-performance liquid chromatography with fluorescence detection after liquid-liquid extraction
- KS I ISO 21458-2011(2016) Water quality - Determination of glyphosate and AMPA - Method using high performance liquid chromatography(HPLC) and fluorometric detection
- KS I ISO 7981-2:2014 Water quality-Determination of polycyclic aromatic hydrocarbons (PAH)-Part 2:Determination of six PAH by high-performance liquid chromatography with fluorescence detection after liquid-liquid extraction
BR-ABNT
- ABNT NBR 14932-2011 Liquid petroleum products - Determination of hydrocarbon types by fluorescent indicator adsorption
British Standards Institution (BSI)
- BS ISO 17993:2002 Water quality - Determination of 15 polycyclic aromatic hydrocarbons (PAH) in water by HPLC with fluorescence detection after liquid-liquid extraction
- BS EN 17178:2019 Liquid petroleum products. Determination of the total volatile sulfur content in liquefied petroleum gases by ultraviolet fluorescence spectroscopy
- BS EN 13506:2002*BS 6068-2.74:2002 Water quality - Determination of mercury by atomic fluorescence spectrometry
- BS EN 13506:2002 Water quality - Determination of mercury by atomic fluorescence spectrometry
- BS ISO 7981-2:2005 Water quality - Determination of polycyclic aromatic hydrocarbons (PAH) - Determination of six PAH by high-performance liquid chromatography with fluorescence detection after liquid-liquid extraction
- BS EN ISO 17993:2002 Water quality - Determination of 15 polycyclic aromatic hydrocarbons (PAH) in water by HPLC with fluorescence detection after liquid-liquid extraction
- BS 3680-2D:1993 Measurement of liquid flow in open channels. Dilution methods. Methods of measurement using fluorescent tracers
- BS ISO 7981-1:2005 Water quality - Determination of polycyclic aromatic hydrocarbons (PAH) - Determination of six PAH by high performance thin layer chromatography with fluorescence detection after liquid-liquid extraction
- BS EN 16162:2012 Animal feeding stuffs. Determination of decoquinate by HPLC with fluorescence detection
International Organization for Standardization (ISO)
- ISO 3837:1993 Liquid petroleum products; determination of hydrocarbon types; fluorescent indicator adsorption method
- ISO 3837:1993/Amd 1:2021 Liquid petroleum products - Determination of hydrocarbon types - Fluorescent indicator adsorption method; Amendment 1
- ISO 3837:1993/Cor 1:1994 Liquid petroleum products - Determination of hydrocarbon types - Fluorescent indicator adsorption method; Technical Corrigendum 1
- ISO 3837:1993/Cor 2:1996 Liquid petroleum products — Determination of hydrocarbon types — Fluorescent indicator adsorption method — Technical Corrigendum 2
- ISO 4883:1978 Hardmetals; Determination of contents of metallic elements by X-ray fluorescence; Solution method
- ISO 7981-2:2005 Water quality - Determination of polycyclic aromatic hydrocarbons (PAH) - Part 2: Determination of six PAH by high-performance liquid chromatography with fluorescence detection after liquid-liquid extraction
YU-JUS
- JUS B.H8.063-1991 Liquid petroleum,products - Determination of hydrocarbon types - Fluorescent indicator adsorption
- JUS H.B8.196-1980 Aluminium fluoride for industrial use. Determination ofsulphur content. X-ray fluorescence method
Association Francaise de Normalisation
- NF EN 17178:2019 Liquid petroleum products - Determination of volatile sulfur content in liquefied petroleum gases by ultraviolet fluorescence spectroscopy
- NF M07-024:1969 Liquid fuels. Determination of hydrocarbon groups in liquid petroleum products. Adsorption method in presence of fluorescent indicators.
- NF EN 16997:2017 Liquid petroleum products - Determination of sulfur content in ethanol fuel for automobiles (E85) - Wavelength dispersive X-ray fluorescence spectrometric method
- NF X34-233*NF EN ISO 22940:2021 Solid recovered fuels - Determination of elemental composition by X-ray fluorescence
- NF EN 16162:2012 Aliments des animaux - Dosage du décoquinate par chromatographie liquide à haute performance (CLHP) avec détection par fluorescence
- NF M41-027*NF EN 17178:2019 Liquid petroleum products - Determination of the total volatile sulfur content in liquefied petroleum gases by ultraviolet fluorescence spectroscopy
- NF A24-003:1985 Chemical analysis of zinc ores concentrates. Accurate determination of zinc samples by X-ray fluorescence spectrometry on sample solution containing an internal standard.
- NF T90-115:2004 Water quality - Determination of 15 polycyclic aromatic hydrocarbons (PAH) in water by HPLC with fluorescence detection after liquid-liquid extraction.
- NF EN 24883:1993 Hard metals - Determination of metallic elements by X-ray fluorescence - Solution method
RU-GOST R
- GOST R 52063-2003 Liquid petroleum products. Test method of hydrocarbon types by fluorescent indicator adsorption
- GOST R 55992.1-2014 In vitro diagnostic medical devices for fluorescent and immunofluorescent analysis of ?dried spot? of newborn's blood. Part 1. Instruments and accessories for fluorescent and immunofluorescent analysis of ?dried spot? of newborn's blood. Technical require
- GOST R 55992.2-2014 In vitro diagnostic medical devices for fluorescent and immunofluorescent analysis of ?dried spot? of newborn's blood. Part 2. Sonsumables (kits of reagents) for fluorescent and immunofluorescent analysis of ?dried spot? of newborn's blood. Technical requ
- GOST R 56866-2016 Gaseous hydrocarbons and liquefied petroleum gases. Determination of total volatile sulfur by method of ultraviolet fluorescence
American Society for Testing and Materials (ASTM)
- ASTM D3278-82e1 Standard Test Methods for Flash Point of Liquids by Setaflash Closed-Cup Apparatus
- ASTM E1209-18 Standard Practice for Fluorescent Liquid Penetrant Testing Using the Water-Washable Process
- ASTM C1343-96(2007) Standard Test Method for Determination of Low Concentrations of Uranium in Oils and Organic Liquids by X-ray Fluorescence
- ASTM E1208-16 Standard Practice for Fluorescent Liquid Penetrant Testing Using the Lipophilic Post-Emulsification Process
- ASTM D1319-13 Standard Test Method for Hydrocarbon Types in Liquid Petroleum Products by Fluorescent Indicator Adsorption
- ASTM UOP1013-16 Total Chloride in Liquid Hydrocarbons by Wavelength Dispersive X-Ray Flourescence
- ASTM D1319-10 Standard Test Method for Hydrocarbon Types in Liquid Petroleum Products by Fluorescent Indicator Adsorption
- ASTM E1219-16 Standard Practice for Fluorescent Liquid Penetrant Testing Using the Solvent-Removable Process
German Institute for Standardization
- DIN EN 17178:2018 Liquid petroleum products - Determination of the total volatile sulfur content in liquefied petroleum gases by ultraviolet fluorescence spectroscopy; German and English version prEN 17178:2018
- DIN EN 17178:2019-12 Liquid petroleum products - Determination of the total volatile sulfur content in liquefied petroleum gases by ultraviolet fluorescence spectroscopy; German version EN 17178:2019
- DIN EN 16997:2017-10 Liquid petroleum products - Determination of the sulfur content in Ethanol (E85) automotive fuel - Wavelength dispersive X-ray fluorescence spectrometric method; German version EN 16997:2017
- DIN EN ISO 17993:2004 Water quality - Determination of 15 polycyclic aromatic hydrocarbons (PAH) in water by HPLC with fluorescence detection after liquid-liquid extraction (ISO 17993:2002); German version EN ISO 17993:2003
- DIN EN ISO 17993:2004-03 Water quality - Determination of 15 polycyclic aromatic hydrocarbons (PAH) in water by HPLC with fluorescence detection after liquid-liquid extraction (ISO 17993:2002); German version EN ISO 17993:2003
- DIN EN 17178:2019 Liquid petroleum products - Determination of the total volatile sulfur content in liquefied petroleum gases by ultraviolet fluorescence spectroscopy
ES-UNE
- UNE-EN 17178:2020 Liquid petroleum products - Determination of the total volatile sulfur content in liquefied petroleum gases by ultraviolet fluorescence spectroscopy
GSO
- GSO ISO 3837:2009 Liquid petroleum products - Determination of hydrocarbon types - Fluorescent indicator adsorption method
- OS GSO ISO 3837:2009 Liquid petroleum products - Determination of hydrocarbon types - Fluorescent indicator adsorption method
- OS GSO IEC 62703:2017 Expression of performance of fluorometric oxygen analyzers in liquid media
- GSO IEC 62703:2017 Expression of performance of fluorometric oxygen analyzers in liquid media
- GSO ISO 9555-4:2014 Measurement of liquid flow in open channels -- Tracer dilution methods for the measurement of steady flow -- Part 4: Fluorescent tracers
GOST
- GOST R 52063-2023 Liquid petroleum products. Determination of hydrocarbon types by fluorescent indicator adsorption method
- GOST ISO 17993-2016 Water quality Determination of 15 polycyclic aromatic hydrocarbons (PAHs) High performance liquid chromatography method with fluorescence detection after liquid-liquid extraction
PL-PKN
- PN-EN 17178-2020-01 P Liquid petroleum products--Determination of the total volatile sulfur content in liquefied petroleum gases by ultraviolet fluorescence spectroscopy
GOSTR
- GOST ISO 20846-2016 Liquid petroleum products. Determination of sulfur content of automotive fuels. Ultraviolet fluorescence method
- GOST 34049-2017 Milk and milk products. Determination of aflatoxin M1 by high-performance liquid chromatography with fluorimetric (spectrofluorometric) detection
- GOST ISO 20884-2016 Liquid petroleum products. Determination of sulfur content of automotive fuels. Wavelength-dispersive X-ray fluorescence spectrometry
US-CFR-file
- CFR 1-51.9-2014 General provisions. Part51:Incorporation by reference. Section51.9:What is the proper language of incorporation?
- CFR 1-51.3-2014 General provisions. Part51:Incorporation by reference. Section51.3:When will the Director approve a publication?
- CFR 40-60.5430-2013 Protection of Environment. Part60:Standards of performance for new stationary sources. Section60.5430:What definitions apply to this subpart?
- CFR 1-51.7-2014 General provisions. Part51:Incorporation by reference. Section51.7:What publications are eligible?
- CFR 43-3000.12-2014 Public Lands:Interior. Part3000:Minerals management: General. Section3000.12:What is the fee schedule for fixed fees?
KR-KS
- KS M ISO 3837-2023 Liquid petroleum products — Determination of hydrocarbon types — Fluorescent indicator adsorption method
- KS I ISO 17993-2022 Water quality — Determination of 15 polycyclic aromatic hydrocarbons — PAH in water by HPLC with fluorescence detection after liquid-liquid extraction
Japanese Industrial Standards Committee (JISC)
- JIS K 7606:1976 Light source for determining fluorographic sensitivity of photographic sensitive materials used with green fluorescent screen
- JIS K 7607:1976 Method for determining fluorographic sensitivity of photographic sensitive materials used with green fluorescent screen
- JIS Z 8717:1989 Methods of measurement for colour of fluorescent objects
Danish Standards Foundation
- DS/EN 24883:1993 Hardmetals. Determination of contents of metallic elements by X-ray fluorescence. Solution method
- DS/ISO 22940:2021 Solid recovered fuels – Determination of elemental composition by X-ray fluorescence
- DS/EN ISO 17993:2004 Water quality - Determination of 15 polycyclic aromatic hydrocarbons (PAH) in water by HPLC with fluorescence detection after liquid-liquid extraction
- DS/EN 62703:2013 Expression of performance of fluorometric oxygen analyzers in liquid media
- DS/ISO 4883:1994 Hardmetals - Determination of contents of metallic elements by x-ray fluorescence - Solution method
- DS/IEC 458:1981 Transistorized ballasts for tubular fluorescent lamps
- DS/EN 24883:1994 Hardmetals - Determination of contents of metallic elements by x-ray fluorescence - Solution method
- DS/EN 16162:2012 Animal feeding stuffs - Determination of decoquinate by HPLC with fluorescence detection
AT-ON
- OENORM EN 17600-2020 Paper and board intended to come into contact with foodstuffs - Determination of the fastness of fluorescent whitened paper and board - Analysis by high-performance liquid chromatography with fluorescence detection
European Committee for Standardization (CEN)
- EN ISO 17993:2003 Water quality Determination of 15 polycyclic aromatic hydrocarbons (PAH) in water by HPLC with fluorescence detection after liquid-liquid extraction
- EN 16162:2012 Animal feeding stuffs - Determination of decoquinate by HPLC with fluorescence detection
- HD 302 S1-1977 Transistorized ballast for fluorescent lamps
AENOR
- UNE-EN ISO 17993:2004 Water quality - Determination of 15 polycyclic aromatic hydrocarbons (PAH) in water by HPLC with fluorescence detection after liquid-liquid extraction (ISO 17993:2002)
- UNE 81594:1992 BIOLOGICAL CONTROL. DETERMINATIO OF ZINC PROTOPORPHYRIN (ZPP) IN BLOOD. METHOD OF DIRECT READING (HEMATOFLUOROMETER).
- UNE-EN 16162:2012 Animal feeding stuffs - Determination of decoquinate by HPLC with fluorescence detection
- UNE-EN 16997:2017 Liquid petroleum products - Determination of the sulfur content in Ethanol (E85) automotive fuel- Wavelength dispersive X-ray fluorescence spectrometric method
Lithuanian Standards Office
- LST EN ISO 17993:2004 Water quality - Determination of 15 polycyclic aromatic hydrocarbons (PAH) in water by HPLC with fluorescence detection after liquid-liquid extraction (ISO 17993:2002)
International Electrotechnical Commission (IEC)
- IEC 62703:2013 Expression of performance of fluorometric oxygen analyzers in liquid media
European Committee for Electrotechnical Standardization(CENELEC)
- EN 62703:2013 Expression of performance of fluorometric oxygen analyzers in liquid media
CEN - European Committee for Standardization
- PREN 17178-2018 Liquid petroleum products - Determination of the total volatile sulfur content in liquefied petroleum gases by ultraviolet fluorescence spectroscopy