Acetic acid rotation

Acetic acid rotation, Total:178 items.

The international standard classification for "Acetic acid rotation" includes: Organic acids , Water quality in general , Workplace atmospheres , Ambient atmospheres , Metalliferous minerals , Water quality , Acids , Essential oils , Manganese ores , Chemical reagents , Soil quality. Pedology , Water of natural resources , Wastes in general , Chemical analysis , Non-metalliferous minerals .

The Chinese standard classification for "Acetic acid rotation" includes: General organic chemicals , Analysis methods for toxic substances in atmosphere , Labor sanitation , Manganese ore , Analysis methods for toxic substances in water , Inorganic acid and alkali , Fragrances and flavors , Chemical reagent in general , Analysis methods for environmental quality of soils , Steel and iron alloy analysis method , Diagnostic standard for occupational diseases , Basic standards and general methods , Analysis methods for exhaust emission pollutants , Environmental pollutant monitoring methods , Environmental sanitation , Sampling methods for solid waste, soil and other environmental elements , Basic standards and general methods , Basic standards and general methods for synthetic resin and plastic , Special electronic technology material , Metallurgical auxiliary material ore , Hydrogeological survey .

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

GB/T 12374-1990 Standard method for examination of nitrate in air of residential areas--Reduction of the cadmium column-spectrophotometry of N-(1-naphthyl)ethylene diamine hydrochloride
GB/T 11198.5-1989 Sulphuric acid for industrial use--Determination of arsenic content--Silver diethyldithiocarbamate photometric method
GB/T 613-2007 Chemical reagent - General method for the determination of specific optical rotatory power (specific optical rotation)
GB/T 7474-1987 Water quality--Determination of copper--Sodium diethyldithiocarbamate spectrophotometric method
GB/T 16114-1995 Workplace air―Determination of chloronitrobenzene―N-(1-naphthyl)-ethylenediamine dihydrochloride spectrophotometric method
GB/T 15504-1995 Water quality－Determination of carbon disulfide－Diethylamine cupric acetate spectrophotometric method
GB/T 15502-1995 Air quality －Determination of aniline －N-(1-naphthyl) ethylene diamine dihydrochloride spectrophotometric method
GB/T 16035-1995 Workplace air--Determination of arsine--Silver diethyl dithiocarbamate spectrophotometric method
GB/T 1628.2-2000 Glacial acetic acid for industrial use-Determination of acetic acid content-Titrimetric method
GB/T 16102-1995 Workplace air--Determination of nitrobenzene--Naphthyl ethylenediamine dihydrochloride spectrophotometric method
GB/T 13580.7-1992 Determination of nitrite in the wet precipitation.N-(1-naphthyl)-1,2-diaminoethane dihydrochloride spectrophotometry
GB/T 29848-2018(英文版) Ethylene vinyl acetate copolymer (EVA) film for PV module
GB/T 7485-1987 Water quality - Determination of total arsenic - Silver diethyldithiocarbamate spectrophotometric method
GB/T 14454.5-2008 Fragrance/Flavor substances - Determination of optical rotation
GB/T 16032-1995 Workplace air--Determination of nitrogen oxides--Naphthyl ethylenediamine dihydrochloride spectrophotometric method
GB/T 16115-1995 Workplace air―Determination of chorodinitrobenzene―N-(1-naphthyl)-ethylenediamine dihydrochloride spectrophotometric method
GB/T 223.27-1994 Methods for chemical analysis of iron,steel and alloy The thiocyanate-butyl acetate extraction spectrophotometric method for the determination of molybdenum content
GB/T 14454.5-1993 Aromatics. Determination of optical rotation
GB 7474-1987 Water quality; Determination of copper; Sodium diethyldithiocarbamate spectrophotometric method
GB/T 16101-1995 Workplace air―Determination of chloropicrin―Naphthyl ethylenediamine dihydrochloride spectrophotometric method
GB/T 16100-1995 Workplace air--Determination of aniline--Naphthyl ethylenediamine dihydrochloride spectrophotometric method
GB/T 6276.7-1986 Ammonium hydrogen carbonate for industrial use--Determination of arsenic content--Silver diethyl dithiocarbamate photometric method
GB/T 1516-1979 Method for determination of arsenic content in manganese ores
GB/T 17134-1997 Soil quality-Determination of total arsenic-Silver diethyldithiocarbamate spectrophotometry
GB/T 1516-2006 Manganese ores - Determination of arsenic content - Silver diethyldithiocarbamate spectrophotometric method
GB 223.27-1984 Methods for chemical analysis of iron, steel and alloy--The thiocyanate-butyl acetate extraction photometric method for the determination of molybdenum content
GB/T 16119-1995 Workplace air－Determination of Rogor―N-(1-naphthyl)-ethylenediamine- hydrochloride spectrophotometric method
GB/T 15555.3-1995 Solid waste - Determination of arsenic - Silver diethyldithiocarbamate spectrophotometric method

Professional Standard - Hygiene

WS/T 64-1996 Urine - Determination of trichloroacetic acid - Spectrophotometric method
WS/T 28-1996 Urine - Determination of arsenic - Silver diethyldithiocarbamate - Triethanolamine - Spectrophotometric method
WS/T 23-1996 Urine—Determination of δ-aminolevulinic acid—Spectrophotometric method
WS/T 168-1999 Workplace air.Determination of diphenyl methane 4,4'-di-iso-cyanate-N-(1-naphthyl) ethylenediamine dihydrochloride spectrophotometric method

Group Standards of the People's Republic of China

T/CASME 720-2023 O-Acetyl-L-carnitine hydrochloride
T/JSQA 105-2021 Ethylene-vinyl acetate resin for photovoltaic film
T/ZZB 0682-2018 Acetyl L-carnitine hydrochlorate

国家质量监督检验检疫总局

SN/T 0859-2016 Determination of dehydroacetic acid in condiments for export- Ultraviolet spectrophotometric method

Professional Standard - Environmental Protection

HJ 667-2013 Water quality-Determination of total nitrogen by continuous flow analysis(CFA) and N-(1-naphthyl)ethylene diamine dihydrochloride
HJ 540-2009 Ambient air and waste gas - Determination of arsenic - Silver diethyldithiocarbamate spectrophotometric method
HJ/T 43-1999 Stationary source emission -- Determination of nitrogen oxid -- N(1-naphtye) -- Ethylenediamine dihydrochloride spectrophotometric method
HJ 485-2009 Water quality - Determination of copper - Sodium diethydlthiocabamate spectrophotometric method
HJ 668-2013 Water quality-Determination of total nitrogen by flow injection analysis（FIA）and N-(1-naphthyl)ethylene diamine dihydrochloride spectrophotometry
HJ 540-2016 Stationary source emission - Determination of arsenic -Silver diethyldithiocarbamate spectrophotometric method

Professional Standard - Petrochemical Industry

SH/T 1628.4-1996 Determination for acidity of industrial vinyl acetate - Titration method

中华人民共和国环境保护部

GB 7485-1987 Water quality-Determination of total arsenic-Silver diethyldithiocarbamate spectrophotometric method
GB 13580.7-1992 Determination of nitrite in the wet precipitation - N-(1-naphthyl)-1, 2-diaminoethane dihydrochloride spectrophotometry

中华人民共和国国家卫生和计划生育委员会

GB 12374-1990 standard method for examination of nitrate in air of residential areas-Reduction of the cadmium column-the spectrophotometry of N-(1-naphthyl)ethylenediaminl hydrochloride

Taiwan Provincial Standard of the People's Republic of China

CNS 6574-2006 Essential oils - Determination of optical rotation
CNS 6574-1980 Determination of the Optical Rotation of Essential Oils
CNS 8837-1996 Methods of Test for Optical Rotation of Chemical Products
CNS 13318-1993 General Method for the Determination of Arsenic - Sliver Diethyldithiocarbamate Photometric Method

Professional Standard - Light Industry

QB 975-1984 Essential oils - Determination of optical rotation

Professional Standard - Urban Construction

CJ/T 102-1999 Municipal domestic refuse―Determination of arsenic―Spectrophotometric method with silver diethyldithiocarbamate
CJ/T 66-1999 Municipal sewage.Determination of copper.Sodium diethyldithiocabamate spectrophotometric method
CJ/T 73-1999 Municipal sewage.Determination of total arsenic.Silver diethyldithiocarbamate spectrophotometric method

Shanxi Provincial Standard of the People's Republic of China

DB14/T 1606-2018 Sodium Acetate-Flame Photometric Rapid Determination of Soil Cation Exchange Capacity

Professional Standard - Commodity Inspection

SN/T 2946-2011 Determination of the Vinyl Acetate Content of Ethylene-vinyl Acetate Copolymers - Fourier Transform Infrared Spectroscopy

Professional Standard - Chemical Industry

HG/T 4548-2013 Determination of Arsenic in Waste Chemicals - Silver Diethyldithiocarbamate Spectrophotometric Method
HG/T 2752-1996 Determination of Free Acidity of Non-plasticised Cellulose Acetate

国家市场监督管理总局、中国国家标准化管理委员会

GB/T 36965-2018 Test method for cross-linking degree of ethylene-vinyl acetate copolymer applied in photovoltaic modules. Differential scanning calorimetry(DSC)
GB/T 5195.19-2018 Fluorspar—Determination of arsenic content—Silver diethyldithiocarbamate spectrometric method

Professional Standard - Agriculture

2316药典二部-2010 Appendix VI E Optical Polarimetry
1774药典一部-2010 Appendix VII E Optical polarimetry

Professional Standard - Geology

DZ/T 0064.10-1993 Groundwater quality test methods - the determination of arsenicum in silver diethyl dithiocarbamate spectrophotometric method

Professional Standard - Non-ferrous Metal

YS/T 74.5-1994 Methods for chemical analysis of cadmium-lead diethyldithiocarbamate spectrophotometric method for the determination of copper

BELST

STB GOST R 51441-2007 Fruit and vegetable juices. Enzymatic method for spectrophotometric determination of acetic (acetate) content

British Standards Institution (BSI)

BS EN 12632:1999 Fruit and vegetable juices. Enzymatic determination of acetic acid (acetate) content. NAD spectrometric method
BS EN 26595:1993(2008)*BS 6068-2.1:1993*ISO 6695:1982 Water quality — Determination of total arsenic — Silver diethyldithiocarbamate spectrophotometric method
BS ISO 592:1998(2001) Essential oils — Determination of optical rotation
BS EN 26595:1983 Water quality - Determination of total arsenic - Silver diethyldithiocarbamate spectrophotometric method
BS ISO 592:1998 Essential oils - Determination of optical rotation
BS ISO 592:2001 Essential oils - Determination of optical rotation

YU-JUS

JUS H.B8.215-1984 Acetic acid for industrial use. Determination ofcopper contsnt. Photomatric method
JUS H.G8.398-1989 Reagents. Nitric acid. Determination of arsenic content. Silver diethvldithiocarbanate spectrophotometric method
JUS H.B8.219-1984 Acetic acid for industrial use. Determination of arsenic content. Silver diethyldithiocarbamate photo- metric method
JUS H.G8.462-1991 Reagents.Potassium sulphate.Determination of arsenic content.Silver diethyldithiocarbamate spectrophotometric method
JUS H.G8.359-1988 Reagents. (+)-Tartaric acid. ?etermination of arsenic content. Silver dlethjrl- dithiocarbamate spectrophotometric method
JUS H.G8.477-1991 Reagents. Orthophosphoric aci?. Determination of arsenic content. Silver diethvldithiocarbamate spectrophotoraetric method
JUS H.G8.073-1983 Reagents. Borje acid. Determination of arsenic content. Silver diethyldithiocarbamate photometric method
JUS H.G8.491-1991 Reagents. Potassium permanganate. Determination of arsenic content. Silver diethyldithiocarbamate spectrophotometric method
JUS H.G8.018-1980 Reagents. Hydrochloric acid. Determination of arsenic content. Silver diethyldithiocarbonate photome- tric method
JUS H.G8.033-1981 Reagents. Sulphuric acid. Determination of arsenic content Silver diethyldithiocarbamate photometric method
JUS H.G8.148-1985 Reagents.Ammonium sulphate. Determination of arsenic content Silver diethyldlthiocarbamate photo- metric method
JUS H.B8.356-1982 Boric acid for industrial use. Detenmination of arsenic content Silver diethyldithiocartwnate photometric method
JUS H.B8.208-1984 Acetic acid for industrial use. Determination of iron content 1,10-Phenanthroline photometric method
JUS H.G8.164-1984 Reagents. Sodium carbonate anhydrous and sodium carbonate decahydrate. Determination of arsenic content. Si Iver diethyldithiocarbamate photometric method
JUS H.G8.121-1984 Reagents. Citric acid monohydrate. Determination of arsen/c content. Silver diethyldithiocarbamate photometric method
JUS H.G8.450-1990 Reagents. Zine sulphate heptahydrate- Determination of arsenic content. Silver diethvldithiocarbamate speetrophotometric method
JUS H.B8.212-1984 Acetic acid for industrial use. Measurement ofcolor in Hazen units. Colorimetric method

CZ-CSN

CSN 66 1252-1985 Determination of acidity as acetic actd
CSN ISO 777:1993 Pulps. Determination of calcium content - edta tirimetric and flame atomic absorption spectrometric methods
CSN 68 4075-1983 Met hod for determination of specific otatien
CSN ISO 5959:1992 Copper and copper alloys - Determination of bismuth content - Diethyldithiocarbamate spectrometric method

American Society for Testing and Materials (ASTM)

ASTM D2086-99 Standard Test Method for Acidity in Vinyl Acetate and Acetaldehyde
ASTM D2086-03 Standard Test Method for Acidity in Vinyl Acetate and Acetaldehyde
ASTM D2086-08(2012) Standard Test Method for Acidity in Vinyl Acetate and Acetaldehyde
ASTM D2086-02 Standard Test Method for Acidity in Vinyl Acetate and Acetaldehyde
ASTM D2086-08 Standard Test Method for Acidity in Vinyl Acetate and Acetaldehyde
ASTM D2086-22 Standard Test Method for Acidity in Vinyl Acetate and Acetaldehyde
ASTM D8496-23 Standard Test Method for Determination of Hydroquinone (HQ) Content in Vinyl Acetate Monomer (VAM) Using Ultraviolet-Visible (UV-Vis) Spectrophotometer
ASTM D5629-05 Standard Test Method for Polyurethane Raw Materials Determination of Acidity in Low-Acidity Aromatic Isocyanates and Polyurethane Prepolymers

Association Francaise de Normalisation

NF T20-273:1982 Hydrochloric acid for industrial use. Determination of arsenic content. Silver diethyldithiocarbamate photometric method.
NF T20-298:1982 Sulphuric acid for industrial use. Determination of arsenic content. Silver diethyldithiocarbamate photometric method.
NF T12-023:1982 Cellulose. Determination of the calcium content. Edta titrimetric method and flame atomic absorption spectrometric method.
NF T90-026:1993 Water quality - Determination of total arsenic - Silver diethyldithiocarbamate spectrophotometric method.
NF ISO 592:1999 Huiles essentielles - Détermination du pouvoir rotatoire
NF ISO 5959:1986 Copper and copper alloy - Determination of bismuth - Diethyldithiocarbamate spectrometric method
NF T60-369:1980 Glycerines for industrial use. Determination of arsenic content. Silver diethldithiocarbamate photometric method.
NF T20-497:1979 Condensed phosphates for industrial use (including foodstuffs). Determination of arsenic content. Silver diethyldithiocarbamate photometric method.
NF T52-136:1979 Plastics. Basic materials for polyurethanes. Toluylenediisocyanate. Determination of acidity.

IN-BIS

IS 12179-1987 Chemical cotton sulfuric acid photometry and in-bottle acetylation determination method
IS 8661-1977 Specifications for polarimeters and sugar meters (optical)

Korean Agency for Technology and Standards (KATS)

KS M 9143-2002 WATER QUALITY-DETERMINATION OF TOTAL ARSENIC-SILVER DIETHYLDITHIOCARBAMATE SPECTROPHOTOMETRIC METHOD
KS H ISO 592-2014(2019) Essential oils — Determination of optical rotation
KS M 9143-2005 WATER QUALITY-DETERMINATION OF TOTAL ARSENIC-SILVER DIETHYLDITHIOCARBAMATE SPECTROPHOTOMETRIC METHOD
KS M 0006-2010 Test methods for optical rotation of chemical products
KS H ISO 592-2019 Essential oils — Determination of optical rotation
KS H ISO 592:2014 Essential oils — Determination of optical rotation
KS H ISO 592:2006 Essential oils-Determination of optical rotation
KS M ISO 2590-2019 General method for the determination of arsenic－Silver diethyldithiocarbamate photometric method
KS M ISO 2590-2004(2014) General method for the determination of arsenic－Silver diethyldithiocarbamate photometric method
KS M 5958-1994 Quick-Drying styrenated alkyd type lusterless enamel

SCC

DANSK DS/EN 15487:2007 Ethanol as a blending component for petrol - Determination of phosphorus content - Ammonium molybdate spectrometric method
NS-EN 15487:2007 Ethanol as a blending component for petrol — Determination of phosphorus content — Ammonium molybdate spectrometric method
NS-ISO 6595:1982 Water quality — Determination of total arsenic — Silver diethyldithiocarbamate spectrophotometric method
DANSK DS/ISO 2590:1981 General method for the determination of arsenic – Silver diethyldithiocarbamate photometric method
NS-EN 26595:1992 Water quality — Determination of total arsenic — Silver diethyldithiocarbamate spectrophotometric method (ISO 6595:1982)
UNE-EN 26595:1994 WATER QUALITY. DETERMINATION OF TOTAL ARSENIC. SILVER DIETHYLDITHIOCARBAMATE SPECTROPHOTOMETRIC METHOD. (ISO 6595:1982).
AS 2508.3.002:1982 Safe storage and handling information card - Acetates (ethyl acetate, propyl acetates, butyl acetates, amyl acetate)
NS 9007:1981 General method for the determination of arsenic — Silver diethyldithiocarbamate photometric method

Danish Standards Foundation

DS/EN 26595:1993 Water quality. Determination of total arsenic. Silver diethyldithiocarbamate spectrophotometric method
DS/ISO 2590:1981 General method for the determination of arsenic. Silver diethyldithiocarbamate photometric method

TR-TSE

TS 2842-1977 SULPHUR FOR INDUSTRIAL USE DETERMINATION OF ARSENIC CONTENT - SILVER DIETHYLDITHIOCARBAMATE PHOTOMETRIC METHOD
TS 3581-1981 METHODS FOR THE ANALYSIS OF WATER DETERMINATION OF THE ARSENIC CONTENT SILVER DIETHYLDITHIOCARBAMATE SPECTROPHOTOMETRY METHOD

GSO

GSO ISO 592:2015 Essential oils -- Determination of optical rotation
BH GSO ISO 592:2016 Essential oils -- Determination of optical rotation
GSO ISO 2590:1997 General method for the determination of arsenic- silver diethylchthio - carbamate photometric method.
OS GSO ISO 5959:2013 Copper and copper alloys -- Determination of bismuth content -- Diethyldithiocarbamate spectrometric method

RU-GOST R

GOST R 53125-2008 Honey. Method for determination of optical activity
GOST 30621-1998 Hydrochloric acid for industrial use. Determination of arsenic content by silver diethyldithiocarbamate photometric method
GOST 31773-2012 Honey. Method for determination of optical activity
GOST 30355.5-1996 Sulphur for industrial use. Determination of arsenic content. Silver diethyldithiocarbamate photometric method
GOST ISO 592-2014 Essential oils. Method for determination of optical rotation

International Organization for Standardization (ISO)

ISO 592:1998 Essential oils - Determination of optical rotation
ISO 5785:1978 Hydrochloric acid for industrial use; Determination of arsenic content; Silver diethyldithiocarbamate photometric method
ISO 3359:1975 Phosphoric acid for industrial use; Determination of arsenic content; Silver diethyldithiocarbamate photometric method
ISO 5792:1978 Sulphuric acid for industrial use; Determination of arsenic content; Silver diethyldithiocarbamate photometric method
ISO 6595:1982 Water quality; Determination of total arsenic; Silver diethyldithiocarbamate spectrophotometric method
ISO 592:1981 Essential oils — Determination of optical rotation
ISO 5786:1978 Ammonium sulphate for industrial use; Determination of arsenic content; Silver diethyldithiocarbamate photometric method
ISO 2590:1973 General method for the determination of arsenic; Silver diethyldithiocarbamate photometric method

AENOR

UNE 84159:2002 Essential oils. Determination of optical rotation.
UNE-EN 12632:2000 FRUIT AND VEGETABLE JUICES. ENZYMATIC DETERMINATION OF ACETIC ACID (ACETATE) CONTENT. NAD SPECTROMETRIC METHOD

AR-IRAM

IRAM 17 715-1960 Purity 28 Acetic Acid for Photography

VN-TCVN

TCVN 6182-1996 Water quality.Determination of total arsenic.Silver diethyldithiocarbamate spectrophotometry method

RO-ASRO

STAS SR 13365-1996 Sodium chloride. Determination of arsenic. Silver Diethyldithiocarbamate Photometric Method
STAS SR ISO 2590:1995 General method for the determination of arsenic -Silver diethyldithiocarbamate photometric method

European Committee for Standardization (CEN)

EN 12632:1999 Fruit and vegetable juices - Enzymatic determination of acetic acid (acetate) content - NAD spectrometric method
EN 26595:1992 Water Quality - Determination of Total Arsenic - Silver Diethyldithiocarbamate Spectrophotometric Method (ISO 6595:1982)

BE-NBN

NBN T 03-264-1980 Phosphoric acid for industrial use - Determination of arsenic content - Silver diethyldithiqcarbamate photometric method
NBN T 03-026-1979 Sulphuric acid for industrial use - Determination of arsenic content -Silver diethyldithiocarbamate photometric method
NBN T 03-008-1979 Hydrochloric acid for industrial use - Determination of arsenic content - Silver diethyldithiorcarbamate photometric method
NBN T 03-072-1979 Ammonium sulphate for industrial use - Determination of arsenic content - Silver diethyldithiocarbamate photometric method
NBN T 03-546-1983 Acid-grade fluorspar - Determination of total phosphrus content -Molybdophosphate photometric method

NL-NEN

NEN-ISO 6595:1993 Water quality. Determination of total arsenic. Silver diethyldithiocarbamate spectrophotometric method (ISO 6595:1982)

DIN

DIN EN 26595:1993 Water quality; determination of total arsenic; silver diethyldithiocarbamate spectrophotometric method (ISO 6595:1982); german version EN 26595:1992

U.S. Military Regulations and Norms

ARMY QPL-52891-15 NOTICE 1-2008 Enamel, Lusterless, Zinc Phosphate, Styrenated, Alkyd Type
ARMY QPL-52891-2012 Enamel, Lusterless, Zinc Phosphate, Styrenated Alkyd Type
ARMY MIL-E-52891 B NOTICE 1-2005 ENAMEL, LUSTERLESS, ZINC PHOSPHATE, STYRENATED ALKYD TYPE
ARMY MIL-E-52891 B VALID NOTICE 2-2010 ENAMEL, LUSTERLESS, ZINC PHOSPHATE, STYRENATED ALKYD TYPE
ARMY QPL-52891-15-1995 ENAMEL, LUSTRELESS, ZINC PHOSPHATE, STYRENATED, ALKYD TYPE
ARMY MIL-E-52891 B-1988 ENAMEL, LUSTERLESS, ZINC PHOSPHATE, STYRENATED ALKYD TYPE

AT-ON

ONORM EN 26595-1993 Water quality - Determination of total arsenic - Silver diethyldithiocarbamate spectrophotometric method (ISO 6595:1982)

SAE - SAE International

SAE AS1638D-2007 "HOSE ASSEMBLY@ CONVOLUTED@ POLYTETRAFLUOROETHYLENE@ METALLIC REINFORCED CONDUCTIVE@ FLARELESS@ 90° TO 90°,,"
SAE AS1638A-1986 Hose Assembly@ Convoluted@ Tetrafluoroethylene@ Flareless@ 90 Degree to 90 Degree
SAE AS1636E-2017 "HOSE ASSEMBLY@ CONVOLUTED@ POLYTETRAFLUOROETHYLENE@ METALLIC REINFORCED CONDUCTIVE@ FLARELESS@ 45° TO 45°,,"
SAE AS1638E-2017 "HOSE ASSEMBLY@ CONVOLUTED@ POLYTETRAFLUOROETHYLENE@ METALLIC REINFORCED CONDUCTIVE@ FLARELESS@ 90° TO 90°,,"
SAE AS1636A-1986 Hose Assembly@ Convoluted@ Tetrafluoroethylene@ Flareless@ 45 Degrees to 45 Degrees

KR-KS

KS M ISO 3705-2017 Sulphur for industrial use — Determination of arsenic content — Silver diethyldithiocarbamate photometric method