for protein contentUV

for protein contentUV, Total:208 items.

The international standard classification for "for protein contentUV" includes: Man-made fibres , Cereals, pulses and derived products , Fruits. Vegetables , Textiles in general , food products in general , Meat and meat products , Tobacco, tobacco products and related equipment .

The Chinese standard classification for "for protein contentUV" includes: Chemical fibre in general , Cereal crop and forage crop in general , Other cash crops , Silk and silk fabric in general , Food processing and products in general , Meat processing and products , Basic standard and general method on forestry , Tobacco .

Professional Standard - Textile

FZ/T 50018-2013 Determination of the protein content of the protein viscose fiber

Professional Standard - Agriculture

2330药典二部-2010 Appendix VII M Determination of protein content
201药典三部-2015 Content Determination Method 0731 General Principles of Protein Content Determination Method 50
NY/T 4306-2023 Determination of activity of papain and bromelain-Ultaraviolet spectrophotometry
651药典第一增补本-2010 Part Two Revised Appendix Appendix VII M Determination of Protein Content
92药典四部-2020 0700 Other Determination Methods 0731 Determination of Protein Content
220药典三部-2020 Content Determination Method 0731 Protein Content Determination Method
111药典四部-2015 0700 Other Determination Methods 0731 Determination of Protein Content
245药典三部-2020 Content Determination Method 3124 Human Granulocyte Stimulating Factor Protein Content Determination Method

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

GB/T 24899-2010 Inspection of grain and oils—Determination of crude protein in wheat—Near-infrared method
GB/T 24901-2010 Inspection of grain and oils—Determination of crude protein in maize—Near-infrared method
GB/T 44214-2024 Test method for non-protein content in silk
GB/T 15673-1995 Method for determination of crude protein in edible fungi
GB/T 5511-2008 Cereals and pulses - Determination of the nitrogen content and calculation of the crude protein content - Kjeldahl method
GB/T 24870-2010 Inspection of grain and oils—Crude protein and crude fat determination in soybean—Near-infrared method
GB/T 24871-2010 Inspection of grain and oils—Crude protein determination in wheat flour—Near-infrared method
GB/T 24897-2010 Inspection of grain and oils—Crude protein determination in rice—Near-infrared method

Tianjin Provincial Standard of the People's Republic of China

DB12/T 347-2007 Near-infrared rapid detection method of crude protein content in wheat and corn

Group Standards of the People's Republic of China

T/GXAS 357-2022 Rapid screening of protein content in fresh wet rice noodles by near infrared spectroscopy
T/FDCA 11-2024 Cosmetic anti-wrinkle and firming efficacy test - Determination of type I collagen content in ultraviolet-induced human fibroblasts
T/HXCY 005-2021 Determination of Crude Protein in Siberian wildrye on Qinghai-Tibet Plateau by Near Infrared Method
T/CAAMM 314-2023 Procedure for rapid grading detection of protein content in fresh edible sweet potatoes using near-infrared spectroscopy
T/HXCY 006-2021 Determination of Crude Protein in Reed Canary Grass on Qinghai-Tibet Plateau by Near Infrared Method

国家市场监督管理总局、中国国家标准化管理委员会

GB/T 41366-2022 Livestock and poultry meat quality testing—Determination of moisture,protein and fat—Near-infrared spectroscopy method

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 35809-2018 Method for analysis of forestry biomass—Determination of protein content

国家能源局

SH/T 0966-2017 Determination of aromatic hydrocarbon content in white oil by UV spectrophotometry

Professional Standard - Tobacco

YC/T 166-2003 Tobacco and tobacco products - Determination of total proteins content(Albumins)

Taiwan Provincial Standard of the People's Republic of China

CNS 6511-2008 Method of test for meat and meat products - Determination of crude protein content

Professional Standard - Commodity Inspection

SN/T 3926-2014 Determination of protein content in dairy foods,egg foods and soy foods for export - Coomassie brilliant blue method

Professional Standard - Medicine

YY/T 1151-2009 Protein microarray for in vitro diagnostics

British Standards Institution (BSI)

BS ISO 5739:2003 Caseins and caseinates - Determination of contents of scorched particles and of extraneous matter
BS EN ISO 8968-4:2016 Milk and milk products. Determination of nitrogen content. Determination of protein and non-protein nitrogen content and true protein content calculation (Reference method)
BS EN ISO 8968-4:2016(2017) Milk and milk products — Determination of nitrogen content Part 4 : Determination of protein and non - protein nitrogen content and true protein content calculation (Reference method)
BS EN ISO 8968-5:2002 Milk. Determination of nitrogen content. Determination of protein-nitrogen content
BS EN ISO 8968-4:2002 Milk. Determination of nitrogen content. Determination of non-protein nitrogen content
BS ISO 5550:2006 Caseins and caseinates - Determination of moisture content (Reference method)
BS EN ISO 21415-4:2007 Wheat and wheat flour - Gluten content - Determination of dry gluten from wet gluten by a rapid drying method
BS ISO 9622:2013 Milk and liquid milk products. Guidelines for the application of mid-infrared spectrometry
BS ISO 5548:2004 Caseins and caseinates - Determination of lactose content - Photometric methods
BS ISO 9622:2000 Whole milk - Determination of milkfat, protein and lactose content - Guidance on the operation of mid-infrared instruments
BS EN ISO 21415-1:2007 Wheat and wheat flour - Gluten content - Determination of wet gluten by a manual method
BS EN ISO 21415-3:2007 Wheat and wheat flour - Gluten content - Determination of dry gluten from wet gluten by an oven drying method

International Organization for Standardization (ISO)

ISO 5739:2003 Caseins and caseinates - Determination of contents of scorched particles and of extraneous matter
ISO 5739:2003|IDF 107:2003 Determination of casein and caseinate coke particles and foreign matter content
ISO 5549:1978 Caseins and caseinates; Determination of protein content (Reference method)
ISO 8968-4:2016 | IDF 20-4:2016 Milk and milk products — Determination of nitrogen content — Part 4: Determination of protein and non-protein nitrogen content and true protein content calculation (Reference method)
ISO 20483:2006 Cereals and pulses - Determination of the nitrogen content and calculation of the crude protein content - Kjeldahl method
ISO 8968-4:2016 Milk and milk products - Determination of nitrogen content - Part 4: Determination of protein and non-protein nitrogen content and true protein content calculation (Reference method)
ISO 8968-5:2001 Milk - Determination of nitrogen content - Part 5: Determination of protein-nitrogen content
ISO 8968-5:2001|IDF 20-5:2001 Determination of milk nitrogen content Part 5: Determination of protein nitrogen content
ISO 5983:1979 Animal feeding stuffs; Determination of nitrogen content and calculation of crude protein content
ISO 8968-5:2001 | IDF 20-5:2001 Milk — Determination of nitrogen content — Part 5: Determination of protein-nitrogen content
ISO 8968-4:2001 Milk - Determination of nitrogen content - Part 4: Determination of non-protein-nitrogen content
ISO 5550:2006|IDF 78:2006 Caseins and caseinates — Determination of moisture content (Reference method)
ISO 8968-4:2001|IDF 20-4:2001 Determination of milk nitrogen content Part 4: Determination of non-protein nitrogen content
ISO 5739:1983 Caseins and caseinates; Determination of scorched particles content
ISO 5550:2006 Caseins and caseinates - Determination of moisture content (Reference method)
ISO 5550:1978 Caseins and caseinates; Determination of water content (Reference method)
ISO 5548:2004 Caseins and caseinates - Determination of lactose content - Photometric method
ISO 5548:2004|IDF 106:2004 Caseins and caseinates — Determination of lactose content — Photometric method
ISO 5548:2004 | IDF 106:2004 Caseins and caseinates — Determination of lactose content — Photometric method
ISO 9622:1999 Whole milk - Determination of milkfat, protein and lactose content - Guidance on the operation of mid-infrared instruments
ISO 5550:2006 | IDF 78:2006 Caseins and caseinates — Determination of moisture content (Reference method)
ISO 5548:1980 Caseins and caseinates; Determination of lactose content; Photometric method
ISO 21415-2:2006 Wheat and wheat flour - Gluten content - Part 2: Determination of wet gluten by mechanical means
ISO 5543:2004 | IDF 127:2004 Caseins and caseinates — Determination of fat content — Gravimetric method (Reference method)
ISO 5543:2004 Caseins and caseinates - Determination of fat content - Gravimetric method (Reference method)
ISO 5543:2004|IDF 127:2004 Gravimetric method for determination of fat content in casein and caseinate (reference method)

Korean Agency for Technology and Standards (KATS)

KS H ISO 5739:2006 Caseins and caseinates－Determination of scorched particles content
KS H ISO 5549:2021 Caseins and caseinates — Determination of protein content(Reference method)
KS H ISO 5549:2006 Caseins and caseinates－Determination of protein content(Reference method)
KS H ISO 5549-2006(2016) Caseins and caseinates－Determination of protein content(Reference method)
KS H 1204-2012 Testing method for crude proteins content
KS H 1204-2001 Testing method for crude proteins content
KS H 1204-2021 Testing method for crude proteins content
KS H ISO 5739-2006(2016) Caseins and caseinates－Determination of scorched particles content
KS H ISO 5739:2021 Caseins and caseinates — Determination of scorched particles content
KS H ISO 5550:2007 Caseins and caseinates－Determination of moisture content(Reference method)
KS H ISO 9622:2006 Whole milk－Determination of milkfat, protein and lactose content－Guidance on the operation of mid-infrared instruments
KS H ISO 5548:2020 Caseins and caseinates－Determination of lactose content－Photometric method
KS H ISO 5548:2006 Caseins and caseinates－Determination of lactose content－Photometric method
KS H ISO 5550-2007(2012) Caseins and caseinates－Determination of moisture content(Reference method)
KS H ISO 5543-2006(2016) Caseins and caseinates－Determination of fat content－Gravimetric method(Reference method)
KS H ISO 5550-2021 Caseins and caseinates－Determination of moisture content(Reference method)
KS H ISO 9622:2021 Whole milk — Determination of milkfat, protein and lactose content — Guidance on the operation of mid-infrared instruments
KS H ISO 5543:2021 Caseins and caseinates — Determination of fat content — Gravimetric method(Reference method)
KS H ISO 5543:2006 Caseins and caseinates－Determination of fat content－Gravimetric method(Reference method)

RO-ASRO

STAS 2213/17-1976 SWEETS Determination of total proteinic content and milk proteinic substance content
STAS 21/6-1973 OILSEED RESIDUES Determination of protein of protein brut content
STAS 6356-1976 MILK AND MILK PRODUCTS Proteic substances determinat ion
STAS SR 4895-6-1997 Tobacco and tobacco prodocts Determination of total proteins content (albumines)
STAS 6514-1975 FISH AND FISH PRODUCTS Determination of total proteic matters

CZ-CSN

CSN 57 0111-5-2002 Testing methods for casein and caseinates - Determination of protein content
CSN 570111-5-2002 Testing methods for casein and caseinates - Determination of protein content
CSN 56 0512-12-1995 Methods of milled produets analysis - Part 12: Determination of protein content
CSN 57 0105 Cast.5-1984 Powdered and condensed milk products. Testing methods. Determination of protein content

Danish Standards Foundation

DS/ISO 5739:2003 Caseins and caseinates - Determination of contents of scorched particles and of extraneous matter
DS/EN ISO 8968-5:2002 Milk - Determination of nitrogen content - Part 5: Determination of protein-nitrogen content
DS/ISO 9622:2000 Whole milk - Determination of milkfat, protein and lactose content - Guidance on the operation of mid-infrared instruments

International Dairy Federation (IDF)

IDF 107-2003 Caseins and caseinates - Determination of contents of scorched particles and of extraneous matter
IDF 20-5-2001 Milk - Determination of nitrogen content - Part 5: Determination of protein-nitrogen content
IDF 20-4-2001 Milk - Determination of nitrogen content - Part 4: Determination of non-protein-nitrogen content
IDF 78-2006 Caseins and caseinates. Determination of moisture content (Reference method)

KR-KS

KS H ISO 5549-2021 Caseins and caseinates — Determination of protein content(Reference method)
KS H 1204-2022 Testing method for crude proteins content
KS H ISO 5739-2021 Caseins and caseinates — Determination of scorched particles content
KS H ISO 5548-2020 Caseins and caseinates－Determination of lactose content－Photometric method
KS H ISO 9622-2021 Whole milk — Determination of milkfat, protein and lactose content — Guidance on the operation of mid-infrared instruments
KS H ISO 5543-2021 Caseins and caseinates — Determination of fat content — Gravimetric method(Reference method)

German Institute for Standardization

DIN 10464:1994 Determination of casein content, casein and whey protein contents in total protein of milk and milk products - Casein-phosphorus method
DIN EN ISO 8968-4:2016-09 Milk and milk products - Determination of nitrogen content - Part 4: Determination of protein and non-protein nitrogen content and true protein content calculation (Reference method) (ISO 8968-4:2016); German version EN ISO 8968-4:2016
DIN 10470:2011 Milk and milk products - Determination of whey protein content and casein content in total protein - Derivative spectroscopic method
DIN 10464:1994-08 Determination of casein content, casein and whey protein contents in total protein of milk and milk products - Casein-phosphorus method
DIN 10470:1999 Determination of whey protein content and casein content in total protein of milk and milk products - Derivative spectroscopic method
DIN EN ISO 8968-4 E:2013-09 Determination of nitrogen content of milk and milk products Part 4: Determination of protein and non-protein nitrogen content and calculation of pure protein content (Reference Method) (Draft)
DIN 10466:2001 Determination of whey protein content in total protein of milk and milk products - Polarographic method
DIN 10470:2011-07 Milk and milk products - Determination of whey protein content and casein content in total protein - Derivative spectroscopic method
DIN EN ISO 8968-4:2016 Milk and milk products - Determination of nitrogen content - Part 4: Determination of protein and non-protein nitrogen content and true protein content calculation (Reference method) (ISO 8968-4:2016); German version EN ISO 8968-4:2016
DIN EN ISO 8968-5:2002 Milk - Determination of nitrogen content - Part 5: Determination of protein-nitrogen content (ISO 8968-5:2001); German version EN ISO 8968-5:2001
DIN EN ISO 8968-4:2002 Milk - Determination of nitrogen content - Part 4: Determination of the non-protein-nitrogen content (ISO 8968-4:2001); German version EN ISO 8968-4:2001
DIN ISO 9622 E:2016-04 Whole milk - Determination of milkfat, protein and lactose content - Guidance on the operation of mid-infrared instruments
DIN ISO 9622:2000 Whole milk - Determination of milkfat, protein and lactose content - Guidance on the operation of mid-infrared instruments (ISO 9622:1999)
DIN EN ISO 21415-2:2008 Wheat and wheat flour - Gluten content - Part 2: Determination of wet gluten by mechanical means (ISO 21415-2:2006); English version of DIN EN ISO 21415-2:2008-04
DIN ISO 5550 E:2020-06 Caseins and caseinates - Determination of moisture content (Reference method)
DIN ISO 5550:2020-12 Caseins and caseinates - Determination of moisture content (Reference method) (ISO 5550:2006)
DIN 10466:2001-09 Determination of whey protein content in total protein of milk and milk products - Polarographic method

SCC

AWWA WQTC71633 Protein Damage in UV Treated Adenovirus
DANSK DS/EN ISO 8968-4:2016 Milk and milk products – Determination of nitrogen content – Part 4: Determination of protein and non-protein nitrogen content and true protein content calculation (Reference method)
NS-EN ISO 8968-4:2016 Milk and milk products — Determination of nitrogen content — Part 4: Determination of protein and non-protein nitrogen content and true protein content calculation (Reference method) (ISO 8968-4:2016)
AENOR UNE-EN ISO 8968-4:2016 Milk and dairy products. Determination of nitrogen content. Part 4: Determination of protein and non-protein nitrogen content and calculation of true protein content (Reference method). (ISO 8968-4:2016)
DIN EN ISO 8968-4 E:2013 Draft Document - Milk and milk products - Determination of nitrogen content - Part 4: Determination of protein and non protein nitrogen content and true protein content calculation (Reference method) (ISO/DIS 8968-4:2013); German version prEN ISO 8968-...
DIN 10470 E:2010 Draft Document - Milk and milk products - Determination of whey protein content and casein content in total protein - Derivative spectroscopic method
BS ISO 9622:1999 Whole milk. Determination of milkfat, protein and lactose content. Guidance on the operation of mid-infrared instruments

GSO

GSO ISO 8968-4:2021 Milk and milk products — Determination of nitrogen content — Part 4: Determination of protein and non-protein nitrogen content and true protein content calculation (Reference method)
BH GSO ISO 8968-4:2022 Milk and milk products — Determination of nitrogen content — Part 4: Determination of protein and non-protein nitrogen content and true protein content calculation (Reference method)
GSO 2101:2010 Protein-Rich concentrated Nutrient Supplementary foods
GSO ISO 8968-5:2014 Milk -- Determination of nitrogen content -- Part 5: Determination of protein-nitrogen content
NB/SH/T 0966-2017 Determination of aromatics content in white oil - UV spectrophotometry
OS GSO ISO 8968-5:2014 Milk -- Determination of nitrogen content -- Part 5: Determination of protein-nitrogen content
OS GSO ISO 5548:2015 Caseins and caseinates -- Determination of lactose content -- Photometric method
GSO ISO 5550:2015 Caseins and caseinates -- Determination of moisture content (Reference method)
BH GSO ISO 5543:2016 Caseins and caseinates -- Determination of fat content -- Gravimetric method (Reference method)
OS GSO ISO 5543:2015 Caseins and caseinates -- Determination of fat content -- Gravimetric method (Reference method)
GSO ISO 5548:2015 Caseins and caseinates -- Determination of lactose content -- Photometric method
OS GSO ISO 5550:2015 Caseins and caseinates -- Determination of moisture content (Reference method)
GSO ISO 5543:2015 Caseins and caseinates -- Determination of fat content -- Gravimetric method (Reference method)
GSO ISO 5983:2002 ANIMAL FEEDING STUFFS – DETERMINATION OF NITROGEN CONTENT AND CALCULATION OF CRUDE PROTEIN CONTENT
BH GSO ISO 5739:2016 Caseins and caseinates -- Determination of contents of scorched particles and of extraneous matter

Standard Association of Australia （SAA）

AS ISO 8968.4:2021 Milk and milk products — Determination of nitrogen content, Part 4: Determination of protein and non-protein nitrogen content and true protein content calculation (Reference method)

AT-ON

ONORM DIN 10454-1993 Determination of protein content of caseins and caseinates - Reference method
ONORM DIN 10453-1993 Determination of water content of caseins and caseinates - Reference method

Association Francaise de Normalisation

NF EN ISO 8968-4:2016 Milk and dairy products - Determination of nitrogen content - Part 4: determination of protein and non-protein nitrogen content and calculation of true protein content (Reference method)
NF V04-221-4*NF EN ISO 8968-4:2016 Milk and milk products - Determination of nitrogen content - Part 4 : determination of protein and non-protein nitrogen content and true protein content calculation (Reference method)
NF V04-387:1985 Caseins and caseinates. Determination of protein content (reference method).
NF EN 15948:2020 Cereals - Determination of water and protein content - Method using near-infrared spectroscopy on whole grains
NF V04-221-5:2002 Milk - Determination of nitrogen content - Part 5 : determination of protein-nitrogen content.
NF V04-389:1985 Caseins and caseinates. Determination of scorched particles content.
NF V04-388*NF ISO 5548:2008 Caseins and caseinates - Determination of lactose content - Photometric method.
NF V04-221-4:2002 Milk - Determination of nitrogen content - Part 4 : determination of non-protein nitrogen content.
NF ISO 5548:2008 Caseins and caseinates - Determination of lactose content - Photometric method
NF V04-382:1988 Caseins and caseinates. Determination of fat content. Gravimetric method (reference method).
NF ISO 5550:2007 Caseins and caseinates - Determination of moisture content (reference method)
NF V18-100:1977 Animal feeding stuffs.determination of nitrogen for the calcultion of crude protein content.
NF V04-382:2008 Caseins and caseinates - Determination of fat content - Gravimetric method (Reference method).

Spanish Association for Standardization (UNE)

UNE-EN ISO 8968-4:2016 Milk and milk products - Determination of nitrogen content - Part 4: Determination of protein and non-protein nitrogen content and true protein content calculation (Reference method) (ISO 8968-4:2016)
UNE 34-871-1986 Processed cheese. Determination of protein content
UNE 34871:1986 PROCESSED CHEESE PRODUCTS. DETERMINATION OF THE PROTEIN CONTENT.
UNE-EN ISO 8968-5:2002 Milk - Determination of nitrogen content - Part 5: Determination of protein-nitrogen content. (ISO 8968-5:2001)
UNE 34827:1983 DETERMINATION OF THE CASEIN CONTENT OF MILK.

RU-GOST R

GOST 10846-1991 Grain and products of its processing. Method for determination of protein
GOST R 51470-1999 Caseins and caseinates. Method for determination of protein content
GOST R 51454-1999 Caseins and caseinates. Method of determination of nitrate and nitrite contents
GOST R 51464-1999 Caseins and caseinates. Method for determination of water content
GOST R 51465-1999 Caseins and caseinates. Determination of scorched particles content
GOST 13496.4-1984 Fodder, mixed fodder and animal feed raw stuff. Methods of nitrogen and crude protein determination
GOST R 52993-2008 Caseins and caseinates. Determination of moisture content (Reference method)
GOST 13496.4-1993 Fodder, mixed fodder and animal feed raw stuff. Methods of nitrogen and crude protein determination
GOST R 51469-1999 Caseins and caseinates. Photometric method for determination of lactose content
GOST R 51463-1999 Rennet caseins and caseinates. Method for determination of ASH content

Lithuanian Standards Office

LST ISO 5549:2001 Caseins and caseinates. Determination of protein content (Reference method) (identical ISO 5549:1978)

CEN - European Committee for Standardization

EN ISO 8968-4:2001 Milk - Determination of Nitrogen Content - Part 4: Determination of Non-Protein Nitrogen Content

HU-MSZT

MSZ 05 26.1510-1983 Protein content 40-150
MNOSZ 17619-1954 Definition of the concept of protein content in preserved foods
MSZ 12325-1982 Main protein content of milk
MNOSZ 6832-1952 Feed desiccant, hardener and digestible protein content
MSZ KGST 2787-1980 Determination of protein content of preservative foods

Japanese Industrial Standards Committee (JISC)

JIS K 0602:2000 Proteins -- Serum albumin -- Methods for quantitative analysis
JIS K 0605:2000 Proteins -- Trypsin -- Methods for quantitative analysis
JIS K 0606:2000 Proteins -- Transferrin -- Methods for quantitative analysis
JIS K 0603:2000 Proteins -- Immunoglobulin -- Methods for quantitative analysis

PL-PKN

PN C04288-14-1987 Technical fats Methods of testing Determination of protein content

European Committee for Standardization (CEN)

EN ISO 8968-4:2016 Milk and milk products - Determination of nitrogen content - Part 4: Determination of protein and non-protein nitrogen content and true protein content calculation (Reference method)
EN ISO 21415-2:2008 Wheat and wheat flour - Gluten content - Part 2: Determination of wet gluten by mechanical means

South African Bureau of Standard

SANS 5218:2007 Water - Albuminoid ammonia content
SANS 8968-5:2006 Milk - Determination of nitrogen content - Part 5: Determination of protein-nitrogen content
SANS 8968-4:2006 Milk - Determination of nitrogen content Part 4: Determination of non-protein-nitrogen content
SANS 6039:2005 Amylaceous and proteinaceous matter detection in wood adhesives
SANS 9622:2005 Whole milk - Determination of milkfat, protein and lactose content - Guidance on the operation of mid-infrared instruments

VN-TCVN

TCVN 7871-3-2008 Wheat and wheat flour.Gluten content.Part 3: Determination of dry gluten from wet gluten by an oven drying method
TCVN 7871-4-2008 Wheat and wheat ftour.Gluten content.Part 4: Determination of dry gluten from wet gluten by a rapid drying method
TCVN 3705-1990 Aquatic products.Method for the determination of total nitrogen and protein content
TCVN 7253-2003 Tobacco and tobacco products.Determination of nitrogen protein content

GOSTR

GOST 34454-2018 Dairy products. Determination of protein content by the Kjeldahl method
GOST 13496.4-2019 Fodder, мixed fodder and raw mixed fodder. Methods of nitrogen and crude protein determination

IN-BIS

IS 7487-1986 Specifications for protein-rich cookies
IS 1167-1965 Casein specifications (food quality)

Society of Automotive Engineers (SAE)

SAE AMS1800-2011 FOAM, FIRE EXTINGUISHING LIQUID Protein and Fluoroprotein

TN-INNORPI

NT 14.51-1983 Determination of casein content in milk