Substitution of N,N-dimethylformamide with ethanol in analysis of alkaline phosphatases in leukocytes.

Number

007-EN

Section

General Section

Use

Sector

Health services
Scientific research and development

Function

Solvent

Process

Use as laboratory reagen

Product category

laboratory chemicals

Application

Bloodanalyzis

Abstract

N,N-dimethylformamide is used in a method to measure activity of the enzyme alkaline phosphatase in leukocytes. N,N-dimethylformamide is specifically used as a solvent to prepare a substrate solution for the method and can easily be substituted with ethanol without any changes in the procedure. The only difference is that ethanol is slightly slower as a solvent than N,N-dimethylformamide.

Substituted substances

N,N-dimethylformamide

CAS No. 68-12-2 EC No. 200-679-5 Index No. 616-001-00-X

Chemical group

Carbonsäureamide

Classification: hazard statements

H360D May damage the unborn child
H332 Harmful if inhaled
H312 Harmful in contact with skin
H319 Causes serious eye irritation

Alternative Substances

Ethanol

CAS No. 64-17-5 EC No. 200-578-6 Index No. 603-002-00-5

Chemical group

Alkohol

Classification: hazard statements

H225 Highly flammable liquid and vapour

Other adverse effects

Der Stoff ist: ein 1 Karzinogen (IARC); wie der Datenbank der nach SUBSPORT-Kriterien gefährlichen Stoffe zu entnehmen ist.

Reason substitution

CMR
other toxic effects
ecotoxicity
physical hazards

Hazard Assessment

The alternative, ethanol, is included in in the database of hazardous substances according to SUBSPORT screening criteria (SDSC), however only for presence in alcoholic beverages, which this is not. Ethanol is also flammable. Dimethylformamide is also on the SDSC and is irritating to eyes, harmful by inhalation and skin contact and may cause harm to the unborn child.

Description of Substitution

N,N-dimethylformamide is used in a method for laboratory analysis of human blood in preparation of the substrate solution, to dissolve the substrate naphtol-AS-phosphate. N,N-dimethylformamide is toxic to reproduction and harmful to inhale and in contact with skin and eyes. It was found that ethanol could be used as an alternative solvent. Ethanol was a bit slower than the original solvent to dissolve naphtol-AS-phosphatase, but otherwise there was no need to revise the method and the final results of the analysis were not any different from when using the original solvent. It was therefore decided to change to ethanol which is not as harmful for the health. Description of procedure or technology (including pre-/post-processing) Some solvents can be used in a method for laboratory analysis of human blood. The method is used to measure activity of the enzyme alkaline phosphatase in leukocytes. The amount of this enzyme is correlated to certain diseases. The enzyme alkaline phosphatase in leukocytes hydrolyses the substrate naphtol- AS- phosphate. Free naphtol binds to the dizoniumsalt Fast Blue BB, whereby a blue precipitate is formed in the cells having enzyme activity, and this can be measured. Way of application: e.g. spraying, dipping, open/closed system etc. Risk management measures (technical, organizational and personal) Risk reduction by alternative: Human health: e.g. more/less safety measures e.g. technical/operational/personal protection measures N,N-dimethylformamide is hazardous and thereby there is a health concern for the person performing the analysis. Ethanol is much safer solvent to use in this application. Risk reduction by alternative: Environment: e.g. waste reduced/increased

Case/substitution evaluation

Advantage or Disadvantage of alternative

Aspect

Advantage/disadvantage to conventional process

Technical requirements

Implementation

Naphtol-AS-phosphate dissolves somewhat slower in ethanol than in N,N-dimethylformamide, however when it has been dissolved there is no changes in the outcome of the analysis, which has been verified in comparative studies of different solvents.

Operational expenses


etc.
Ethanol is available in most laboratories, if not all.

State of implementation

Full capacity

Date and place of implementation

2005 in Sweden

Enterprise using the alternative

Sahlgrenska University Hospital, Sweden. Department for special haematology and reagent preparation in the laboratory for clinic
http://www.sahlgrenska.se/en/

Availability ofAlternative

Available in most laboratories, if not all.

Producer/Provider

Any company selling laboratory chemicals.

Contact

Any company selling laboratory chemicals.

Date, reviewed

February 9, 2022