Thermo Scientific
| Reagents, Solvents and Accessories
11
HMDS
The popular choice for silylation of sugars and related
substances.
HMDS
MW 161.4
bp 125
˚
C
n
d
20
1.4071
Si
CH
3
NH
Si
CH
3
CH
3
CH
3
CH
3
CH
3
Thermo Scientific HMDS greatly extends the practical range
of GC, improving chromatographic results in the silylation
of sugars and related substances.
A critical study of the optimal proportions of HMDS and
trimethylchlorosilane for producing maximum yield of
trimethylsilyl derivatives was conducted by Sweeley,
et al.
PROTOCOL 1
This protocol describes the method of Sweeley,
et al.
for the
trimethylsilylation of sugars and related substances.
1. Combine 10 mg or less carbohydrate sample, 1.0 ml anhydrous pyridine,
0.2 ml HMDS and 0.1 ml TMCS in a 3.0 ml Thermo Scientific Reacti-Vial
Small Reaction Vial.
2. Cap vial and shake vigorously 30 seconds.
3. Let stand at room temperature 5 minutes or until derivatization is
complete.
4. Analyze by gas chromatography.
NOTE:
Solution may become cloudy when TMCS is added, due to fine
precipitate of ammonium chloride. Precipitate will not interfere with gas
chromatography. Carbohydrates may be warmed for 10-20 minutes at
75-85°C to hasten dissolution.
PROTOCOL 2
This method was developed primarily for silylating syrups and
concentrated aqueous solutions of sugars such as starch hydrolyzates.
CAUTION: Considerable heat, ammonia gas and pressure emit during
reaction. Do not premix.
1. Place 60-70 mg of 80% solids syrup in a 3.0 ml Thermo Scientific
Reacti-ViaI Small Reaction Vial.
2. Add 1.0 ml pyridine and dissolve.
3. Add 0.9 ml HMDS and mix.
4. Add 0.1 ml trifluoroacetic acid.
5. Shake vigorously 30 seconds.
6. Let stand 15 minutes.
7. Analyze by gas chromatography.
Ordering Information
Product # Description
Pkg. Size
TS-84770
HMDS
25 g
(Hexamethyldisilazane)
Hypo-Vial Sample
Storage Vial
✖
TS-84769
HMDS
100 g
Hypo-Vial Sample
Storage Vial
✖
Additional hazardous handling charge.
TMCS
An excellent catalyst for difficult-to-silylate compounds.
20
TMCS
MW 108.7
bp 57.6
˚
C
d
4
0.858
Si
CH
3
CH
3
CH
3
CI
Thermo Scientific TMCS (trimethylchlorosilane) provides an
excellent adjunct for forming trimethylsilyl ethers for GC
determinations. In addition, it is used for preparing TMS
derivatives of organic acids.
PROTOCOL
This protocol describes the method of Sweeley,
et al.
for the
trimethylsilylation of sugars and related substances.
1. Combine 10 mg or less carbohydrate sample, 1.0 ml anhydrous pyridine,
0.2 ml HMDS and 0.1 ml TMCS in a 3.0 ml Thermo Scientific Reacti-Vial
Small Reaction Vial.
2. Cap vial and shake vigorously 30 seconds.
3. Let stand at room temperature 5 minutes or until derivatization is
complete.
4. Analyze by gas chromatography.
NOTE:
Solution may become cloudy when TMCS is added due to fine
precipitate of ammonium chloride. Precipitate will not interfere with
gas chromatography. Carbohydrates may be warmed for 10-20 minutes
at 75-85°C to hasten dissolution.
Ordering Information
Product # Description
Pkg. Size
TS-88530
TMCS (Trimethylchlorosilane)
25 g bottle
