About us

SHOKO Science Co.,Ltd. which has succeeded a stable isotope business of Shoko Co.,Ltd. was founded on October 1, 2009.

Our stable isotope business has started by introducing technology of enriching 15N from the Institute of Physical and Chemical Research in 1972. Since then we manufactures 15N enriched compounds as a sole manufacturer in Japan.

Moreover we supply various kinds of stable isotope chemicals. Besides we have business of analysis of stable isotopes and purchasing relating expendable supplies.

Standard Reference Compounds for stable isotope ratio mass spectrometry (IRMS)


We believed that compound-specific stable isotope analysis (CSIA) of amino acids is challenging but it makes a breakthrough in a number of fields of studies particularly in ecology and biology. We are recently trying to reduce difficulties on CSIA and to enhance user friendliness of this technique.
As one of the projects, we carefully developed isotopic reference materials of amino acids for the d15N analysis on the CSIA,which are commercially available now.

SHOKO Science Co.,Ltd manufactures working reference standards valued with the international standard by us such as Amino standardsTM and Aqua standardsTM.
Amino standardsTM are usually used for EA-IRMS and GC-IRMS.
Aqua standardsTM are used for IR-analysis of water. 
These standards cover the range of IR values of natural abundance.
Recently SHOKO Science Co., Ltd. started providing more extensive Amino standards TM by the cooperation with Indiana University.  They increase the kind of amino acids and expand the range of δ15N.

Amino Standard®

Amino standard Product No. Lot No. δ13CvsVPDB δ15NvsAir
L-Histidine AZ1Z0 M6M9675 -11.4 -7.60
L-Alanine AZ1Z0 M5R9452 -19.9 -1.20
L-Alanine AZ1Z0 M8A0384 -18.5 -1.02
Glycine AZ300 M9R2283 -32.3 1.12
L-Alanine AZ100 M9R2064 -19.9 1.79
L-Alanine AZ100 SS05 -19.6 3.70
L-Alanine AZ100 M6R397405 -19.6 5.00
L-Alanine AZ100 SS09 -19.6 8.70
L-Alanine AZ101 M6R397410 -19.6 10.1
L-Alanine AZ101 SS13 -19.6 13.7
L-Alanine AZ101 SS16 -19.6 16.1
L-Alanine AZ102 M0H912820 -19.9 20.6
L-Alanine AZ102 SS25 -19.6 26.1
                            *Minimum sales amount : 1g

for GC-IRMS   

Amino standard Product No. Lot No. δ13CvsVPDB δ15NvsAir
D-Glucose AA3 CLPR22981CIL -133.06 -
L-Alanine AZ104-01 M0R3337N40 -17.93 43.25
Glycine AZ6Z2 CNLEK2218VALD -60.02 -26.35
L-Leucine AZ200 LAH0629 -28.36 6.22
L-(+)-Norleucine AZ201 LAM3141mix -28.85 18.96
L-Aspartic Acid AZ203 M1B6432N35 -23.95 35.20
L-Methionine AZ2Z0 D00129520 -29.40 -3.79
L-Valine #3 A0006 Indiana L-Valine #3 0.49 61.53
Phenylalanine AZ100-01 M0N1811NA -11.20 1.70
L-Hydroxyproline AZ1Z0 LAM3262 -12.66 -9.17
Amino Acid Set 9** ACZ1Z2NZ204SET - - -
                           *Minimum sales amount : 0.1g
  * δ- value is determined by Indiana University
  * Glycine, L-Valine #3 and L-Phenylalanine are also supplied by Indiana University
  **; Each 3nmol /μl of Asp, Val, Ala, Phe, Gly, Met, Leu, Ile, Hyp in 10ml soln..

Please refer to the page of " List of reference materials for EA-IRMS" in http://mypage.iu.edu/~aschimme/compounds.html

Aqua Standard®

Aqua standard Product No. δDvsVSMOW δ18OvsVSMOW
DOW W0000-02 -0.27 -0.086
SLW2 W0102-02 -70.8 -10.82
ICE2 W0202-02 -106.3 -14.51
DOW2 WZ0Z0-02 -5.28 -1.19
SLW3 WZ6Z1-02 -70.1 -10.47
DSW WA1Z2-02 -188.8 -27.52

                      *Minimum sales amount : 20ml x 1 or 12Φx32㎜ vial x 10
*Packing and Transportation fee : USD100 per 1 parcel.
*All prices are in U.S. dollars and are subject to change without notice.
*All values of isotope ratio are subject to change without notice.

Packaged Standards
SHOKO Science Co.,Ltd. also provides the encapsulated Amino Standards with tin container which will be adjusted to the sensitivity of your EA-IRMS.  They will surely make your work more efficient.  The selling unit is a well-plate with 96 encapsulated Amino Standards.


SHOKO Science Co.,Ltd. provides various kinds of Standard reference compounds for stable isotope ratio mass spectrometry (IRMS) including international standards from IAEA, NIST, Indiana University and Oztech as below.

References materials