I used SciFinder to find this colorimetric method: Tholen, JT.; Shifeng, S; Truscott, RJW; "The thymol method for glucosinolate determination " Journal of the Science of Food and Agriculture (1989), 49(2), 157-65.                                   

http://onlinelibrary.wiley.com/doi/10.1002/jsfa.2740490204/abstract

 Dear Bruce Levison

I could not caught it would you please pass it to me as PDF  

You can use the following protocol. Copied from our paper Hanschen et al. (2012) J. Agric. Food Chem. 2012, 60, 9890−9899.

"Quantitation of Intact GSLs as Desulfo-GSLs by HPLC−DAD. A total of 100 μL of

extract solution, 100 μL of a 1 mM stock solution of the internal standard 4-hydroxybenzyl GSL (sinalbin), and 2 mL of water were mixed and directly applied on a

150 μL DEAE−Sephadex A-25 ion-exchanger column, prepared, and

washed according to the method by Mewis et al.32 Next, 100 μL of a

purified arylsulfatase solution were applied to the column and left for

12 h before the desulfo-GSLs were eluted with 1.5 mL of water.

Samples containing broccoli sprouts powder were first extracted for 10

min in a methanol/water mixture (7:3, v/v; T = 75 °C). After

centrifugation at 18620g for 5 min, the supernatant was restocked with

water to 2 mL. A total of 200 μL of this extract was then applied on

the Sephadex A-25 ion-exchanger column, and a total of 100 μL of 4-

hydroxybenzyl-GSLs (1 mM) was added. The samples were

desulfated, as described above in this section. Desulfated extracts

were separated and analyzed by HPLC−DAD [HPLC pump LC-9A,

degasser DGU-4A, gradient mixer FCV-10 AL, photodiode array

ultraviolet−visible (UV−vis) detector SPD-M6A (all Shimadzu,

Duisburg, Germany), and JASCO automatic sampler AS-950 (Gross-

Umstadt, Germany)], as described previously.16 Separation was carried

out on a ProntoSIL Spheribond ODS2 column (3 μm, 125 × 4 mm)

(BISCHOFF Chromatography, Leonberg, Germany) and a gradient of

0−20% acetonitrile in water from 2 to 34 min, followed by 20%

acetonitrile in water until 40 min, and then 70% acetonitrile for 10 min

until 50 min. The flow rate was 0.7 mL min−1, and GSLs were detected

at a wavelength of 229 nm. The GSL content was calculated using 4-

hydroxybenzyl-GSL as the internal standard and the response factor

(RF) of compound 6 in relation to desulfo-4-hydroxybenzyl-GSL."

Dear Sascha Rohn

can you please send me PDFs if you do not mind