Baljet reagent probably does not work for all lactones. It is reported to work less efficiently for bufadienolides than for cardenolides (I don't know if it works for saturated lactones). You may try a general reagent :

Hydroxylamine - iron(III) chloride for lactones, esters, amides and anhydrides of carboxylic acids.

Solution a: Dissolve 20 g hydroxylammonium chloride in 50 ml water, make up to 200 ml with ethanol. Store the solution in the refrigerator.

Solution b: Dissolve 50 g potassium hydroxide in as little water as possible and make up to 500 ml with ethanol.

Spray solution I: Mix equal parts of a and b and filter off the precipitated potassium chloride. Place the solution in the refrigerator (stable for about 2 weeks).

Spray solution II: Dissolve 10 g finely powdered iron(III) chloride in 20 ml 36% hydrochloric acid. Shake with 200 ml diethyl ether until a homogenous mixture is obtained. The solution II is stable for some time only well sealed.

Procedure: Spray with I, dry at room temperature and spray with II.

Literature:

V.P. Whittaker, S. Wijesundera, Biochem. J. 51, 348 (1952).

Sounds good, I will try,

Thank you very much