41000 HPLC kit o-cresol p-cresol phenol urine

o-Cresol, p-Cresol and Phenol in Urine - HPLC

Order no.: 41000
100 Tests
  • o-Cresol
  • p-Cresol
  • Phenol

Easy sample preparation
Efficient acid hydrolysis
With custom-made internal standard


Clinical relevance

Cresol and phenol are formed as metabolites in the body after exposure to toluene and benzene respectively. Toluene and benzene are toxic substances which are used on an industrial scale e.g. as solvents and fuel additives. Determination of the metabolite concentration in people exposed at work is performed as a measure for the occupational health monitoring of toluene and benzene exposure at work.

For any hazardous substance or its metabolite, a BTV (Biological Tolerance Value) is defined as a threshold value for maximum exposure, which assures safe working conditions without detriment to the health of the employee. If insufficient toxicological data is available to define a BTV, the so-called Biological Guideline Value (BGV) is suggested. With carcinogenic substances, generally no BTVs are defined, and the BGV should be used instead.


Product advantages

  • Easy sample preparation
  • Efficient acid hydrolysis
  • With tailor-made internal standard


This Chromsystems kit allows for reliable and fast chromatographic determination of ortho- and para-cresol as well as phenol in an isocratic HPLC run. Sample preparation is fast and simple and requires only two steps: The first step is the acid hydrolysis, in which the phenols present in the form of sulphate and glucuronide conjugates are transformed efficiently into the free form.

The typical problems that occur in enzymatic cleavages, such as long reaction time or incomplete release, are avoided. In the second step, the samples are stabilised by adding a special buffer. The analytes are then measured using optimised chromatographic separation with highly sensitive fluorescence detection, so that potential interferences are mostly excluded. The inclusion of a tailor-made internal standard assures high precision and reliability in quantifying the analytes.


Technical Data

Method of Analysis


Number of Tests



o-Cresol, p-Cresol, Phenol

Analysis Time

14 min

Limit of quantification

0,03 mg/l (o-, p-Cresol: 0.04 mg/l)


Phenol: up to 51 mg/l
o-Cresol: up to 21 mg/l
p-Cresol: up to 202 mg/l


97 - 100 %


CV < 3 %


CV < 4 %

Column temperature

30 °C

Flow rate

1.3 ml/min

Reference ranges

Occupational tolerance limits in urine

Total phenol: 200 mg/l (BGV)
Total cresol: 200 mg/l (BGV)
o-cresol (as metabolite of toluene): 1.5 mg/l (BTV)

Reference range in urine (mg/g creatinine)

Total phenol: 4.5-20.7
p-Cresol: 5.5-65
o-Cresol: n.d.



Pre-analytic Treatment

Stability of specimens

Urine tubes with hexamethylenetetramine (urotropine) as stabiliser are not suitable for the analysis of phenols using this method. The signal intensities of the analytes and the internal standard are impaired; in the worst case, the signal can be lost completely.

Sample Preparation

  • 100 µl Urine
    150 µl Hydrolysis Reagent
    and 50 µl Internal Standard
    in a hydrolysis vial*, seal tightly and mix briefly.
  • Incubate 30 min at 95 °C.
  • Let the sample cool down (approx. 5 min at ambient temperature).
  • Add 600 µl Stabilisation Buffer, seal vial again, mix briefly.
  • Inject 10 µl into the HPLC system.

*The hydrolysis vials are suitable as sample vials for a number of commonly used autosamplers.

Sample Stability

At ambient temperature 3 days, at +2 to +8 °C up to 4 weeks and below -18 °C up to 2 months.

Injection Volume

10 µl

Additional Info

For the Chromsystems HPLC analysis of o-cresol, p-cresol and phenol in urine any isocratic HPLC system with fluorescence detector is suitable.


EX 270 nm, EM 300 nm

Please note

The freely available information on this website, in particular on the sample preparation, are not sufficient to work with our products. Please read instructions and warning notices on products and/or instruction manuals.

Kit Components

Components available separately


Calibrators available separately


Controls available separately