Who we are

PROOF-ACS GmbH is an independent company, solely financed by organisation of competence schemes and the distribution of reference materials. Four shareholders only allow flat hierarchies and a fast decision-making process.

Therefore, PROOF is able to assess analytical results in an independent way – detached from any external parties.

Shareholders are:

  • Dr. Silke Bruns
  • Dr. Günter Lach
  • Dr. Birgit Schindler
  • Dr. Ralph-Matthias Schoth

Dr. Silke Bruns, Dr. Günter Lach and Dr. Ralph-Matthias Schoth are acting as consultants and support the business development of PROOF-ACS.


Dr. Birgit Schindler

Operates and generally manages the business of PROOF-ACS GmbH from the very beginning in 2013 until today.

Dr. Birgit Schindler has in-depth, hands-on experience in analytical method development in complex matrixes and in method validation. As a research scientist she published several articles in high-ranking international journals and presented her work in national and international conferences. She has multi-annual experiences with External Quality Assessment Schemes from both perspectives: of the participant as well as of the organiser.

Degree as European Registered Toxicologist / Fachtoxikologin DGPT after successfully participation in multi-annual training courses of the German Society for Experimental and Clinical Pharmacology and Toxicology (DGPT).
2009 to 2012
Deputy head of the laboratory Human Biomonitoring (Department Toxicology) at the Institute for Prevention and Occupational Medicine of the German Social Accident Insurance. The working team of Dr. Birgit Schindler was responsible for the Quality Assurance and the organisation and realisation of the External Quality Assessment Schemes in the pan-European COPHES project.
Doctoral degree (Dr. rer. nat/PhD) in Occupational Toxicology and Analytical Chemistry at the Institute of Occupational, Social and Environmental Medicine of the Friedrich-Alexander University Erlangen, Germany. PhD thesis: "Development and Application of Analytical Methods to Quantify Metabolites of Organophosphorus Flame Retardants in Human Body Fluids".
2005 to 2009
Along with the PhD studies - scientific secretary of the working group "Analytical Chemistry, Analyses in Biological Material" of the "Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area" of the German Research Foundation (DFG).
University diploma in Chemistry with focus on Analytical Chemistry and Toxicology (Friedrich-Alexander-University of Erlangen, Germany).