Re-advertisement of contract number Q23/504/NS: Quotations are hereby invited for the following: Supply and deliver PTS for Lab. Scope: Provide Proficiency Testing Scheme (PTS) samples for soil testing section as part of the requirements from ISO 17025 standard to assess the validity of the laboratory results as to maintain the status of accreditation. The PTS includes the following tests: - Metals in Soil (Co, Mo, V, Pb, Ni, Cd, Cr, As, Se, Sb, Ca, MG, Na, K, K, Fe, Mn, Cu, Zn, Ba, B, U, Hg); - Nutrients in soil (TKN, TP and Ammonia); - Anions in soil (Nitrate, Nitrite, Sulphates, SRP); - Corrosively (pH). (投標 №91606387cn)