Do you need control materials to validate your methods or carry out your quality control?

In addition to organizing proficiency testing schemes, we provide you with leftover samples from proficiency testing rounds in the agri-food and environmental fields. These are available for laboratories that wish to develop internal quality controls with safe samples. All of them come with a certificate that includes:

  • Assigned value and associated uncertainty, and the number of laboratories assigning it
  • Details about the nature of the sample, representative of the matrices commonly analyzed

GSCA-1/2025

Drinking water

M1: Chlorides (mg/L) Conductivity at 20ºC (µS/cm) Fluorides (mg/L) Phosphates (mg/L as phosphate ion) Total phosphorus (mg/L P) Nitrates (mg/L) Nitrites (mg/L) pH (pH units) Potassium (mg/L) Sodium (mg/L) Sulfates (mg/L SO4)

GSCA-4/2024

Drinking water

Drinking Water and Freshwater

MA: Ammonium (mg/L)

MB: True color (mg/L Pt/Co), Turbidity (UNF)

MC: Conductivity at 20ºC (µS/cm)(2), Hardness (mg/L CaCO3), Fluorides (mg/L), Phosphates (mg/L as phosphate ion), Total phosphorus (mg/L P), Nitrates (mg/L), Nitrites (mg/L)(1), pH (pH units)(2), Potassium (mg/L), Sodium (mg/L)

MD: Chlorates (mg/L)(3), Chlorites (mg/L)(3)

GSCAR-1 2025

Wastewater

Wastewater

MA: COPPER (mg/L), TOTAL CHROMIUM (µg/L Cr), COD (mg O2/L), PHOSPHATES (mg/L), FLUORIDES (mg/L), TOTAL PHOSPHORUS (mg/L P), IRON (mg/L Fe), MERCURY (µg/L Hg), NITRATES (mg/L), AMMONIUM NITROGEN (mg/L N), KJELDAHL NITROGEN (mg/L N), TOTAL NITROGEN (mg/L N)

MB: CHLORIDES (mg/L as chloride ion), CONDUCTIVITY AT 25ºC (µS/cm), BOD5 (mg O2/L), pH (upH)

MC: SUSPENDED SOLIDS (mg/L)

GSCAR-2 2024

Wastewater

Aguas residuales

MA: ARSENIC (mg/L), CADMIUM (mg/L), COT (mg/L), ANIONIC DETERGENTS (mg Sodium Lauryl Sulfate/L)(1), COD (mg O2/L), PHENOLS (mg/L)(1), LEAD (mg/L),

MB: CHROMIUM VI (mg/L)(1)

MC: BOD5 (mg O2/L)(1)(3), pH (upH)(2)

MD: CHLORIDES (mg/L), CONDUCTIVITY AT 25 ºC (mS/cm)(2), SUSPENDED SOLIDS (mg/L)(4)

ME: CATIONIC DETERGENTS (mg/L)(1)

GSCAR-3/2024

Wastewater

WASTEWATER

MA: COD (mg O2/L)(5), TOTAL PHOSPHORUS (mg/L P), MERCURY (µg/L Hg), NICKEL (µg/L), KJELDAHL NITROGEN (mg/L N), ZINC (µg/L)

MB: CONDUCTIVITY AT 25 ºC (µS/cm) (3), BOD5 (mg O2/L) (1)(2), PH (upH) (3)

MC: SUSPENDED SOLIDS (mg/L) (4)

ME: BARIUM (mg/L), TIN (mg/L)

GSCAR-4 2024

Wastewater

Wastewater

M1: TOXICITY (INHIBITORY SUBSTANCES), EQUITOX

M2: TOXICITY (INHIBITORY SUBSTANCES), EQUITOX

GSCMAC-1/2025

Drinking water

Water for human consumption and inland waters: Metals

M1: Aluminum (µg/L) Cadmium (µg/L) Copper (µg/L) Total Chromium (µg/L) Iron (µg/L) Manganese (µg/L) Mercury (µg/L) Nickel (µg/L) Lead (µg/L) Zinc (µg/L)

GSCNU 2024

Prepared dish (Chickpea salad)

Nutritional composition in foods

M1: Total sugars (% w/w), Calcium (mg/100g)*, Ashes (% w/w), Energy (kcal/100g)*, Dietary fiber (% w/w)*, Total phosphorus (mg/100g)*, Crude fat with prior hydrolysis (% w/w), Saturated fats (% w/w)*, Metabolizable carbohydrates (% w/w)*(2), Total carbohydrates (% w/w)*(2), Moisture (% w/w)(1), Crude protein (N × 6.25) (% w/w), Sodium (mg/100g)

GSCSLU/2024

Sludge

M1: Total calcium (% (CaO) d.w.)* Conductivity at 25ºC (1:5) (µS/cm)* Total phosphorus (% (P2O5) d.w.)* Iron (mg/kg d.w.)* Total magnesium (% (MgO) d.w.)* Organic matter (% d.w.) Dry matter (%) Kjeldahl nitrogen* (% d.w.)* pH (1:5) (in aqueous extract) (pH units)* Total potassium (% (K2O) d.w.)*

GSCSU/2024

Agricultural Soils

Agricultural Soils

M1: Ammonium acetate-extractable calcium (not CIC corrected) (meq/100g soil), Active limestone (% CaCO3 soil)*, Cation exchange capacity (meq/100g soil), Calcium carbonate (% CaCO3 soil)*, Conductivity at 25ºC (1:2.5) (on aqueous extract) (mS/cm), Conductivity at 25ºC (1:5) (on aqueous extract) (mS/cm), Olsen phosphorus (mg/kg P soil), Moisture (%) (1), Ammonium acetate-extractable magnesium (not CIC corrected) (meq/100g soil), Total organic matter (% soil), Nitrates (mg/kg soil)*, Kjeldahl nitrogen (% N soil), Total nitrogen (% N soil), pH (1:2.5) (on aqueous extract) (-), pH (1:5) (on aqueous extract) (-), Ammonium acetate-extractable potassium (meq/100g soil), Ammonium acetate-extractable sodium (meq/100g soil)*, USDA texture (% clay) (% clay)*, USDA texture (% sand) (% sand), USDA texture (% silt) (% silt)