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Units and proportions

1 milligram per kilogram / 1 part per million
A visualisation of the proportions between the same root units of measurement puts them into perspective.
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Putting proportions into perspective

 
When we measure the presence of a compound in a sample, we usually work with concentrations, or proportions.
 
When using a specific unit (milligram), as long as we compare it to the same root unit (gram), the answer is a proportion and can be shown in % simply by multiplying by the relevant power of 10.
 
FOR EXAMPLE:
  • 50 mg/g = 5%
  • 50 g/kg = 5%
  • 50 ml/l = 5%
  • 50 mg/kg = 0.005%
 
However, for liquid samples, you sometimes want to know the presence of a compound in milligram (a unit of mass) per milliliter (a unit of volume) of the sample. This is not a simple proportion and requires that you know the density of the liquid. And unless the density is exactly 1g/ml, converting the result to a percentage is not merely as simple as decreasing by a factor of 10.

Per cent

We’re all quite used to the concept of percentages, having been introduced to them at school level already. The literal meaning is “per hundred”.

EXAMPLE: 1% = 1 out of every 100

To put 1% in perspective, think of it as the bit of a joint you get when sharing it equally with 99 of your closest friends.

Milligram per gram / part per thousand

In units of mass, a milligram per gram is the same as a part per thousand. The prefix “milli” refers to a thousandth.

EXAMPLE: 1 mg/g = 1 out of every 1 000

To put 1 mg/g in perspective, consider the portion of the width of a rugby field covered by the length of a 70mm joint.

Milligram per kilogram / part per million

While “milli” refers to a thousandth, the prefix “kilo” refers to a thousand. A gram is a thousand times a milligram, and a kilogram is a thousand times a gram. This means a milligram per kilogram is a part per million 

EXAMPLE: 1 mg/kg or 1 ppm = 1 out of every 1 000 000

It’s harder to perceive such a minute amount. Imagine the part of the NI between Cape Town and Johannesburg traversed by lining up twenty 70mm joints. That is roughly a part per million.

Microgram per kilogram / part per billion

Going deeper, a microgram is a thousandth of a milligram, a millionth of a gram, and a billionth of a kilogram. This means a microgram per kilogram is a part per billion.

EXAMPLE: 1 µg/kg or 1 ppb = 1 out of every 1 000 000 000

A part per billion roughly equates to the length of five 70mm joints stacked on top of each other as a portion of the distance to the moon.

The units you can expect in our certificates of analysis

mg/g & %Potency & Cannabinoids, and Terpene Analysis
mg/ml Potency & Cannabinoids, and Terpene Analysis on liquid samples where a Density Measurement was performed
g/mlDensity Measurement
%Moisture Content and Total Ash
cfu/gMicrobial Count (colony forming units per gram)
ppmResidual Solvents
µg/kg (ppb)Heavy Metals
mg/kg (ppm)Mycotoxins and Pesticides

Thank goodness for the metric system!

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    Pesticides we can test for

    The standard multi-residue analysis includes testing for:

    2-Phenylphenol
    2,4′-DDE
    2,4′-DDT
    4,4′-DDE
    4,4′-DDT
    Abamectin B1a
    Abamectin B1b
    Acephate
    Acetamiprid
    Acetochlor
    Acibenzolar-S-methyl
    Acrinathrin
    Aldicarb
    Aldicarb sulfone
    Aldicarb sulfoxide
    Aldrin
    Ametoctradin
    Amitraz
    Azadirachtin
    Azinphos-ethyl
    Azinphos-methyl
    Azoxystrobin
    BAC-C10
    BAC-C12
    BAC-C14
    BAC-C16
    BAC-C8
    Benthiavalicarb isopropyl
    Bifenthrin
    Bitertanol
    Boscalid
    Bromophos-methyl
    Bupirimate
    Buprofezin
    Cadusafos
    Captan
    Carbaryl
    Carbendazim
    Carfentrazone-ethyl
    Chinomethionate
    Chlorantraniliprole
    Chlordane
    Chlorfenapyr
    Chlorothalonil
    Chlorpyrifos
    Chlorthal-dimethyl
    Clofentezine
    Clothianidin
    Coumaphos
    Cyfluthrin
    Cyhalothrin-lambda
    Cymoxanil
    Cypermethrin (sum of isomers)
    Cyprodinil
    DDAC-C10
    DDAC-C8
    Deltamethrin
    Demeton-S-methyl
    Demeton-S-methyl sulfone
    Diazinon
    Dichloran
    Dichlorophene
    Dichlorvos
    Dieldrin
    Difenoconazole
    Diflubenzuron
    Dimethoate
    Dimethomorph
    Diphenylamine
    Dodine
    Emamectin benzoate B1a
    Emamectin benzoate B1b
    Endosulfan-alpha
    Endosulfan-beta
    Esfenvalerate
    Etaconazole
    Ethofenprox
    Ethoprophos
    Etoxazole
    Famoxadone
    Fenamidone
    Fenamiphos
    Fenarimol
    Fenazaquin
    Fenbuconazole
    Fenbutatin oxide
    Fenhexamid
    Fenoxycarb
    Fenpropathrin
    Fenpyroximate
    Fenthion
    Fenvalerate
    Flufenoxuron
    Flumioxazin
    Fluopicolide
    Fluopyram
    Flusilazole
    Flutriafol
    Fluxapyroxad
    Folpet
    Forchlorfenuron
    Formetanate (hydrochloride)
    Fosthiazate
    Hexaconazole
    Imazalil
    Imidacloprid
    Indoxacarb
    Iprodione
    Iprodione (GC)
    Iprovalicarb
    Isazophos
    Isofenphos
    Kresoxim-methyl
    Lufenuron
    Malathion
    Mandipropamid
    Metalaxyl-M
    Methamidophos
    Methidathion
    Methiocarb
    Methomyl
    Methoxyfenozide
    Metrafenone
    Mevinphos-cis
    Mevinphos-trans
    Monocrotophos
    Myclobutanil
    Omethoate
    Oxamyl
    Oxydemeton-methyl
    Oxyfluorfen
    Paclobutrazol
    Parathion
    Parathion-methyl
    Penconazole
    Permethrin (sum of isomers)
    Phenthoate
    Phosmet
    Piperonyl butoxide
    Pirimicarb
    Prochloraz
    Procymidone
    Profenofos
    Propamocarb
    Propargite
    Propiconazole
    Propoxur
    Propyzamide
    Proquinazid
    Prothiofos
    Pymetrozin
    Pyraclostrobin
    Pyrimethanil
    Pyrimethanil (GC)
    Pyriproxyfen
    Quinoxyfen
    Simazine
    Spinetoram
    Spinosad
    Spirodiclofen
    Spirotetramat
    Spiroxamine
    Sulfoxaflor
    Tau-fluvalinate
    Tau-fluvalinate
    Tebuconazole
    Temephos
    Terbufos
    Tetraconazole
    Tetradifon
    Thiabendazole
    Thiacloprid
    Thiamethoxam
    Thidiazuron
    Thiophanate-methyl
    Triadimefon
    Triadimenol
    Triazophos
    Trichlorfon
    Trifloxystrobin
    Triflumuron
    Trifluralin
    Triforin
    Vinclozolin
    Zoxamide

    Please enquire for specific tests.