Calibration Curve
Equation for the straight line  y=0.017x – 0.0935
to get the concentration values for the samples, we re-arrange this equation:
x = (y+0.0935)/0.017, where x = concentration and y = absorbance
Sample Absorbances
Sample concentrations
A = 0.988
SS1 = 0.851
H1 = 0.880
H2 = 1.034
H3 = 0.630
H4 = 0.731
63.6 mg/ dL
55.6 mg/ dL
57.3 mg/ dL
66.3 mg/ dL
42.6 mg/ dL
48.5 mg/ dL
some samples were diluted:
H1 = 1 in 5 therefore H1 concentration = 286.5 mg/dL
H2 = 1 in 2 therefore H2 concentration = 132.6 mg/dL
H3 = 1 in 2 therefore H3 = 85.2 mg/ dL
Final Sample Concentrations:
A = 63.6 mg/dL:
slightly low, just outside 70 mg/dL, could be a normal sample
SS1 = 55.6 mg/ dL: low, indication of hypoglycaemia
H1 = 286.5 mg/ dL: extremely high - hyperglycaemic
H2 = 132.6 mg/dL: high, hyperglycaemic
H3 = 85.2 mg/dL:
within 70 – 99 mg/dl range, normal sample
H4 = 48.5 mg/dL:
low, indicates hypoglycaemia, several possibilities
Diagnosis/Discussion of Sample Concentrations
A: although slightly low, the value is not extreme, so most likely the patient is
healthy, and results can be altered slightly due to other influences such as the patient’s
age or the measurement method.
H3: Normal glucose levels
SS1 & H4: Samples are in a hypoglycaemic state. Patients may show any of the
following symptoms:
Shakiness
Palpitations
Sweating, although cold
Dilating Pupils
Hunger or Nausea
Fatigue, confusion and irritability
Slurred Speech
Impaired Judgement
Headaches
Seizures
Coma
Not all occur in every case, and do not occur in a set order. There are numerous
causes for hypoglycaemia. Specific manifestations vary by age and by severity of the
hypoglycemia. In young children vomiting often accompanies morning hypoglycemia
with ketosis. In older children and adults, moderately severe hypoglycemia can
resemble mania, mental illness, drug intoxication, or drunkenness. In the elderly,
hypoglycemia can produce focal stroke-like effects or a hard-to-define malaise. The
symptoms of a single person do tend to be similar from episode to episode.
If the patient is newborn:
Prematurity, Maternal Diabetes, Sepsis or Prolonged fasting, Congenital
Hypopituitarism/Hyperinsulinism
If the patient is a child:
Diarrhoea, Growth Hormone Deficiency, Idiopathic Ketogenic Hypoglycaemia,
Insulin excess, Ingestion of something such as mouthwash
Adult patients:
Injected insulin, used for type 1 diabetes
Insulin secreting pancreatic tumour
Addison’s Disease
Sepsis
Acquired hypopituitarism and adrenal insufficiency in older adults.
Samples H1 & H2: Show hyperglycaemic signs. The fasting levels are both over
126mg/dL, which is very serious as sustained high levels of blood glucose can
damage blood vessels and the organs which they supply. The high levels could be due
to 2 causes:
Diabetes – hyperglycaemia is a classic symptom of Diabetes Mellitus (others being
constant thirst and excessive urination), which has an unknown cause and an
unknown cure. Other symptoms that the patients may be showing include:
Blurred vision, Fatigue, weight loss, poor healing of wounds, impotence, dry mouth,
recurrent infections.
These symptoms do not normally occur with acute non-diabetic hyperglycaemia, but
some occur with the chronic form of the condition (with the exception of weight loss).
Non-diabetic Hyperglycemia – mainly caused by obesity, and the condition can be
helped by removing the body’s fat reserves through exercise and maintaining a
healthy diet. Excess white fat in the body disrupts the body’s ability to absorb and use
insulin. Other causes of non-diabetic hyperglycemia are eating disorders, such as
Bulimia – where the person will binge-eat, causing a rapid increase in calorie intake.
Percentage Purity of Sample A
Glycogen + Water  Glucose
Glycogen’s Mr = 162
Water’s Mr = 18 therefore Glucose Mr = 180
A = 700mg = 0.7g
no. of moles = mass/ Mr = 0.7/162 = 4.32x10-3 moles
Mass = no. moles x Mr = 0.778 = 778mg
Sample A’s Mr = 636
Percentage Purity – 636/778 x 100 = 81.74%