Estimation of Salicylate in Urine

1 a) Table showing distilled water and salicylate solution required to make absorbance and range of standard concentrations read at 540nm

|Distilled water (ml) |Range Salicylate |Salicylate |Absorbance (540nm) |Specific Absorbance |Mean specific |
| |solutions (ml) |concentration (mg/L) | |(Abs – Blank) |Absorbance (540nm) |
| | | |1 |2 |1 |2 | |
|0.5 |0 |0 |0.021 |0.021 |0.021 |0.021 |0.021 |
|0.4 |0.1 |50 |0.082 |0.079 |0.061 |0.058 |0.060 |
|0.3 |0.2 |100 |0.146 |0.156 |0.125 |0.135 |0.130 |
|0.2 |0.3 |150 |0.235 |0.243 |0.214 |0.222 |0.218 |
|0.1 |0.4 |200 |0.334 |0.340 |0.313 |0.319 |0.316 |
|0 |0.5 |250 |0.374 |0.372 |0.353 |0.351 |0.352 |

b) Calculation for Specific Absorbance:

Specific Absorbance = (Obtained solution Absorbance – Blank Absorbance) 2
E.g. (0.082 – 0.021) = 0.060nm 2
Calculation of standard salicylate concentration:

Standard salicylate concentration = C1V1 = C2V2

E.g. C2 = C1 × V1 V2 C2 = 250 × 0.3 C2 = 150mg/L 0.5
C1 = Initial concentration of salicylate (250 mg/L)

C2 = Final concentration of salicylate

V1 = Initial volume and V2 = Final volume (0.5)

C. Refer to the graph attached

d). Table below showing the volume of urine produced by patient A & B at different intervals and their absorbance at 540nm.

|Patient A |Absorbance (540nm) |Specific Absorbance |Salicylate Concentration |Mean Salicylate |Volume of Urine |Volume of |
|Sample No. | |(Abs – Blank) |(mg/L) |concentration (mg/L |produced (L) |salicylate |
| | | | | | |excreted in urine|
| | | | | | |(mg) |
| |1 |2 |1 |2 |1 |2 | |

e). Calculation of Volume of urine produced:

E.g. Unknown sample A3: 130 1000 = 0.130 L

Calculation of Volume of salicylate excreted in urine :

E.g. Volume of urine produced × Mean salicylate concentration

Patient A3: 0.130 × 155 = 20.15mg.

Total salicylate excreted in urine = 285.89mg

f. The dipstick test result for patients B displayed a light purple colour and ++2 ketone level (40-100mg/dl). This suggests presence of ketone in the patient urine sample and very low amount of aspirin.

g. Patient A: David Beckham. Gender: Male Age: 35

Patient B: Cruz Beckham. Gender: Male Age: 6

Estimation of Paracetamol in serum

1 a). Table showing the absorbance reading at 430nm for paracetamol serum for patient C, D and Blank and standard paracetamol.

|Patient sample |Absorbance (430nm) |Average absorbance – Blank |Paracetamol in serum (mg/L) |
| | |(430nm) |