A sampling apparatus for use in performing electrical measurements on a liquid sample containing blood, the apparatus comprising: two or more current output terminals (16, 17) for outputting an alternating current signal applied therebetween; an alternating electrical current unit in electrical communication with the two or more current output terminals adapted to apply thereto an alternating electrical current of a given amplitude and frequency when a said liquid sample is in electrical connection between the two or more current output terminals; a voltage unit in electrical communication with the two or more current output terminals adapted to apply therebetween a direct electrical potential difference of a given magnitude; a first voltage input terminal adapted to receive a first electrical signal externally input thereto and a separate second voltage input terminal adapted to receive a second electrical signal externally input thereto when said liquid sample is in electrical connection between the first and second voltage input terminals; at least one voltage detector adapted to measure a first voltage and a second voltage using said first and second electrical signals, respectively; a control unit arranged to control the alternating electrical current unit to apply a said alternating electrical current of said given frequency and concurrently to control the voltage unit and the at least one voltage detector to measure said first and second voltages both when said direct electrical potential difference is applied and when said direct electrical potential difference is not applied; a calculating unit arranged to calculate a first electrical reactance value (X 1) using the first and second voltages measured when said direct electrical potential difference is applied, and to calculate a second electrical reactance value (X 2) measured when said direct electrical potential difference is not applied; wherein the calculating unit is arranged to generate a value representing the concentration of glycated haemoglobin (HbA1c) in the liquid sample according to the first electrical reactance value (X 1), the second electrical reactance value (X 2) and a value representing the relative volume of red blood cells in the liquid sample (haematocrit). two or more current output terminals (16, 17) for outputting an alternating current signal applied therebetween; an alternating electrical current unit in electrical communication with the two or more current output terminals adapted to apply thereto an alternating electrical current of a given amplitude and frequency when a said liquid sample is in electrical connection between the two or more current output terminals; a voltage unit in electrical communication with the two or more current output terminals adapted to apply therebetween a direct electrical potential difference of a given magnitude; a first voltage input terminal adapted to receive a first electrical signal externally input thereto and a separate second voltage input terminal adapted to receive a second electrical signal externally input thereto when said liquid sample is in electrical connection between the first and second voltage input terminals; at least one voltage detector adapted to measure a first voltage and a second voltage using said first and second electrical signals, respectively; a control unit arranged to control the alternating electrical current unit to apply a said alternating electrical current of said given frequency and concurrently to control the voltage unit and the at least one voltage detector to measure said first and second voltages both when said direct electrical potential difference is applied and when said direct electrical potential difference is not applied; a calculating unit arranged to calculate a first electrical reactance value (X 1) using the first and second voltages measured when said direct electrical potential difference is applied, and to calculate a second electrical reactance value (X 2) measured when said direct electrical potential difference is not applied; wherein the calculating unit is arranged to generate a value representing the concentration of glycated haemoglobin (HbA1c) in the liquid sample according to the first electrical reactance value (X 1), the second electrical reactance value (X 2) and a value representing the relative volume of red blood cells in the liquid sample (haematocrit).